Total or Partial Knee Arthroplasty Trial - TOPKAT: study protocol for a randomised controlled trial Long-term Results of Autologous Chondrocyte Implantation in the Knee for Chronic Chondral and Osteochondral Defects Outcomes After a Single-Stage Procedure for Cell-Based Cartilage Repair Increased Failure Rate of Autologous Chondrocyte Implantation after Previous Treatment with Marrow Stimulation Techniques The Cost Utility of Autologous Chondrocytes Implantation Using ChondroCelect® in Symptomatic Knee Cartilage Lesions in Belgium NeoCart, an autologous cartilage tissue implant, compared with microfracture for treatment of distal femoral cartilage lesions: an FDA phase-II prospective, randomized clinical trial after two years. Osteoarthritis Classification Scales: Interobserver Reliability and Arthroscopic Correlation. Knee biomechanics during walking gait following matrix-induced autologous chondrocyte implantation. Accelerated Weightbearing Rehabilitation After Matrix-Induced Autologous Chondrocyte Implantation in the Tibiofemoral Joint Autologous Chondrocyte Implantation for Joint Preservation in Patients with Early Osteoarthritis Autologous Chondrocyte Implantation and Osteochondral Cylinder Transplantation in Cartilage Repair of the Knee Joint: A Prospective, Comparative Trial Does Patient Sex Influence Cartilage Surgery Outcome? Arthroscopic second generation autologous chondrocyte implantation Sequential outcome following autologous chondrocyte implantation of the knee: A six-year follow-up A prospective, randomised study comparing two techniques of autologous chondrocyte implantation for osteochondral defects in the knee: Periosteum covered versus type I/III collagen covered. Clinical Outcome of Autologous Chondrocyte Implantation at 5 Years in US Subjects Enhanced secondary analysis of survival data: reconstructing the data from published Kaplan-Meier survival curves Treatment and Prevention of (Early) Osteoarthritis Using Articular Cartilage Repair—Fact or Fiction? A Systematic Review Matrix assisted autologous chondrocyte transplantation for cartilage treatment Autologous chondrocyte implantation versus matrix-induced autologous chondrocyte implantation for osteochondral defects of the knee: a prospective, randomised study. A prospective, randomised comparison of autologous chondrocyte implantation versus mosaicplasty for osteochondral defects in the knee. BST-CarGel® Treatment Maintains Cartilage Repair Superiority over Microfracture at 5 Years in a Multicenter Randomized Controlled Trial Comparing Responsiveness of Six Common Patient-Reported Outcomes to Changes Following Autologous Chondrocyte Implantation Results at 10–14 years after microfracture treatment of articular cartilage defects in the knee Arthroscopic Second-Generation Autologous Chondrocyte Implantation Compared with Microfracture for Chondral Lesions of the Knee Matrix-induced autologous chondrocyte implantation versus microfracture in the treatment of cartilage defects of the knee: a 2-year randomised study Long-term results after microfracture treatment for full-thickness knee chondral lesions in athletes Cost and health status analysis after autologous chondrocyte implantation and mosaicplasty: a retrospective comparison. Ten-Year Follow-up of a Prospective, Randomized Clinical Study of Mosaic Osteochondral Autologous Transplantation Versus Microfracture for the Treatment of Osteochondral Defects in the Knee Joint of Athletes Activity levels are higher after osteochondral autograft transfer mosaicplasty than after microfracture for articular cartilage defects of the knee: a retrospective comparative study. The relationship of anxiety and depression with self-reported knee pain in the community: data from the Baltimore Longitudinal Study of Aging. Treatment of Deep Cartilage Defects of the Knee Using Autologous Chondrograft Transplantation and by Abrasive Techniques — A Randomized Controlled Study Five-Year Outcome of Characterized Chondrocyte Implantation Versus Microfracture for Symptomatic Cartilage Defects of the Knee Matrix-Applied Characterized Autologous Cultured Chondrocytes Versus Microfracture Treatment of Symptomatic Cartilage Defects of the Knee A Randomized Trial Comparing Accelerated and Traditional Approaches to Postoperative Weightbearing Rehabilitation After Matrix-Induced Autologous Chondrocyte Implantation Comparison of osteochondral autologous transplantation, microfracture, or debridement techniques in articular cartilage lesions associated with anterior cruciate ligament injury: a prospective study with a 3-year follow-up. A randomized trial comparing autologous chondrocyte implantation with microfracture. Findings at five years. Comparative Evaluation of Autologous Chondrocyte Implantation and Mosaicplasty: A Multicentered Randomized Clinical Trial Arthroscopic washout of the knee--a 5-year survival analysis. [Osteochondral transplantation versus autogenous chondrocyte transplantation. A prospective comparative clinical study]. Microfracture treatment of single or multiple articular cartilage defects of the knee: a 5-year median follow-up of 110 patients A controlled trial of arthroscopic surgery for osteoarthritis of the knee. Arthroscopic validation of radiographic grading scales of osteoarthritis of the tibiofemoral joint. Articular debridement versus washout for degeneration of the medial femoral condyle. A five-year study. Minimum ten-year results of a prospective randomised study of autologous chondrocyte implantation versus mosaicplasty for symptomatic articular cartilage lesions of the knee. Current Treatments of Isolated Articular Cartilage Lesions of the Knee Achieve Similar Outcomes [MRI in the follow-up of matrix-supported autologous chondrocyte transplantation (MACI) and microfracture]. The John Insall Award: A Minimum 10-year Outcome Study of Autologous Chondrocyte Implantation Autologous chondrocyte implantation compared with microfracture in the knee. A randomized trial. Clinical and Magnetic Resonance Imaging–Based Outcomes to 5 Years After Matrix-Induced Autologous Chondrocyte Implantation to Address Articular Cartilage Defects in the Knee Characterized Chondrocyte Implantation Results in Better Structural Repair When Treating Symptomatic Cartilage Defects of the Knee in a Randomized Controlled Trial versus Microfracture Autologous Chondrocyte Implantation in the Patella
Background In the majority of patients with osteoarthritis of the knee the disease originates in the medial compartment . There are two fundamentally different approaches to knee replacement for patients with unicompartmental disease : some surgeons feel that it is always best to replace both the knee compartments with a total knee replacement ( TKR ) ; whereas others feel it is best to replace just the damaged component of the knee using a partial or unicompartment replacement ( UKR ) . Both interventions are established and well-documented procedures . Little evidence exists to prove the clinical and cost-effectiveness of either management option . This provides an explanation for the high variation in treatment of choice by individual surgeons for the same knee pathology . The aim of the TOPKAT study will be to assess the clinical and cost effectiveness of TKRs compared to UKRs in patients with medial compartment osteoarthritis . Methods / Design The design of the study is a single layer multicentre superiority type r and omised controlled trial of unilateral knee replacement patients . Blinding will not be possible as the surgical scars for each procedure differ . We aim to recruit 500 patients from approximately 28 secondary care orthopaedic units from across the UK including district general and teaching hospitals . Participants will be r and omised to either UKR or TKR . R and omisation will occur using a web-based r and omisation system . The study is pragmatic in terms of implant selection for the knee replacement operation . Participants will be followed up for 5 years . The primary outcome is the Oxford Knee Score , which will be collected via question naires at 2 months , 1 year and then annually to 5 years . Secondary outcomes will include cost-effectiveness , patient satisfaction and complications data .Trial registration Current Controlled Trials IS RCT N03013488 ; Clinical Trials.gov Identifier : Background : Autologous chondrocyte implantation ( ACI ) has been shown to be effective in the midterm for the treatment of symptomatic articular cartilage lesions of the knee , but few long-term series have been published . The multioperated chronic articular cartilage defect remains a difficult condition to treat . Purpose : To examine the long-term clinical results of ACI for large chronic articular cartilage defects , many treated as salvage . Study Design : Case series ; Level of evidence , 4 . Methods : This is a prospect i ve case series of 104 patients with a mean age of 30.2 years and a symptomatic lesion of the articular cartilage in the knee , who underwent ACI between 1998 and 2001 . The mean duration of symptoms before surgery was 7.8 years . The mean number of previous surgical procedures on the cartilage defect , excluding arthroscopic debridement , was 1.3 . The defects were large , with a mean size of 477.1 mm2 ( range , 120 - 2500 mm2 ) . The modified Cincinnati , Stanmore/Bentley , and visual analog scale for pain scoring systems were used to assess pain and functional outcomes at a minimum 10 years ( mean , 10.4 years ; range , 10 - 12 years ) . Results : Twenty-seven patients ( 26 % ) experienced graft failure at a mean of 5.7 years after ACI . Of the 73 patients who did not fail , 46 patients ( 63 % of patients with a surviving graft ) had an excellent result , 18 ( 25 % ) were good , 6 ( 8 % ) were fair , and 3 ( 4 % ) had a poor result . Of a total of 100 patients successfully followed up , 98 were satisfied with the ACI technique for their chronic knee pain and would undergo the procedure again . Conclusion : Autologous chondrocyte implantation can provide a long-term solution in more than 70 % of young patients of a difficult-to-treat group with large chronic articular cartilage lesions , even in the salvage situation Background : There are currently several approaches being pursued to treat focal defects of articular cartilage , each having specific advantages or challenges . A single-stage procedure that uses autologous cartilage fragments , Cartilage Autograft Implantation System ( CAIS ) , is being evaluated in patients and may offer a clinical ly effective option . Purpose : To establish the safety of CAIS and to test whether CAIS improves quality of life by using st and ardized outcomes assessment tools . Study Design : R and omized controlled trial ; Level of evidence , 2 . Methods : Patients ( n = 29 ) were r and omized ( 1:2 ) with the intent to treat with either a  control ( microfracture [ MFX ] ) or an experimental ( CAIS ) procedure . Patients were followed at predetermined time points for 2 years using several st and ardized outcomes assessment tools ( SF-36 , International Knee Documentation Committee [ IKDC ] , Knee injury and Osteoarthritis Outcome Score [ KOOS ] ) . Magnetic resonance imaging was performed at baseline , 3 weeks , and 6 , 12 , and 24 months . Results : Lesion size and International Cartilage Repair Society ( ICRS ) grade were similar in both groups . General outcome measures ( eg , physical component score of the SF-36 ) indicated an overall improvement in both groups , and no differences in the number of adverse effects were noted in comparisons between the CAIS and MFX groups . The IKDC score of the CAIS group was significantly higher ( 73.9 ± 14.72 at 12 months and 82.95 ± 14.88 at 24 months ) compared with the MFX group ( 57.78 ± 18.31 at 12 months and 59.5 ± 13.44 at 24 months ) . Select subdomains ( 4/5 ) in the KOOS instrument were significantly different at 12 and 18 months , and all subdomains ( Symptoms and Stiffness , Pain , Activities of Daily Living , Sports and Recreation , Knee-related Quality of Life ) were significantly increased at 24 months in CAIS with scores of 88.47 ± 11.68 , 90.64 ± 7.87 , 97.29 ± 3.8 , 78.16 ± 22.06 , and 69 ± 23.15 compared with 75 ± 9.31 , 78.94 ± 13.73 , 89.46 ± 8.13 , 51.67 ± 26.01 , and 37.15 ± 21.67 in the MFX group . These significant improvements were maintained at 24 months in both IKDC and KOOS . Qualitative analysis of the imaging data did not note differences between the 2 groups in fill of the graft bed , tissue integration , or presence of subchondral cysts . Patients treated with MFX had a significantly higher incidence of intralesional osteophyte formation ( 54 % and 70 % of total number of lesions treated ) at 6 and 12 months when compared with CAIS ( 8 % and 25 % of total number of lesions treated ) . Conclusion : The first clinical experience in using CAIS for treating patients with focal chondral defects indicates that it is a safe , feasible , and effective method that may improve long-term clinical outcomes Background Marrow stimulation techniques such as drilling or microfracture are first-line treatment options for symptomatic cartilage defects . Common knowledge holds that these treatments do not compromise subsequent cartilage repair procedures with autologous chondrocyte implantation . Hypothesis Cartilage defects pretreated with marrow stimulation techniques will have an increased failure rate . Study Design Cohort study ; Level of evidence , 2 . Methods The first 321 consecutive patients treated at one institution with autologous chondrocyte implantation for full-thickness cartilage defects that reached more than 2 years of follow-up were evaluated by prospect ively collected data . Patients were grouped based on whether they had undergone prior treatment with a marrow stimulation technique . Outcomes were classified as complete failure if more than 25 % of a grafted defect area had to be removed in later procedures because of persistent symptoms . Results There were 522 defects in 321 patients ( 325 joints ) treated with autologous chondrocyte implantation .  On average , there were 1.7 lesions per patient . Of these joints , 111 had previously undergone surgery that penetrated the subchondral bone ; 214 joints had no prior treatment that affected the subchondral bone and served as controls . Within the marrow stimulation group , there were 29 ( 26 % ) failures , compared with 17 ( 8 % ) failures in the control group . Conclusion Defects that had prior treatment affecting the subchondral bone failed at a rate 3 times that of nontreated defects . The failure rates for drilling ( 28 % ) , abrasion arthroplasty ( 27 % ) , and microfracture ( 20 % ) were not significantly different , possibly because of the lower number of microfracture patients in this cohort ( 25 of 110 marrow-stimulation procedures ) . The data demonstrate that marrow stimulation techniques have a strong negative effect on subsequent cartilage repair with autologous chondrocyte implantation and therefore should be used judiciously in larger cartilage defects that could require future treatment with autologous chondrocyte implantation Abstract Background : Knee cartilage lesions increase the risk of developing osteoarthritis ( OA ) , and may eventually result in a total knee replacement ( TKR ) . There is currently no consensus on the optimal treatment of cartilage lesions . ChondroCelect ® ( CC ) is a cell-based therapy approved for use in autologous chondrocytes implantation ( ACI ) to treat symptomatic cartilage defects of the femoral condyle . Its capacity to safely restore good- quality cartilage was demonstrated in a r and omized controlled trial ( RCT ) versus the surgical procedure microfracture ( MFX ) . Objective : This study investigated the cost utility of CC used in ACI compared with MFX to treat symptomatic knee cartilage lesions in Belgium . Methods : A decision tree model comparing CC with MFX over a 40-year horizon was developed in TreeAge Pro ™ . The key timepoints of the model were ( i ) clinical assessment 5 years after initial intervention ( success or no success , with or without re-operation ) ; ( ii ) development of OA at 15 years ( yes/no ) ; ( iii ) need for TKR at 20 years ( yes/no ) ; and ( iv ) need for prosthesis revision at 35 years ( yes/no ) . Clinical data provided by the RCT of CC versus MFX were the clinical success ( response ) rate based on the Knee injury and Osteoarthritis Outcome Score ( KOOS ) at 36 months ( 82.9 % vs 62.0 % ; p = 0.048 ) and the proportion of good structural repair/presence of hyaline cartilage based on International Cartilage Repair Society ( ICRS II ) visual item at 12 months ( 44.9 % vs 23.2 % ; p= 0.023 ) . Utility scores by surgery outcome were derived from the SF-36 question naire responses collected in the RCT . Conservative assumptions related to the incidences of OA , TKR and prosthesis revision relied on a literature search . A patient chart review ( n = 82 ) provided follow-up costs by surgery outcome . National tariffs were applied to direct medical re sources used ( healthcare payer perspective , year 2008 costs ) . Annual discounting was applied to costs ( 3 % ) and effects ( 1.5 % ) as recommended by the Belgian pharmacoeconomic guidelines . Results : The incremental cost per QALY gained for CC compared with MFX was € 16 229 , with a difference in costs of € 20 802 and 1.282 QALYs gained . Sensitivity analyses indicated that the key model drivers were the proportion of patients with hyaline cartilage and the correlation between hyaline cartilage formation and later avoidance of OA . Probabilistic sensitivity analyses showed robustness of the results , with 80 % of the simulations below the usual UK National Institute for Health and Clinical Excellence ( NICE ) threshold of € 22 000 per QALY . Conclusions : Assuming a good correlation between high- quality cartilage repair and avoidance of OA at a later stage , the benefits of the cell therapy CC over MFX in terms of QALYs gained and OA-related costs avoided appear real . Further research is required to explore long-term effects of cartilage repair and reduce uncertainty on quality of life of patients with OA before and after joint replacement BACKGROUND Despite introduction of autologous chondrocyte therapy for repair of hyaline articular cartilage injury in 1994 , microfracture remains a primary st and ard of care . NeoCart , an autologous cartilage tissue implant , was compared with microfracture in a multisite prospect i ve , r and omized trial of a tissue-engineered bioimplant for treating articular cartilage injuries in the knee . METHODS Thirty patients were r and omized at a ratio of two to one ( two were treated with an autologous cartilage tissue implant [ NeoCart ] for each patient treated with microfracture )  at the time of arthroscopic confirmation of an International Cartilage Repair Society ( ICRS ) grade -III lesion(s ) . Microfracture or cartilage biopsy was performed . NeoCart , produced by seeding a type-I collagen matrix scaffold with autogenous chondrocytes and bioreactor treatment , was implanted six weeks following arthroscopic cartilage biopsy . St and ard evaluations were performed with vali date d clinical outcomes measures . RESULTS Three , six , twelve , and twenty-four-month data are reported . The mean duration of follow-up ( and st and ard deviation ) was 26 ± 2 months . There were twenty-one patients in the NeoCart group and nine in the microfracture group . The mean age ( 40 ± 9 years ) , body mass index ( BMI ) ( 28 ± 4 kg/m2 ) , duration between the first symptoms and treatment ( 3 ± 5 years ) , and lesion size ( 287 ± 138 mm2 in the NeoCart group and 252 ± 135 mm2 in the microfracture group ) were similar between the groups . Adverse event rates per procedure did not differ between the treatment arms . The scores on the Short Form-36 ( SF-36 ) , Knee Injury and Osteoarthritis Outcome Score ( KOOS ) activities of daily living ( ADL ) scale , and International Knee Documentation Committee ( IKDC ) form improved from baseline ( p < 0.05 ) to two years postoperatively in both treatment groups . In the NeoCart group , improvement , compared with baseline , was significant ( p < 0.05 ) for all measures at six , twelve , and twenty-four months . Improvement in the NeoCart group was significantly greater ( p < 0.05 ) than that in the microfracture group for the KOOS pain score at six , twelve , and twenty-four months ; the KOOS symptom score at six months ; the IKDC , KOOS sports , and visual analog scale ( VAS ) pain scores at twelve and twenty-four months ; and the KOOS quality of life ( QOL ) score at twenty-four months . Analysis of covariance ( ANCOVA ) at one year indicated that the change in the KOOS pain ( p = 0.016 ) and IKDC ( p = 0.028 ) scores from pretreatment levels favored the NeoCart group . Significantly more NeoCart-treated patients ( p = 0.0125 ) had responded to therapy ( were therapeutic responders ) at six months ( 43 % versus 25 % in the microfracture group ) and twelve months ( 76 % versus 22 % in the microfracture group ) . This trend continued , as the proportion of NeoCart-treated patients ( fifteen of nineteen ) who were therapeutic responders at twenty-four months was greater than the proportion of microfracture-treated participants ( four of nine ) who were therapeutic responders at that time . CONCLUSIONS This r and omized study suggests that the safety of autologous cartilage tissue implantation , with use of the NeoCart technique , is similar to that of microfracture surgery and is associated with greater clinical efficacy at two years after treatment BACKGROUND Osteoarthritis of the knee is commonly diagnosed and monitored with radiography . However , the reliability of radiographic classification systems for osteoarthritis and the correlation of these classifications with the actual degree of confirmed degeneration of the articular cartilage of the tibiofemoral joint have not been adequately studied . METHODS As the Multicenter ACL ( anterior cruciate ligament ) Revision Study ( MARS ) Group , we conducted a multicenter , prospect i ve longitudinal cohort study of patients undergoing revision surgery after anterior cruciate ligament reconstruction . We followed 632 patients who underwent radiographic evaluation of the knee ( an anteroposterior weight-bearing radiograph , a posteroanterior weight-bearing radiograph made with the knee in 45 ° of flexion [ Rosenberg radiograph ] , or both ) and arthroscopic evaluation of the articular surfaces .  Three blinded examiners independently grade d radiographic findings according to six commonly used systems-the Kellgren-Lawrence , International Knee Documentation Committee , Fairbank , Br and t et al. , Ahlbäck , and Jäger-Wirth classifications . Interobserver reliability was assessed with use of the intraclass correlation coefficient . The association between radiographic classification and arthroscopic findings of tibiofemoral chondral disease was assessed with use of the Spearman correlation coefficient . RESULTS Overall , 45 ° posteroanterior flexion weight-bearing radiographs had higher interobserver reliability ( intraclass correlation coefficient = 0.63 ; 95 % confidence interval , 0.61 to 0.65 ) compared with anteroposterior radiographs ( intraclass correlation coefficient = 0.55 ; 95 % confidence interval , 0.53 to 0.56 ) . Similarly , the 45 ° posteroanterior flexion weight-bearing radiographs had higher correlation with arthroscopic findings of chondral disease ( Spearman rho = 0.36 ; 95 % confidence interval , 0.32 to 0.39 ) compared with anteroposterior radiographs ( Spearman rho = 0.29 ; 95 % confidence interval , 0.26 to 0.32 ) . With respect to st and ards for the magnitude of the reliability coefficient and correlation coefficient ( Spearman rho ) , the International Knee Documentation Committee classification demonstrated the best combination of good interobserver reliability and medium correlation with arthroscopic findings . CONCLUSIONS The overall estimates with the six radiographic classification systems demonstrated moderate ( anteroposterior radiographs ) to good ( 45 ° posteroanterior flexion weight-bearing radiographs ) interobserver reliability and medium correlation with arthroscopic findings . The International Knee Documentation Committee classification assessed with use of 45 ° posteroanterior flexion weight-bearing radiographs had the most favorable combination of reliability and correlation . LEVEL OF EVIDENCE Diagnostic Level I. See Instructions for Authors for a complete description of levels of evidence BACKGROUND Matrix-induced autologous chondrocyte implantation is a technique for repairing articular cartilage defects in the knee . Despite reported improvements in pain , little is known about the recovery of knee biomechanics during walking gait . METHODS A r and omized controlled study design was used to investigate knee biomechanics during gait in 61 patients following matrix-induced autologous chondrocyte implantation , in conjunction with either ' accelerated ' or ' traditional ' approaches to post-operative weight-bearing rehabilitation .  Gait analysis was performed at 3 , 6 and 12 months post-surgery in both patient groups , and two matched , unaffected control groups for comparison . FINDINGS The spatiotemporal and ground reaction force parameters were similar between patient groups and their respective control groups at all time points . When compared with controls , both patient groups demonstrated significantly reduced knee extension moments up until , and including , 12 months . The traditional group demonstrated a significantly reduced knee adduction moment at 3 , 6 and 12 months , and a significantly reduced knee flexion moment at 3 months . There were no differences in these knee moments between the accelerated patient group and controls . INTERPRETATION Overall , a higher level of gait dysfunction was observed in patients who underwent traditional rehabilitation . Future research is needed to investigate the recovery of normal gait following matrix-induced autologous chondrocyte implantation , and its effect on repair tissue development Background : Matrix-induced autologous chondrocyte implantation ( MACI ) has become an established technique for the repair of full-thickness chondral defects in the knee , although best patient outcomes appear limited by a lack of evidence -based knowledge on how to progressively increase postoperative weightbearing ( WB ) and rehabilitation exercises . Hypothesis : To determine the safety and efficacy of an accelerated WB regimen after MACI in the tibiofemoral joint . Study Design : R and omized controlled trial ; Level of evidence , 1 . Methods : Clinical and radiological assessment s were performed in 28 knees at 12 months after MACI to the medial or lateral femoral condyle . Both rehabilitation interventions sought to protect the implant for an initial period and then incrementally increase load bearing . Under the “ accelerated ” ( AR ) protocol , patients reached full WB at 6 weeks after surgery compared with 8 weeks for what was considered to be the current “ best practice ” ( CR ) WB regimen based on previous research . Assessment s included the Knee Injury and Osteoarthritis Outcome Score ( KOOS ) , 36-Item Short Form Health Survey ( SF-36 ) , visual analog scale , 6-minute walk test , and active knee range of motion ( ROM ) .  High-resolution magnetic resonance imaging ( MRI ) was used to describe the quality and quantity of repair tissue via the assessment of pertinent parameters of graft repair as well as an MRI composite score . Results : Patients in both groups demonstrated significant improvement ( P < .05 ) in all clinical measures over the preoperative and postoperative timeline from before surgery to 12 months after surgery . The AR group reported significantly better ( P < .05 ) SF-36 physical component scores at 8 weeks and significantly greater ( P < .05 ) KOOS quality of life scores at 6 and 12 months postoperatively . Although no differences ( P > .05 ) were observed between the 2 groups for active knee ROM , the AR group did achieve full active knee extension as early as 4 weeks compared with the CR group at 12 weeks . There was no difference ( P > .05 ) in graft quality as assessed by MRI ( MOCART composite score : AR , 3.34 ; CR , 3.04 ) , with no patients suffering any adverse effects from the implant up to 12 months , regardless of the rehabilitation protocol employed . Conclusion : The AR approach that reduced the length of time spent ambulating on crutches result ed in improved general physical function and quality of life and an earlier attainment of full active knee extension when compared with the CR approach . There were no graft complications ascertained through MRI . This regimen appears safe and may potentially speed up the recovery of normal gait function . A larger patient cohort and follow-up are required to observe long-term graft outcomes Young patients with early osteoarthritis wishing to remain functionally active have limited treatment options . Existing studies examining the use of autologous chondrocyte implantation ( ACI ) have included patients with early degenerative changes ; however , none specifically investigated the outcome of ACI with this challenging problem . We prospect ively followed 153 patients ( 155 knees ) for up to 11 years after treatment with ACI for early-stage osteoarthritis . Patient pain and function was assessed using WOMAC , modified Cincinnati , SF-36 , Knee Society score , and a satisfaction question naire .  Mean patient age was 38.3 years . On average , 2.1 defects were treated per knee ; the mean defect size was 4.9 cm2 and total area per knee was 10.4 cm2 . Eight percent of joints were considered treatment failures that went on to arthroplasty and the remaining patients experienced 50 % to 75 % improvement in WOMAC subscales . Our data suggest that ACI in patients with early osteoarthritis results in clinical ly relevant reductions in pain and improvement in function . At 5 years postoperatively , 92 % of patients were functioning well and were able to delay the need for joint replacement . Given the limited number of treatment options for this subset of patients , autologous chondrocyte implantation may offer improved quality of life for young osteoarthritic patients .Level of Evidence : Level IV , case series . See Guidelines for Authors for a complete description of levels of evidence Background : Current methods used to restore the joint surface in patients with localized articular cartilage defects include transplantation of an autologous osteochondral cylinder and implantation of autologous chondrocytes . The purpose of this study was to evaluate the clinical and histological outcomes of these two techniques . Methods : We performed a prospect i ve clinical study to investigate the two-year outcomes in forty patients with an articular cartilage lesion of the femoral condyle who had been r and omly treated with either transplantation of an autologous osteochondral cylinder or implantation of autologous chondrocytes . Biopsy specimens from representative patients of both groups were evaluated with histological staining , immunohistochemistry , and scanning electron microscopy . Results : According to the postoperative Lysholm score , the recovery after autologous chondrocyte implantation was slower than that after osteochondral transplantation at six months ( p ⩽ 0.015 ) , twelve months ( p ⩽ 0.001 ) , and twenty-four months ( p ⩽ 0.012 ) . On the basis of the Meyers score and the Tegner activity score , the results were equally good with the two methods two years after treatment . Histomorphological evaluation of biopsy specimens within two years after autologous chondrocyte implantation demonstrated a complete , mechanically stable resurfacing of the defect in all patients . The tissue consisted mainly of fibrocartilage , while localized areas of hyaline-like regenerative cartilage could be detected close to the subchondral bone . Although a gap remained at the site of the transplantation in all five biopsy specimens examined as long as two years after osteochondral cylinder transplantation , histomorphological analysis and scanning electron microscopy revealed no differences between the osteochondral transplants and the surrounding original cartilage . Conclusions : Both treatments result ed in a decrease in symptoms . However , the improvement provided by the autologous chondrocyte implantation lagged behind that provided by the osteochondral cylinder transplantation . Histologically , the defects treated with autologous chondrocyte implantation were primarily filled with fibrocartilage , whereas the osteochondral cylinder transplants retained their hyaline character , although there was a persistent interface between the transplant and the surrounding original cartilage . Limitations of our study included the small number of patients , the relatively short ( two-year ) follow-up , and the absence of a control group . Level of Evidence : Therapeutic study , Level II-2 ( poor- quality r and omized controlled trial [ e.g. , < 80 % follow-up ] ) . See Instructions to Authors for a complete description of levels of evidence Background : Sexual dimorphism in humans has already been documented at different levels , and preliminary findings also suggest the importance of patient sex on clinical outcome in the treatment of cartilage lesions . Purpose : To document and analyze the influence of sex on clinical outcome in a large cohort of patients treated with a cartilage regenerative procedure for knee chondral lesions and prospect ively followed at midterm follow-up . Study Design : Cohort study ; Level of evidence , 3 . Methods : A total of 250 knees were treated with matrix-assisted autologous chondrocyte transplantation ( MACT ) and prospect ively evaluated with International Knee Documentation Committee ( IKDC ) , EuroQol visual analog scale ( EQ-VAS ) , and Tegner scores at 1- , 2- , and minimum 5-year follow-ups to compare results obtained in men and women . The lesions were focal International Cartilage Repair Society grade III-IV chondral knee defects involving femoral condyles , trochleae , and patellae . Two homogeneous groups of 56 male patients and 56 female patients were then selected by a blinded statistician for a matched-pair analysis . Results : A statistically significant improvement in all the scores in both men and women was observed in the general population . The IKDC subjective score showed better results for men at all follow-up times : at 5 years , the mean IKDC subjective score was 79.5 ± 18.6 versus 64.3 ± 20.2 for men and women , respectively ( P < .0005 ) , and the same trend was confirmed with the EQ-VAS and Tegner scores . The matched-pair analysis confirmed the difference of final results achieved ( 74.1 ± 19.8 vs 63.7 ± 20.2 , respectively ; P = .006 ) . However , men and women started with different preoperative levels , and the analysis of the improvement obtained was not significantly different . Finally , when scores were st and ardized for each patient , according to the mean score typical for the corresponding age and sex category in a healthy population , a sex-related difference was not confirmed at any of the follow-ups . Etiological factors , lesion site , and preinjury activity level differed in women and men of the general population and were the confounding factors responsible for the different outcome not confirmed by the analysis of homogeneous cohorts of patients . Conclusion : Women have a different knee chondral lesion pattern and more often have unfavorable conditions related to the cause of injury , site , and activity level , and they also have lower raw , not st and ardized , scores . However , a matched-pair analysis with data st and ardized for the specific patient categories showed that , on equal terms , women have the same possibilities for successful outcome as men after surgical treatment for knee cartilage regeneration A biodegradable , hyaluronian-based biocompatible scaffold was used for autologous chondrocyte transplantation . This prospect i ve study analyzes a clinical outcome of 70 consecutive patients treated by arthroscopic autologous chondrocyte transplantation at minimum 24 months follow up ( 47 of these patients achieved minimum 36 months follow-up and 21 patients minimum 48 months follow-up ) in order to establish clear indication criteria for this type of treatment . 31 of these patients presented isolated chondral lesions , while 39 patients with associated lesions ( 23 ACL lesions , 28 meniscal lesions , 1 varus knee ) were treated during the same surgical procedure with cartilage harvesting . A statistically significant clinical improvement was shown just at 24 months and the second-look arthroscopy demonstrated a complete coverage of the grafted area with a hyaline cartilage-like tissue in 12 of 15 analyzed patients . A better clinical outcome was observed in young , well-trained patients and in traumatic lesions . Other factors , such as defect size , localization , previous and associated surgery did not influence significantly the results . This matrix autologous chondrocyte transplantation procedure simplifies the surgical procedure and can be performed arthroscopically , thus reducing surgical morbidity and recovery time This prospect i ve six-year longitudinal study review s the clinical outcome of patients undergoing autologous chondrocyte implantation ( ACI ) and a porcine type I/III collagen membrane cover for deep chondral defects of the knee . We present 57 patients ( 31 male , 26 female ) with a mean age of 31.6 years ( range 15–51 years ) that have undergone ACI since July 1998 . The mean size of the defect was 3.14 cm2 ( range 1.0–7.0 cm2 ) . All patients were assessed annually using seven independent vali date d clinical rating scores with the data analysed using ANOVA . ACI using a porcine type I/III collagen membrane cover produced statistically significant improvements ( p < 0.001 ) , maintained for up to six years , in knee symptoms compared to pre-operative levels . This study provides evidence of the medium-term benefit achieved by transplanting autologous chondrocytes to osteochondral defects INTRODUCTION The results for autologous chondrocyte implantation ( ACI ) in the treatment of full thickness chondral defects in the knee are encouraging . At present two techniques have been described to retain the chondrocyte suspension within the defect . The first involves using a periosteal cover ( ACI-P ) and the second involves using a type I/III collagen membrane ( ACI-C ) . To the authors knowledge there are no comparative studies of these two techniques in the current literature . We have therefore undertaken such a study to establish if there is a difference between the 2 techniques based on a clinical and arthroscopic assessment . METHODS A total of 68 patients with a mean age of 30.52 years with symptomatic articular cartilage defects were r and omised to have either ACI-P ( 33 patients ) or ACI-C ( 35 patients ) . The mean defect size was 4.54 cm2 . All patients were followed up at 24 months . RESULTS A clinical and functional assessment showed that 74 % of patients had a good or excellent result following the ACI-C compared with 67 % after the ACI-P at 2 years . Arthroscopy at 1 year also demonstrated similar results for both techniques . However , 36.4 % of the ACI-P grafts required shaving for hypertrophy compared with none for the ACI-C grafts at 1 year . DISCUSSION This study has shown no statistical difference between the clinical outcome of ACI-C versus ACI-P at 2 years . A significant number of patients who had the ACI-P required shaving of a hypertrophied graft . We conclude that there is no advantage in using periosteum as a cover for retaining chondrocytes within an osteochondral defect ; as a result we advocate the use of an alternative cover such as a manufactured type I/III collagen membrane Peterson ’s pioneering experience with the first clinical application of autologous chondrocyte implantation showed improvement in clinical outcomes , durable as much as 11 years , for a difficult patient population . An assessment of the general applicability of this technology in the United States requires long-term , multicenter followup . The purpose of this multicenter cohort study was to assess the clinical outcomes of patients treated with autologous chondrocyte implantation for lesions of the distal femur .  Modified 10-point scales of the Cincinnati knee rating system were used to measure outcomes assessment s at baseline and at 5 years . Eighty-seven percent ( 87 of 100 ) of patients completed 5-year followup assessment s. Patients were an average 37 years of age , had a mean total defect size of 4.9 cm2 , and had low baseline overall condition scores . At least one prior cartilage repair procedure had failed in 70 % of the patients . At followup , 87 patients reported a mean improvement of 2.6 points in the overall condition score , including 62 with improved conditions , six with no change in condition , and 19 with worsened conditions . Of the 62 patients who improved , the mean overall condition score improved 4.1 points at followup . Patients treated with autologous chondrocyte implantation for large cartilage defects in the distal femur reported improvement in outcome scores at 5 years followup . Level of Evidence : Therapeutic study , Level II-1 ( prospect i ve cohort study ) . See the Guidelines for Authors for a complete description of levels of evidence Background The results of R and omized Controlled Trials ( RCTs ) on time-to-event outcomes that are usually reported are median time to events and Cox Hazard Ratio . These do not constitute the sufficient statistics required for meta- analysis or cost-effectiveness analysis , and their use in secondary analyses requires strong assumptions that may not have been adequately tested . In order to enhance the quality of secondary data analyses , we propose a method which derives from the published Kaplan Meier survival curves a close approximation to the original individual patient time-to-event data from which they were generated . Methods We develop an algorithm that maps from digitised curves back to KM data by finding numerical solutions to the inverted KM equations , using where available information on number of events and numbers at risk . The reproducibility and accuracy of survival probabilities , median survival times and hazard ratios based on reconstructed KM data was assessed by comparing published statistics ( survival probabilities , medians and hazard ratios ) with statistics based on repeated reconstructions by multiple observers . Results The validation exercise established there was no material systematic error and that there was a high degree of reproducibility for all statistics . Accuracy was excellent for survival probabilities and medians , for hazard ratios reasonable accuracy can only be obtained if at least numbers at risk or total number of events are reported . Conclusion The algorithm is a reliable tool for meta- analysis and cost-effectiveness analyses of RCTs reporting time-to-event data . It is recommended that all RCTs should report information on numbers at risk and total number of events alongside KM curves Early osteoarthritis ( OA ) is increasingly being recognized in patients who wish to remain active while not accepting the limitations of conservative treatment or joint replacement . The aim of this systematic review was to evaluate the existing evidence for treatment of patients with early OA using articular cartilage repair techniques . A systematic search was performed in EMBASE , MEDLINE , and the Cochrane collaboration . Articles were screened for relevance and appraised for quality . Nine articles of generally low method ological quality ( mean Coleman score 58 ) including a total of 502 patients ( mean age range = 36 - 57 years ) could be included . In the reports , both radiological and clinical criteria for early OA were applied . Of all patients included in this review , 75 % were treated with autologous chondrocyte implantation . Good short-term clinical outcome up to 9 years was shown . Failure rates varied from 8 % to 27.3 % . The conversion to total knee arthroplasty rate was 2.5 % to 6.5 % . Although a ( r and omized controlled ) trial in this patient category with long-term follow-up is needed , the literature suggests autologous chondrocyte implantation could provide good short- to mid-term clinical outcome and delay the need for total knee arthroplasty . The use of st and ardized criteria for early OA and implementation of ( r and omized ) trials with long-term follow-up may allow for further expansion of the research field in articular cartilage repair to the challenging population with ( early ) OA Objectives Matrix-assisted autologous chondrocyte transplantation ( MACT ) has been developed and applied in the clinical practice in the last decade to overcome most of the disadvantages of the first generation procedures . The purpose of this systematic review is to document and analyse the available literature on the results of MACT in the treatment of chondral and osteochondral lesions of the knee . Methods All studies published in English addressing MACT procedures were identified , including those that fulfilled the following criteria : 1 ) level I-IV evidence , 2 ) measures of functional or clinical outcome , 3 ) outcome related to cartilage lesions of the knee cartilage . Results The literature analysis showed a progressively increasing number of articles per year . A total of 51 articles were selected : three r and omised studies , ten comparative studies , 33 case series and five case reports . Several scaffolds have been developed and studied , with good results reported at short to medium follow-up . Conclusions MACT procedures are a therapeutic option for the treatment of chondral lesions that can offer a positive outcome over time for specific patient categories , but high-level studies are lacking . Systematic long-term evaluation of these techniques and r and omised controlled trials are necessary to confirm the potential of this treatment approach , especially when comparing against less ambitious traditional treatments Autologous chondrocyte implantation ( ACI ) is used widely as a treatment for  symptomatic chondral and osteochondral defects of the knee . Variations of the original periosteum-cover technique include the use of porcine-derived type I/type III collagen as a cover ( ACI-C ) and matrix-induced autologous chondrocyte implantation ( MACI ) using a collagen bilayer seeded with chondrocytes . We have performed a prospect i ve , r and omised comparison of ACI-C and MACI for the treatment of symptomatic chondral defects of the knee in 91 patients , of whom 44 received ACI-C and 47 MACI grafts .  Both treatments result ed in improvement of the clinical score after one year . The mean modified Cincinnati knee score increased by 17.6 in the ACI-C group and 19.6 in the MACI group ( p = 0.32 ) . Arthroscopic assessment s performed after one year showed a good to excellent International Cartilage Repair Society score in 79.2 % of ACI-C and 66.6 % of MACI grafts . Hyaline-like cartilage or hyaline-like cartilage with fibrocartilage was found in the biopsies of 43.9 % of the ACI-C and 36.4 % of the MACI grafts after one year . The rate of hypertrophy of the graft was 9 % ( 4 of 44 ) in the ACI-C group and 6 % ( 3 of 47 ) in the MACI group . The frequency of re-operation was 9 % in each group . We conclude that the clinical , arthroscopic and histological outcomes are comparable for both ACI-C and MACI . While MACI is technically attractive , further long-term studies are required before the technique is widely adopted Autologous chondrocyte implantation ( ACI ) and mosaicplasty are both cl aim ed to be successful for the repair of defects of the articular cartilage of the knee but there has been no comparative study of the two methods . A total of 100 patients with a mean age of 31.3 years ( 16 to 49 ) and with a symptomatic lesion of the articular cartilage in the knee which was suitable for cartilage repair was r and omised to undergo either  ACI or mosaicplasty ; 58 patients had ACI and 42 mosaicplasty .  Most lesions were post-traumatic and the mean size of the defect was 4.66 cm2 . The mean duration of symptoms was 7.2 years and the mean number of previous operations , excluding arthroscopy , was 1.5 . The mean follow-up was 19 months ( 12 to 26 ) . Functional assessment using the modified Cincinatti and Stanmore scores and objective clinical assessment showed that 88 % had excellent or good results after ACI compared with 69 % after mosaicplasty . Arthroscopy at one year demonstrated excellent or good repairs in 82 % after ACI and in 34 % after mosaicplasty . All five patellar mosaicplasties failed . Our prospect i ve , r and omised , clinical trial has shown significant superiority of ACI over mosaicplasty for the repair of articular defects in the knee . The results for ACI are comparable with those in other studies , but those for mosaicplasty suggest that its continued use is of dubious value Objective The efficacy and safety of BST-CarGel ® , a chitosan scaffold for cartilage repair was compared with microfracture alone at 1 year during a multicenter r and omized controlled trial in the knee . This report was undertaken to investigate 5-year structural and clinical outcomes . Design The international r and omized controlled trial enrolled 80 patients , aged 18 to 55 years , with grade III or IV focal lesions on the femoral condyles . Patients were r and omized to receive BST-CarGel ® treatment or microfracture alone  , and followed st and ardized 12-week rehabilitation . Co- primary endpoints of repair tissue quantity and quality were evaluated by 3-dimensional MRI quantification of the degree of lesion filling ( % ) and T2 relaxation times . Secondary endpoints were clinical benefit measured with WOMAC ( Western Ontario and McMaster Universities Osteoarthritis Index ) question naires and safety . General estimating equations were used for longitudinal statistical analysis of repeated measures . Results Blinded MRI analysis demonstrated that BST-CarGel ® -treated patients showed a significantly greater treatment effect for lesion filling ( P = 0.017 ) over 5 years compared with microfracture alone . A significantly greater treatment effect for BST-CarGel ® was also found for repair tissue T2 relaxation times ( P = 0.026 ) , which were closer to native cartilage compared to the microfracture group . BST-CarGel ® and microfracture groups showed highly significant improvement at 5 years from pretreatment baseline for each WOMAC subscale ( P < 0.0001 ) , and there were no differences between the treatment groups . Safety was comparable for both groups . Conclusions BST-CarGel ® was shown to be an effective mid-term cartilage repair treatment . At 5 years , BST-CarGel ® treatment result ed in sustained and significantly superior repair tissue quantity and quality over microfracture alone . Clinical benefit following BST-CarGel ® and microfracture treatment were highly significant over baseline levels Objective : To compare the responsiveness of six common patient-reported outcomes ( PROs ) following  autologous chondrocyte implantation ( ACI ) .  Design : A systematic search was conducted to identify reports of PROs following ACI . Study quality was evaluated using the modified Coleman Methodology Score ( mCMS ) . For each outcome score , pre- to postoperative paired Hedge ’s g effect sizes were calculated with 95 % confidence intervals ( CIs ) . R and om effects meta-analyses were performed to provide a summary response for each PRO at time points ( TP ) I ( < 1 year ) , II ( 1 year to < 2 years ) , III ( 2 years to < 4 years ) , IV ( ≥4 years ) , and overall . Results : The mean mCMS for the 42 articles included was 50.9 ± 9.2 . For all evaluated instruments , none of the mean effect size CIs encompassed zero . The International Knee Documentation Committee Subjective Knee Form ( IKDC ) had increasing responsiveness over time with TP-IV , demonstrating greater mean effect size [ confidence interval ] ( 1.78 [ 1.33 , 2.24 ] ) than TP-I ( 0.88 [ 0.69 , 1.07 ] ) . The Knee Injury and Osteoarthritis Outcome Score – Sports and recreation subscale ( KOOS-Sports ) was more responsive at TP-III ( 1.76 [ 0.87 , 2.64 ] ) and TP-IV ( 0.98 [ 0.81 , 1.15 ] ) than TP-I ( 0.61 [ 0.44 , 0.78 ] ) . Overall , the Medical Outcomes Study 36-Item Short Form Health Survey Physical Component Scale ( 0.60 [ 0.46 , 0.74 ] ) was least responsive . Both the Lysholm Scale ( 1.42 [ 1.14 , 1.72 ] ) and the IKDC ( 1.37 [ 1.13 , 1.62 ] ) appear more responsive than the KOOS-Sports ( 0.90 [ 0.73 , 1.07 ] ) . All other KOOS subscales had overall effect sizes ranging from 0.90 ( 0.74 , 1.22 ) ( Symptoms ) to 1.15 ( 0.76 , 1.54 ) ( Quality of Life ) . Conclusions : All instruments were responsive to improvements in function following ACI . The Lysholm and IKDC were the most responsive instruments across time . IKDC and KOOS-Sports may be more responsive to long-term outcomes , especially among active individuals Abstract Purpose To evaluate the long-term clinical outcome after microfracture treatment of focal chondral defects of the knee and to investigate possible early determinants of the outcome . Methods A prospect i ve cohort of 110 patients , treated with microfracture , was evaluated at a median of 12 years ( range 10–14 ) by Lysholm score , VAS of knee function and VAS of knee pain .  Pre- and perioperative information was collected , and additional surgery to the same knee during the follow-up period was recorded . Analysis of variance and paired t test were used for comparison of the long-term data to results from the baseline examination and a former 5-year ( midterm ) follow-up evaluation . Results Forty-three patients needed additional surgery to the knee including seven knee replacements . Fifty had a poor long-term outcome —defined as a knee replacement surgery or Lysholm score below 64 . A poor result was more common in subgroups with mild degenerative changes in the cartilage surrounding the treated defect , concurrent partial meniscectomy , poor baseline Lysholm score or long-st and ing knee symptoms . The Lysholm score , function VAS and pain VAS all significantly improved from the baseline values to the mean scores of 65 ( SD 24 ) , 65 ( SD 24 ) and 31 ( SD 24 ) , respectively , at the long-term evaluation . The long-term scores did not differ significantly from the midterm scores . Conclusions The outcome scores improved significantly from baseline to the long-term evaluation and were not different from the midterm outcome . Still , a normal knee function was generally not achieved , and many patients had further surgery . The results call for more research and , at present , caution in recommending microfracture in articular cartilage defects , especially in subgroups with worse prognosis . Level of evidence Case series , Level IV Background Various approaches have been proposed to treat articular cartilage lesions , which are plagued by inherent limited healing potential . Purpose To compare the clinical outcome of patients treated with second-generation autologous chondrocyte implantation implants with those treated with the microfracture repair technique at 5-year follow-up . Study Design Cohort study ; Level of evidence , 2 . Methods Eighty active patients ( mean age , 29.8 years ) and grade III to IV cartilage lesions of the femoral condyles or trochlea were treated with  arthroscopic second-generation autologous chondrocyte implantation Hyalograft C or microfracture ( 40 patients per group ) . Patients achieved a minimum 5-year follow-up and were prospect ively evaluated . Results Both groups showed statistically significant improvement of all clinical scores from preoperative interval to 5-year follow-up . There was a significant improvement for the International Knee Documentation Committee subjective score from preoperative to 5-year follow-up ( Wilcoxon test , P < .001 ) . In the microfracture group , the International Knee Documentation Committee objective score increased from 2.5 % normal and nearly normal knees before the operation to 75 % normal and nearly normal knees at 5-year follow-up , and the subjective score increased from 41.1 ± 12.3 preoperatively to 70.2 ± 14.7 at 5-year follow-up . In the group treated with Hyalograft C , the International Knee Documentation Committee objective score increased from 15 % normal and nearly normal knees before the operation to 90 % normal and nearly normal knees at 5-year follow-up , and its subjective score increased from 40.5 ± 15.2 preoperatively to 80.2 ± 19.1 at 5-year follow-up ( Wilcoxon test , P < .001 ) . When comparing the groups , better improvement of the International Knee Documentation Committee objective ( P < .001 ) and subjective ( P = .003 ) scores was observed in the Hyalograft C group at 5-year follow-up . The return to sports at 2 years was similar in both groups and remained stable after 5 years in the Hyalograft C group ; it worsened in the microfracture group . Conclusion Both methods have shown satisfactory clinical outcome at medium-term follow-up . Better clinical results and sport activity resumption were noted in the group treated with second-generation autologous chondrocyte transplantation Cartilage defects occur in approximately 12 % of the population and can result in significant function impairment and reduction in quality of life . Evidence for the variety of surgical treatments available is inconclusive . This study aim ed to compare the clinical outcomes of patients with symptomatic cartilage defects treated with matrix-induced autologous chondrocyte implantation ( MACI ™ or microfracture ( MF ) . Included patients were ≥18 and ≤50 years of age with symptomatic , post-traumatic , single , isolated chondral defects ( 4–10 cm2 ) and were r and omised to receive MACI ™ or MF .  Patients were followed up 8–12 , 22–26 and 50–54 weeks post-operatively for efficacy and safety evaluation . Outcome measures were the Tegner , Lysholm and ICRS scores . Sixty patients were included in a r and omised study ( 40 MACI ™ , 20 MF ) . The difference between baseline and 24 months post-operatively for both treatment groups was significant for the Lysholm , Tegner , patient ICRS and surgeon ICRS scores ( all P < 0.0001 ) . However , MACI ™ was significantly more effective over time ( 24 months versus baseline ) than MF according to the Lysholm ( P = 0.005 ) , Tegner ( P = 0.04 ) , ICRS patient ( P = 0.03 ) and ICRS surgeon ( P = 0.02 ) scores . There were no safety issues related to MACI ™ or MF during the study . MACI ™ is superior to MF in the treatment of articular defects over 2 years . MACI ™ and MF are complementary procedures , depending on the size of the defect and symptom recurrence . The MACI ™ technique represents a significant advance over both first and second generation chondrocyte-based cartilage repair techniques for surgeons , patients , health care institutions and payers in terms of reproducibility , safety , intraoperative time , surgical simplicity and reduced invasiveness Abstract Purpose Microfracture is a well-established treatment procedure for chondral defects in high-dem and population with good short-term results . The purpose of our study was to evaluate long-term clinical outcome of microfracture treatment in athletes with full-thickness chondral defects . Methods Between 1991 and 2001 , 170 patients were treated with microfracture for full-thickness knee chondral lesions at our institute and 67 of them were included in this study and prospect ively followed up . Sixty-one athletes ( 91 % ) were available at final follow-up ( average 15.1 years ) . Average lesion size was 401 ± 27 mm2 . Lysholm , Tegner and International Knee Documentation Committee ( IKDC ) ( subjective– objective ) scores were utilized pre-operatively and at 2-year , 5-year and final follow-up ; Knee injury and Osteoarthritis Outcome Score ( KOOS ) , visual analog scale ( VAS ) and Marx scores were also collected at final follow-up . Results IKDC , Lysholm and Tegner scores increased significantly at 2 years , but gradually deteriorated at long term ; however , average scores were significantly above baseline at final follow-up . Seven patients ( 11 % ) were considered as failures as they underwent another operation because of reinjury or persistent pain during the first 5 years . Pain and swelling during strenuous activities was reported only in nine patients by the end of 2 years and in 35 patients at final follow-up . Patients with smaller lesions ( ≤400 mm² ) and younger patients ( ≤30 years ) showed significantly better results in KOOS , VAS and Marx scores . Radiographs performed at final follow-up showed evidence of progression of osteoarthritis changes in 40 % of the knees , with higher rate in older patients with large or multiple lesions ( p < 0.05 ) . Conclusions Microfracture when applied in young patients with smaller lesions can offer good clinical results at short- and long-term follow-up ; lesion size is more important prognostic factor of outcome than age . Deterioration of the clinical outcome should be expected after 2 and 5 years post-treatment , and degenerative changes are present at long-term follow-up , with higher rate in older athletes with large , multiple lesions . Level of evidence IV OBJECTIVES Chondral defects of the knee cartilage are prevalent . Autologous chondrocyte implantation ( ACI ) and mosaicplasty are increasingly used to treat symptomatic knee defects . This study assessed the costs and health status outcomes after ACI and mosaicplasty . METHODS Patients were eligible to participate in this cross-sectional study if they received ACI or mosaicplasty at the Royal National Orthopaedic Hospital between 1997 and 2001 or were on a waiting list for ACI . Secondary -care re source use was collected to 2 years postoperatively using a re source collection proforma . Participants responded to postal questions about sociodemographic characteristics and knee-related ( Modified Cincinnati Knee Rating System ) and general health status ( EQ-5D ) . RESULTS Fifty-three ACI , twenty mosaicplasty , and twenty-two patients waiting for ACI participated . The average cost per patient was higher for ACI ( 10,600 pounds sterling : 95 percent confidence interval [ CI ] , 10,036 pounds sterling-11,214 pounds sterling ) than mosaicplasty ( 7,948 pounds sterling : 95 percent CI , 6,957 pounds sterling-9,243 pounds sterling ) . Postoperatively , ACI and mosaicplasty patients ( combined ) experienced better health status than those waiting for ACI . ACI patients tended to have better health status outcomes than mosaicplasty patients ( not statistically significant ) . Estimated average EQ-5D social tariff improvements for quality -adjusted life year ( QALY ) calculations were 0.23 ( ACI ) and 0.06 ( mosaicplasty ) . Average costs per QALY were 23,043 pounds sterling ( ACI ) and 66,233 pounds sterling ( mosaicplasty ) . The incremental cost effectiveness ratio ( ICER ) for providing ACI over mosaicplasty was 16,349 pounds sterling . CONCLUSIONS Average costs were higher for ACI than mosaicplasty . However , both the estimated cost per QALY and ICER for providing ACI over mosaicplasty fell beneath an implicit English funding threshold of 30,000 pounds sterling per QALY . Prospect i ve studies should include measures of utility to confirm the estimated cost utility ratios of ACI and mosaicplasty Background : Various techniques have proven to be effective for treating articular cartilage defect ( ACD ) and osteochondral defect ( OCD ) of the knee joint , but knowledge regarding which method is best still remains uncertain . Purpose : To evaluate and compare the outcomes of mosaic-type osteochondral autologous transplantation ( OAT ) and microfracture ( MF ) procedures for the treatment of articular cartilage defects of the knee joint in young active athletes . This article represents an up date of the clinical results at 10 years . Study Design : R and omized controlled trial ; Level of evidence , 1 . Methods : Between 1998 and 2002 , a total of 60 athletes with a mean age of 24.3 years ( range , 15 - 40 years ) and with a symptomatic ACD or OCD in the knee were r and omized to undergo either OAT or MF . Patients were then evaluated postoperatively using the International Cartilage Repair Society ( ICRS ) score , Tegner activity score , radiographs , and magnetic resonance imaging . The mean follow-up time was 10.4 years ( range , 9 - 11 years ) . Results : Three to 10 years after the OAT and MF procedures , patients had lower ICRS and Tegner scores ( P < .05 ) , but both groups still had significant clinical improvement over presurgery scores according to ICRS scores at 10-year follow-up . Statistically significantly better results were detected in patients in the OAT group compared with those in the MF group at 10 years ( P < .005 ) . At 10-year follow-up , there were 15 failures ( 26 % ) , including 4 failures ( 14 % ) of the OAT and 11 failures ( 38 % ) of MF treatment ( P < .05 ) . Seven patients ( 25 % ) from the OAT group and 14 patients ( 48 % ) from the MF group had radiographic evidence of Kellgren-Lawrence grade I osteoarthritis at 10 years , but these differences were not significant ( P = .083 ) or related to the clinical results . The ICRS and Tegner scores of younger athletes ( < 25 years at the time of primary surgery ) remained significantly higher after 10 years compared with older patients ( P < .05 ) ; 15 of 20 patients ( 75 % ) in the OAT group and 8 of 22 patients ( 37 % ) in the MF group maintained the same physical activity level . Conclusion : The OAT technique for ACD or OCD repair in the athletic population allows for a higher rate of return to and maintenance of sports at the preinjury level compared with MF BACKGROUND There is limited information regarding direct comparisons of the outcome of osteochondral autograft transfer ( OAT ) mosaicplasty and microfracture for the treatment of isolated articular cartilage defects of the knee . The purpose of this retrospective comparative study was to compare the general health outcomes , knee function , and Marx Activity Rating Scale scores for patients treated with OAT or microfracture for symptomatic chondral defects of the femoral condyles or trochlea . We hypothesized that the patients in the two treatment groups would have similar clinical outcomes at intermediate-term follow-up . METHODS Ninety-six patients with full-thickness cartilage defects of the femoral condyles or trochlea were treated with either OAT mosaicplasty ( n = 48 ) or microfracture ( n = 48 ) . The average age of the patients ( thirty-two male and sixteen female in each group ) at the time of surgery was 29.7 years in the OAT group and 32.5 years in the microfracture group . Patients were prospect ively evaluated at baseline and at one , two , three , and five years postoperatively with use of vali date d clinical outcome measures including the Short Form-36 ( SF-36 ) physical component , International Knee Documentation Committee ( IKDC ) , Knee Outcome Survey activities of daily living , and Marx Activity Rating Scale instruments . Comparisons between outcomes before and after treatment or between outcomes after microfracture and mosaicplasty were made with use of two-tailed tests . RESULTS At the time of the latest follow-up , both groups demonstrated significant increases in SF-36 physical component , Knee Outcome Survey activities of daily living , and IKDC scores compared with baseline . These scores did not differ significantly between the two groups at any of the follow-up time points . However , the OAT group demonstrated a significantly greater improvement in the Marx Activity Rating Scale scores from baseline to the two-year ( p = 0.001 ) , three-year ( p = 0.03 ) , and five-year ( p = 0.02 ) time points compared with the microfracture group . CONCLUSIONS In the present retrospective comparative study , the hypothesis that patients treated with microfracture or OAT mosaicplasty for symptomatic articular cartilage defects of the femoral condyles or trochlea would have similar clinical outcomes at intermediate-term follow-up was affirmed for general health outcome and for knee function . However , patients treated with OAT mosaicplasty maintained a superior level of athletic activity compared with those treated with microfracture OBJECTIVE To investigate the relationship between anxiety and depression and reporting of knee pain in the community . METHODS Subjects ( n = 374 ) were community volunteers aged 40 years and above who are participants in the Baltimore Longitudinal Study of Aging , a prospect i ve multidisciplinary research study of normative aging . Knee pain was defined by the First National Health and Nutrition Examination Survey question " have you ever had pain in or around your knee on most days for at least one month ? " ; anxiety and depression were measured by the relevant subscales of the Arthritis Impact Measurement Scales question naire . All subjects had st and ing anteroposterior radiographs  , read for Kellgren and Lawrence ( K + L ) grade . RESULTS After adjustment for age , women reporting " ever " knee pain had significantly higher anxiety scores than those reporting " never " pain ( 3.06 + /- 0.26 versus 2.35 + /- 0.17 ; P = 0.025 ) . Pain reporting was related neither to anxiety scores in men , nor to depression in either sex . Analysis stratified by radiographic severity , adjusted for age and gender , showed that differences in anxiety were confined to those reporting knee pain in the absence of radiographic change ( i.e. , K + L grade 0 ) . CONCLUSIONS In the community , women reporting knee pain in the absence of radiographic osteoarthritis have higher anxiety scores than those without pain . Depression was not significantly related to knee pain in this population . Psychosocial factors may explain some of the discrepancy between reported knee pain and structural change as seen on x-ray Abstract Aim of the study : To compare outcomes of surgical treatment of deep cartilage defects of the knee in a group of patients treated by autologous chondrograft transplantation versus patients treated by abrasive techniques .  Material s and methods : An original method of chondrograft preparation based on cultivated autologous chondrocytes in a three-dimensional carrier-fibrin glue ( Tissucol , Baxter , Austria ) has been described . Pre clinical tests in human cadavres and porcine models have established the possibility of chondrograft use in humans . Of the 50 patients included in the study , 25 patients ( 50 % ) underwent autologous chondrograft transplantation ( group I ) and 25 patients ( 50 % ) were treated using abrasive techniques according to Johnson ( group II ) . These two groups were similar with respect to age , size of defect , depth and localization , and presence of concomitant knee injuries . The Lysholm knee and IKDC ( International Knee Documentation Committee ) subjective scores were used to evaluate the results . Results : The preoperative value of the Lysholm knee score for patients in group I was 47.60 points ; 5 months after surgery 77.20 points ; and 12 months after surgery 86.48 points . The values for the Lysholm knee score for patients in group II preoperatively , 5 months postop , and 12 months postop were 52.60 , 69.20 , and 74.48 respectively . Results 12 months after surgery were significantly better in group I as compared to group II ( p < 0.001 ) . The preoperative value of the IKDC subjective score in group I was 41.28 points ; 5 months after surgery 67.00 points ; and 12 months after surgery 76.48 points . The values for the IKDC subjective score in group II preoperatively , 5 months postop , and 12 months postop were 45.00 , 62.28 , and 68.08 respectively . Results 12 months after surgery were significantly better in group I when compared to group II ( p < 0.05 ) . Conclusions : The results obtained in this study have confirmed the better outcome in patients treated with autologous chondrograft transplantation . This original method was found to be just as effective as abrasive techniques . We recommend its use in clinical practice Background : Characterized chondrocyte implantation ( CCI ) results in significantly better early structural tissue regeneration than microfracture ( MF ) , and CCI has a midterm clinical benefit over microfracture . Purpose : This study was undertaken to evaluate the 5-year clinical outcome of CCI in a r and omized comparison with MF for the treatment of symptomatic cartilage defects of the femoral condyles of the knee . Study Design : R and omized controlled trial ; Level of evidence , 1 . Methods : Participants aged 18 to 50 years with a symptomatic isolated International Cartilage Repair Society ( ICRS ) grade III or IV cartilage lesion of the femoral condyles between 1 and 5 cm2 were r and omized to either  CCI or MF .  Clinical outcomes were measured up to 60 months after surgery using the Knee Injury and Osteoarthritis Outcome Score ( KOOS ) . The main outcome parameter was change from baseline in overall KOOS ( oKOOS ) . Adverse events were monitored . Results : Fifty-one participants were treated with CCI and 61 with MF . On average , clinical benefit was maintained through the 60-month follow-up period . The average change from baseline in oKOOS was not different between both groups ( least squares [ LS ] mean ± st and ard error [ SE ] 18.84 ± 3.58 for CCI vs 13.21 ± 5.63 for MF ; P = .116 ) . Treatment failures were comparable ( n = 7 in CCI vs n = 10 in MF ) , although MF failures tended to occur earlier . Subgroup analysis revealed that CCI result ed in better outcome in participants with time since symptom onset of less than 3 years , which was statistically significant and clinical ly relevant ( change in oKOOS <3 years mean ± SE 25.96 ± 3.45 for CCI vs 15.28 ± 3.17 for MF ; P = .026 vs oKOOS > 3 years mean ± SE 13.09 ± 4.78 for CCI vs 17.02 ± 4.50 for MF , P = .554 ) . Other subgroup analyses such as age ( cutoff 35 years ) did not show a difference . Female patients showed more failures irrespective of treatment . Conclusion : At 5 years after treatment , clinical outcomes for CCI and MF were comparable . In the early treatment group , CCI obtained statistically significant and clinical ly relevant better results than MF . Delayed treatment result ed in less predictable outcomes for CCI . These results provide strong evidence that time since onset of symptoms is an essential variable that should be taken into account in future treatment algorithms for  cartilage repair  of the knee Background : R and omized controlled trials study ing the efficacy and safety of matrix-applied characterized autologous cultured chondrocytes ( MACI ) versus microfracture ( MFX ) for treating cartilage defects are limited . Purpose : To compare the clinical efficacy and safety of MACI versus MFX in the treatment of patients with symptomatic cartilage defects of the knee . Study Design : R and omized controlled clinical trial ; Level of evidence , 1 . Methods : Patients enrolled in the SUMMIT ( Demonstrate the Superiority of MACI implant to Microfracture Treatment )  trial had ≥1 symptomatic focal cartilage defect ( Outerbridge grade III or IV ; ≥3 cm2 ) of the femoral condyles or trochlea , with a baseline Knee Injury and Osteoarthritis Outcome Score ( KOOS ) pain value < 55 . The co– primary efficacy endpoint was the change in the KOOS pain and function subscores from baseline to 2 years . Histological evaluation and magnetic resonance imaging ( MRI ) assessment s of structural repair tissue , treatment failure , the remaining 3 KOOS subscales , and safety were also assessed . Results : Of the 144 patients treated , 137 ( 95 % ) completed the 2-year assessment . Patients had a mean age of 33.8 years and a mean lesion size of 4.8 cm2 .  The mean KOOS pain and function subscores from baseline to 2 years were significantly more improved with MACI than with MFX ( pain : MACI , 37.0 to 82.5 vs MFX , 35.5 to 70.9 ; function : MACI , 14.9 to 60.9 vs MFX , 12.6 to 48.7 ; P = .001 ) . A significant improvement in scores was also observed on the KOOS subscales of activities of daily living ( MACI , 43.5 to 87.2 vs MFX , 42.6 to 75.8 ; P < .001 ) , knee-related quality of life ( MACI , 18.8 to 56.2 vs MFX , 17.2 to 47.3 ; P = .029 ) , and other symptoms ( MACI , 48.3 to 83.7 vs MFX , 44.4 to 72.2 ; P < .001 ) for patients treated with MACI compared with MFX . Repair tissue quality was good as assessed by histology/MRI , but no difference was shown between treatments . A low number of treatment failures ( nonresponders : MACI , 12.5 % vs MFX , 31.9 % ; P = .016 ) and no unexpected safety findings were reported . Conclusion : The treatment of symptomatic cartilage knee defects ≥3 cm2 in size using MACI was clinical ly and statistically significantly better than with MFX , with similar structural repair tissue and safety , in this heterogeneous patient population . Moreover , MACI offers a more efficacious alternative than MFX with a similar safety profile for the treatment of symptomatic articular cartilage defects of the knee Background Damaged articular cartilage has limited capacity for self-repair . Autologous chondrocyte implantation using a characterized cell therapy product results in significantly better early structural repair as compared with microfracture in patients with symptomatic joint surface defects of the femoral condyles of the knee . Purpose To evaluate clinical outcome at 36 months after characterized chondrocyte implantation ( CCI ) versus microfracture ( MF ) . Study Design R and omized controlled trial ; Level of evidence , 1 . Methods Patients aged 18 to 50 years with single International Cartilage Repair Society ( ICRS ) grade III/IV symptomatic cartilage defects of the femoral condyles were r and omized to CCI ( n = 57 ) or MF ( n = 61 ) . Clinical outcome was measured over 36 months by the Knee injury and Osteoarthritis Outcome Score ( KOOS ) . Serial magnetic resonance imaging ( MRI ) scans were scored using the Magnetic resonance Observation of Cartilage Repair Tissue ( MOCART ) system and 9 additional items . Gene expression profile scores associated with ectopic cartilage formation were determined by RT-PCR . Results Baseline mean overall KOOS ( ±SE ) was comparable between the CCI and MF groups ( 56.30 ± 1.91 vs 59.46 ± 1.98 , respectively ) . Mean improvement ( ±SE ) from baseline to 36 months in overall KOOS was greater in the CCI group than the MF group ( 21.25 ± 3.60 vs 15.83 ± 3.48 , respectively ) , while in a mixed linear model analysis with time as a categorical variable , significant differences favoring CCI were shown in overall KOOS ( P = .048 ) and the subdomains of Pain ( P = .044 ) and QoL ( P = .036 ) . More CCI- than MF-treated patients were treatment responders ( 83 % vs 62 % , respectively ) . In patients with symptom onset of < 2 years , the mean improvement ( ±SE ) from baseline to 36 months in overall KOOS was greater with CCI than MF ( 24.98 ± 4.34 vs 16.50 ± 3.99 , respectively ) and even greater in patients with symptom onset of <3 years ( 26.08 ± 4.10 vs 17.09 ± 3.77 , respectively ) . Characterized chondrocyte implantation patients with high ( > 2 ) versus low ( < 2 ) gene profile scores showed greater improvement from baseline in mean overall KOOS ( ±SE ) at 36 months ( 28.91 ± 5.69 vs 18.18 ± 5.08 , respectively ) . Subchondral bone reaction significantly worsened over time with MF compared with CCI ( P < .05 ) . Conclusion Characterized chondrocyte implantation for the treatment of articular cartilage defects of the femoral condyles of the knee results in significantly better clinical outcome at 36 months in a r and omized trial compared with MF . Time to treatment and chondrocyte quality were shown to affect outcome Background : While structured postoperative rehabilitation after matrix-induced autologous chondrocyte implantation ( MACI ) is considered critical , very little has been made available on how best to progressively increase weightbearing and exercise after surgery . Hypothesis : A significant improvement will exist in clinical and magnetic resonance imaging (MRI)–based scoring measures to 5 years after surgery . Furthermore , there will be no significant differences in outcomes in MACI patients at 5 years when comparing a traditional and an accelerated postoperative weightbearing regimen . Finally , patient demographics , cartilage defect parameters , and injury/surgery history will be associated with graft outcome . Study Design : R and omized controlled trial ; Level of evidence , 1 . Methods : Clinical and radiological outcomes were studied in 70 patients who underwent MACI to the medial or lateral femoral condyle , in conjunction with either an “ accelerated ” or a “ traditional ” approach to postoperative weightbearing rehabilitation .  Under the accelerated protocol , patients reached full weightbearing at 8 weeks after surgery , compared with 11 weeks for the traditional group . Clinical measures ( Knee Injury and Osteoarthritis Outcome Score [ KOOS ] , Short-Form Health Survey [ SF-36 ] , visual analog scale [ VAS ] , 6-minute walk test , and knee range of motion ) were assessed before surgery and at 3 , 6 , 12 , and 24 months and 5 years after surgery . High-resolution MRI was undertaken at 3 , 12 , and 24 months and 5 years after surgery and assessed 8 previously defined pertinent parameters of graft repair as well as a combined MRI composite score . The association between clinical and MRI-based outcomes , patient demographics , chondral defect parameters , and injury/surgery history was investigated . Results : Of the 70 patients recruited , 63 ( 31 accelerated , 32 traditional ) underwent clinical follow-up at 5 years ; 58 ( 29 accelerated , 29 traditional ) also underwent radiological assessment . A significant time effect ( P < .05 ) was demonstrated for all clinical and MRI-based scores over the 5-year period . While the VAS demonstrated significantly less frequent pain at 5 years in the accelerated group , there were no other significant differences between the 2 groups . Between 24 months and 5 years , a significant improvement ( P < .05 ) in both groups was observed for the sport and recreation subscale of the KOOS as well as a significant decrease ( P < .05 ) in active knee extension for the traditional group . There were no significant differences ( P > .05 ) in the MRI-based scores between 24 months and 5 years after surgery . Patient age and defect size exhibited significant negative correlations ( P < .05 ) with several MRI-based outcomes at 5 years , while there were no significant correlations ( P > .05 ) between clinical and MRI-based outcomes . At 5 years after surgery , 94 % and 95 % were satisfied with the ability of MACI to relieve their knee pain and improve their ability to undertake daily activities , respectively . Conclusion : The outcomes of this r and omized trial demonstrate a safe and effective accelerated rehabilitation protocol as well as a regimen that provides comparable , if not superior , clinical outcomes to patients throughout the postoperative timeline PURPOSE To compare the concomitant treatment of articular cartilage damage in the medial femoral condyle with osteochondral autologous transplantation ( OAT ) , microfracture , or debridement procedures at the time of  anterior cruciate ligament ( ACL ) reconstruction . METHODS Between 2006 and 2009 , 102 patients with a mean age of 34.1 years and with an ACL rupture and articular cartilage damage in the medial femoral condyle of the knee were r and omized to undergo OAT , microfractures , or debridement at the time of ACL reconstruction . A matched control group was included , comprising 34 patients with intact articular cartilage at the time of ACL reconstruction . There were 34 patients in the OAT-ACL group , 34 in the microfracture (MF)-ACL group , 34 in the debridement (D)-ACL group , and 34 in the control group with intact articular cartilage ( IAC-ACL group ) . The mean time from ACL injury to operation was 19.32 ± 3.43 months , and the mean follow-up was 36.1 months ( range , 34 to 37 months ) . Patients were evaluated with the International Knee Documentation Committee ( IKDC ) score , Tegner activity score , and clinical assessment . RESULTS Of 102 patients , 97 ( 95 % ) were available for the final follow-up . According to the subjective IKDC score , all 4 groups fared significantly better at the 3-year follow-up than preoperatively ( P < .005 ) . The OAT-ACL group 's IKDC subjective knee evaluation was significantly better than that of the MF-ACL group ( P = .024 ) and D-ACL group ( P = .018 ) . However , the IKDC subjective score of the IAC-ACL group was significantly better than the OAT-ACL group 's IKDC evaluation ( P = .043 ) . There was no significant difference between the MF-ACL and D-ACL  groups ' IKDC subjective scores ( P = .058 ) . Evaluation of manual pivot-shift knee laxity according to the IKDC knee examination form showed similar findings for the 4 groups immediately postoperatively and at 3-year follow-up , and the findings were rated as normal or nearly normal ( IKDC grade A or B ) in 29 of 33 patients ( 88 % ) in the OAT-ACL group , 28 of 32 patients ( 88 % ) in the MF-ACL group , 27 of 32 patients ( 84 % ) in the D-ACL group , and 31 of 34 patients ( 91 % ) in the IAC-ACL group . CONCLUSIONS Our study shows that intact articular cartilage during ACL reconstruction yields more favorable IKDC subjective scores compared with any other articular cartilage surgery type . However , if an articular defect is present , the subjective IKDC scores are significantly better for OAT versus microfracture or debridement after a mean period of 3 years . Anterior knee stability results were not significantly affected by the different articular cartilage treatment methods . LEVEL OF EVIDENCE Level II , prospect i ve comparative study BACKGROUND The optimal treatment for cartilage lesions has not yet been established . The objective of this r and omized trial was to compare autologous chondrocyte implantation with microfracture . This paper represents an up date , with presentation of the clinical results at five years . METHODS Eighty patients who had a single chronic symptomatic cartilage defect on the femoral condyle in a stable knee without general osteoarthritis were included in the study . Forty patients were treated with autologous chondrocyte implantation , and forty were treated with microfracture .  We used the International Cartilage Repair Society , Lysholm , Short Form-36 , and Tegner forms to collect clinical data , and radiographs were evaluated with use of the Kellgren and Lawrence grading system . RESULTS At two and five years , both groups had significant clinical improvement compared with the preoperative status . At the five-year follow-up interval , there were nine failures ( 23 % ) in both groups compared with two failures of the autologous chondrocyte implantation and one failure of the  microfracture  treatment at two years . Younger patients did better in both groups . We did not find a correlation between histological quality and clinical outcome . However , none of the patients with the best- quality cartilage ( predominantly hyaline ) at the two-year mark had a later failure . One-third of the patients in both groups had radiographic evidence of early osteoarthritis at five years . CONCLUSIONS Both methods provided satisfactory results in 77 % of the patients at five years . There was no significant difference in the clinical and radiographic results between the two treatment groups and no correlation between the histological findings and the clinical outcome . One-third of the patients had early radiographic signs of osteoarthritis five years after the surgery . Further long-term follow-up is needed to determine if one method is better than the other and to study the progression of osteoarthritis Objective : To compare the respective performance and effectiveness of autologous chondrocyte implantation ( ACI ) and mosaicplasty at resurfacing local full-thickness chondral defects of the knee . Design : R and omized clinical trial . Setting : Multicenter trial at orthopedic clinics and university hospitals conducted from 1997 to 2000 . Patients : A population of patients selected according to eligibility criteria of age , traumatic origin of the defect , its localization , size , and gravity , and above all , no previous surgical treatment of the lesion . Forty-seven patients were r and omly assigned to ACI or mosaicplasty  and subjected to arthroscopic debridement of the lesion at the time of enrollment . They were called for surgery 6 months after the initial debridement . Main Outcome : Improved knee functionality as assessed by repeated clinical evaluation based on the International Knee Documentation Committee Scale and the Lysholm Knee Scoring Scale . Results : Fourteen patients ( 31.8 % ) experienced substantial improvement following the initial debridement and , being clinical ly cured , received no further treatment . Seven patients ( 15.9 % ) were lost to follow-up . Among the 23 patients ( 52.3 % ) who could effectively be evaluated , a complete recovery ( ie , Lysholm Knee Scoring Scale score , 90 - 100 ) was observed upon clinical examination in 88 % of the mosaicplasty-treated patients and in 68 % of the ACI-treated ones ( P = 0.093 ) . Conclusions : Although the low power of our study prevents definitive conclusions , ACI and mosaicplasty are cartilage repair techniques that are clinical ly equivalent and similar in performance . The high percentage of spontaneous improvement ( ⅓ of the patients ) observed after simple debridement calls into question the need for prompt surgical treatment of patients with lesions similar to those included in this clinical trial . Moreover , this finding warrants further investigation , ideally through r and omized clinical trials in which patients subjected to debridement alone are compared with patients undergoing reconstructive surgery Arthroscopy and washout of the knee is commonly performed for early osteoarthritis . Very little information exists regarding long-term prognosis , especially in terms of avoidance of further surgery . Using a prospect ively gathered data base , 100 consecutive patients having knee arthroscopy with a finding of OA between 1991 and 1993 were identified and their outcome at 5 years ascertained . Ninety-nine patients with 100 arthroscoped knees were identified . Fifty-eight had isolated medial compartment disease and six had isolated lateral compartment disease . In 36 , both compartments were affected . Eighteen knees had further major surgery during follow up ; 11 had total knee replacement , four had high tibial osteotomy and three had unicondylar knee arthroplasty . Those requiring surgery were significantly older ( 62 cf . 53 years , P=0.008 ) . Meniscectomy was not an important risk factor ( chi2 , P=0.67 ) . The rate of knee survival without operation at 5 years was much lower in those aged over 60 years than in those younger ( 68 % cf . 89 % ) . ( chi2 , P=0.02 ) . Only 18 % of patients progress to major knee surgery within 5 years of arthroscopic washout for osteoarthritis . Age greater than 60 years worsens the prognosis considerably INTRODUCTION The treatment of full-thickness cartilage defects still represents a problem that has not yet been solved satisfactorily . Current methods used to cover defects in the knee joint are osteochondral cylinder transplantation ( OCT ) and autologous chondrocyte transplantation ( ACT ) . METHODS With a prospect i ve clinical investigation , at the time being with 2-year results , we have examined ACT in comparison to OCT in 20 patients with regard to clinical and histomorphological ( histology , immunohistochemistry , RES ) outcome . RESULTS We found equally good results with both methods in Lysholm , Meyers and Tegner Activity Scores . Histomorphologic evaluation of biopsies obtained by arthroscopy after ACT showed a defect filling in all cases , mainly with fibrous cartilage , while localized areas of hyalinelike regenerative cartilage were documented near the base . We did not see any histomorphologically visible change in the transplants after OCT . CONCLUSION At the time we prefer OCT instead of ACT given the correct indication We compared the results of microfracture in single versus multiple symptomatic articular cartilage defects in the knee in 110 patients with a median age of 38 years ( range 15–60 ) . Cases of reoperation of the cartilage defect were classified as failures . Clinical outcome in non-failures was evaluated by the Lysholm score and grading of knee pain and function of the knee by the use of patient-administered visual analog scales ( VAS ; 0–100 ) . Data were prospect ively collected before the operation and at the 2- to 9-year follow-up . The single lesion or the largest of multiple lesions were located on the medial femoral condyle ( n = 62 ) , trochlea ( n = 18 ) , lateral tibia ( n = 11 ) , patella ( n = 10 ) or lateral femoral condyle ( n = 9 ) . We treated one ( n = 76 ) , two ( n = 27 ) or three ( n = 7 ) lesions with a median total area of 4 cm2 ( range 1–15 ) . A total of 24 failures ( 22 % ) were registered—18 % in the single-defect subgroup and 29 % in the multiple-defects subgroup . In the remaining group of patients ( n = 86 ) , the mean Lysholm score , mean pain-score ( 0 = no pain ; 100 = worst possible pain ) and mean function-score ( 0 = useless ; 100 = full function ) improved from 51 , 52 and 41 , respectively , to 71 ( P < 0.001 ) , 30 ( P < 0.001 ) and 69 ( P < 0.001 ) at the follow-up . The pain-score was significant lower ( P = 0.042 ) , and the function-score significantly higher ( P = 0.001 ) in the group of patients with a single lesion compared to the group with 2 or 3 lesions . The Lysholm score did not differ significantly between the two subgroups ( P = 0.06 ) BACKGROUND Many patients report symptomatic relief after undergoing  arthroscopy of the knee  for osteoarthritis , but it is unclear how the procedure achieves this result . We conducted a r and omized , placebo-controlled trial to evaluate the efficacy of arthroscopy for osteoarthritis of the knee . METHODS A total of 180 patients with osteoarthritis of the knee were r and omly assigned to receive arthroscopic débridement , arthroscopic lavage , or placebo surgery . Patients in the placebo group received skin incisions and underwent a simulated débridement without insertion of the arthroscope . Patients and assessors of outcome were blinded to the treatment-group assignment . Outcomes were assessed at multiple points over a 24-month period with the use of five self-reported scores -- three on scales for pain and two on scales for function-- and one objective test of walking and stair climbing .  A total of 165 patients completed the trial . RESULTS At no point did either of the intervention groups report less pain or better function than the placebo group . For example , mean ( + /-SD ) scores on the Knee-Specific Pain Scale ( range , 0 to 100 , with higher scores indicating more severe pain ) were similar in the placebo , lavage , and débridement groups : 48.9+/-21.9 , 54.8+/-19.8 , and 51.7+/-22.4 , respectively , at one year ( P=0.14 for the comparison between placebo and lavage ; P=0.51 for the comparison between placebo and débridement ) and 51.6+/-23.7 , 53.7+/-23.7 , and 51.4+/-23.2 , respectively , at two years ( P=0.64 and P=0.96 , respectively ) . Furthermore , the 95 percent confidence intervals for the differences between the placebo group and the intervention groups exclude any clinical ly meaningful difference . CONCLUSIONS In this controlled trial involving patients with osteoarthritis of the knee , the outcomes after arthroscopic lavage or arthroscopic débridement were no better than those after a placebo procedure OBJECTIVE The purpose of this study was to use the Kellgren-Lawrence , Ahlback , and Br and t grading scales to correlate radiographic grade of osteoarthritis with the actual degree of articular cartilage degeneration within the tibiofemoral joint in patients with chronic knee pain . SUBJECTS AND METHODS The study group consisted of 125 patients with symptomatic osteoarthritis of the tibiofemoral joint . For all patients , st and ing anteroposterior radiographs of the knee were obtained before arthroscopic knee surgery . Each articular surface of the tibiofemoral joint was grade d at arthroscopy . Two radiologists retrospectively review ed the knee radiographs without knowledge of the arthroscopic findings to determine the presence and severity of osteoarthritis of the tibiofemoral joint using the Kellgren-Lawrence , Ahlback , and Br and t grading scales . Correlation coefficients describing the relation between grade of osteoarthritis and severity of articular cartilage degeneration were calculated for each grading scale . RESULTS The correlation coefficients for the Kellgren-Lawrence , Ahlback , and Br and t grading scales were 0.49 , 0.41 , and 0.56 , respectively . The differences between the correlation coefficients for the Kellgren-Lawrence and Ahlback grading scales and the correlation coefficients for the Br and t and Ahlback grading scales were statistically significant ( p < 0.05 ) . Many patients with no radiographic findings of osteoarthritis had significant articular cartilage degeneration within the tibiofemoral joint . CONCLUSION The Kellgren-Lawrence and Br and t grading scales were equally effective in defining the presence of and estimating the severity of osteoarthritis of the tibiofemoral joint but had only a moderately strong correlation with the actual degree of articular cartilage degeneration In a prospect i ve r and omised trial 76 knees with isolated degenerative changes in the medial femoral condyle of grade s 3 or 4 were treated by either arthroscopic debridement ( 40 ) or washout ( 36 ) . All knees were followed up for at least one year and 58 for five years . The mean follow-up time was 4.5 years in the debridement group and 4.3 years in the washout group . At one year 32 of the debridement group and five of the washout group were painfree and at five years 19 of a total of 32 survivors in the debridement group and three of the 26 in the washout group were also free from pain . The mean improvement in a modified Lysholm score was 28 for the debridement group at one year and 21 at five years . In the washout group it was only 5 at one year and 4 at five years . For knees with lesions of the medial femoral condyle of grade s 3 or 4 , arthroscopic debridement appears to be the treatment of choice with over half the patients free from pain after five years Autologous chondrocyte implantation ( ACI ) and mosaicplasty are methods of treating symptomatic articular cartilage defects in the knee . This study represents the first long-term r and omised comparison of the two techniques in 100 patients at a minimum follow-up of ten years . The mean age of the patients at the time of surgery was 31.3 years ( 16 to 49 ) ; the mean duration of symptoms pre-operatively was 7.2 years ( 9 months to 20 years ) . The lesions were large with the mean size for the ACI group being 440.9 mm(2 ) ( 100 to 1050 ) and the mosaicplasty group being 399.6 mm(2 ) ( 100 to 2000 ) . Patients had a mean of 1.5 previous operations ( 0 to 4 ) to the articular cartilage defect . Patients were assessed using the modified Cincinnati knee score and the Stanmore-Bentley Functional Rating system . The number of patients whose repair had failed at ten years was ten of 58 ( 17 % ) in the ACI group and 23 of 42 ( 55 % ) in the mosaicplasty group ( p < 0.001 ) . The functional outcome of those patients with a surviving graft was significantly better in patients who underwent ACI compared with mosaicplasty ( p = 0.02 ) Background Many surgical techniques , including microfracture , periosteal and perichondral grafts , chondrocyte transplantation , and osteochondral grafts , have been studied in an attempt to restore damaged articular cartilage . However , there is no consensus regarding the best method to repair isolated articular cartilage defects of the knee . Questions / purpose sWe compared postoperative functional outcomes , followup MRI appearance , and arthroscopic examination after microfracture ( MF ) , osteochondral autograft transplantation ( OAT ) , or autologous chondrocyte implantation ( ACI ) . Methods We prospect ively investigated 30 knees with MF , 22 with OAT , and 18 with ACI .  Minimum followup was 3 years ( mean , 5 years ; range , 3–10 years ) . We included only patients with isolated cartilage defects and without other knee injuries . The three procedures were compared in terms of function using the Lysholm knee evaluation scale , Tegner activity scale , and Hospital for Special Surgery ( HSS ) score ; modified Outerbridge cartilage grade s using MRI ; and International Cartilage Repair Society ( ICRS ) repair grade using arthroscopy . Results All three procedures showed improvement in functional scores . There were no differences in functional scores and postoperative MRI grade s among the groups . Arthroscopy at 1 year showed excellent or good results in 80 % after MF , 82 % after OAT , and 80 % after ACI . Our study did not show a clear benefit of either ACI or OAT over MF . Conclusions Owing to a lack of superiority of any one treatment , we believe MF is a reasonable option as a first-line therapy given its ease and affordability relative to ACI or OAT.Level of Evidence Level II , therapeutic study . See Guidelines for Authors for a complete description of levels of evidence AIM Matrix-guided autologous chondrocyte implantation ( MACI ) was compared with microfracture ( MFX ) to demonstrate the reconstitution of cartilage over a two-year period using the morphological capabilities of MRI . PATIENTS AND METHODS 27 patients ( 9 females and 18 males , mean age 33 years ) underwent MACI on the knee joint . The defects originated from trauma ( 15 cases ) , osteochondritis dissecans ( 8 cases ) and chronic repetitive trauma ( 4 cases ) and were localized at the condyles ( 24 cases ) or patella ( 3 cases ) . All patients were examined postoperatively after 1 , 3 , 6 , 12 and 24 months with a 1,5 T unit ( Gyroscan , Philips ) using proton- and T2w spinecho and T1w fatsuppressed 3D gradientecho sequences . We measured the signal intensities of the implant and neighbouring cartilage to calculate the contrast-to-noise ratio ( CNR ) , and the thickness of cartilage and implant layers to define the defect filling rate . Finally , partial and complete remission was defined on MRI and compared with clinical data and morphology on MRI . Additionally , 7 patients were treated with MFX and , subsequently examined on MRI with the same protocol . RESULTS After MACI , MRI showed a partial but no complete equilibration of signal intensities of implant and adjacent cartilage over the 1 and 2 year follow-up periods which was shown by reduction of CNR from 21 to 10 on 3D-GE and from 26 to 9 on T2w SE sequences . Continuous growth of the implants result ed in an increased filling of the defects starting at 40 % after 0.5 year to 85 % after 1 or 2 years . Complete remission was found on MRI in 17/27 cases , and remission rate was influenced by etiology of cartilage defect but not by age and gender of patients or size and location of defects . The Lysholm-Gillquist score improved from 49.7 to 97.3 . After MFX  equilibration of signal intensities and growth of the regenerating fibrous cartilage was less pronounced and complete remission was found in only 2/7 cases . In addition , the clinical score improved from 45.5 to 74.2 . CONCLUSION Direct imaging of cartilage with MRI and assessment of clinical scores allowed improved documentation of the outcome after MACI and MFX . MRI showed that MACI is superior to MFX concerning rate of complete remissions and filling of the defect with regenerating tissue . Clinical examinations showed better scores for MACI than for MFX Background Autologous chondrocyte implantation ( ACI ) has demonstrated good and excellent results in over 75 % of patients up to 10 years after surgery . Reports of longer-term outcomes , however , remain limited . Questions / purpose sThe purpose s of this study were to describe the ( 1 ) survivorship of ACI grafts ; ( 2 ) the long-term functional outcomes using vali date d scoring tools after ACI ; and ( 3 ) to provide an analysis of potential predictors for failure . Methods Two hundred ten patients treated with ACI were followed for more than 10 years . Indications for the procedure included symptomatic cartilage defects in all compartments of the knee unresponsive to nonoperative measures . Mean age at surgery was 36 ± 9 years ; mean defect size measured 8.4 ± 5.5 cm2 . Outcome scores were prospect ively collected pre- and postoperatively at the last followup . Results At a mean of 12 ± 2 years followup , 53 of 210 patients ( 25 % ) had at least one failed ACI graft . Nineteen of these patients went on to arthroplasty , 27 patients were salvaged with revision cartilage repair , and seven patients declined further treatment ; three patients were lost to followup . The modified Cincinnati increased from 3.9 ± 1.5 to 6.4 ± 1.5 , WOMAC improved from 39 ± 21 to 23 ± 16 , Knee Society Score ( KSS ) knee score rose from 54 ± 18 to 79 ± 19 , and KSS function from 65 ± 23 to 78 ± 17 ( all p < 0.0001 ) . The Physical Component of the SF-36 score increased from 33 ± 14 to 49 ± 18 , whereas the Mental Component improved from 46 ± 14 to 52 ± 15 ( both p < 0.001 ) . Survivorship was higher in patients with complex versus salvage-type lesions ( p = 0.03 ) with primary ACI versus ACI after prior marrow stimulation ( p = 0.004 ) and with concomitant high tibial osteotomy ( HTO ) versus no HTO ( p = 0.01 ) . Conclusions ACI provided durable outcomes with a survivorship of 71 % at 10 years and improved function in 75 % of patients with symptomatic cartilage defects of the knee at a minimum of 10 years after surgery . A history of prior marrow stimulation as well as the treatment of very large defects was associated with an increased risk of failure . Level of Evidence Level IV , therapeutic study . See Guidelines for Authors for a complete description of levels of evidence BACKGROUND New methods have been used , with promising results , to treat full-thickness cartilage defects . The objective of the present study was to compare autologous chondrocyte implantation with microfracture in a r and omized trial . We are not aware of any previous r and omized studies comparing these methods . METHODS Eighty patients without general osteoarthritis who had a single symptomatic cartilage defect on the femoral condyle in a stable knee were treated with autologous chondrocyte implantation or microfracture  ( forty in each group ) . We used the International Cartilage Repair Society , Lysholm , Short Form-36 ( SF-36 ) , and Tegner forms to collect data . An independent observer performed a follow-up examination at twelve and twenty-four months . Two years postoperatively , arthroscopy with biopsy for  histological evaluation was carried out . The histological evaluation was done by a pathologist and a clinical scientist , both of whom were blinded to each patient 's treatment . RESULTS In general , there were small differences between the two treatment groups . At two years , both groups had significant clinical improvement . According to the SF-36 physical component score at two years postoperatively , the improvement in the microfracture group was significantly better than that in the autologous chondrocyte implantation group ( p = 0.004 ) . Younger and more active patients did better in both groups . There were two failures in the autologous chondrocyte implantation group and one in the microfracture group . No serious complications were reported . Biopsy specimens were obtained from 84 % of the patients , and histological evaluation of repair tissues showed no significant differences between the two groups . We did not find any association between the histological quality of the tissue and the clinical outcome according to the scores on the Lysholm or SF-36 form or the visual analog scale . CONCLUSIONS Both methods had acceptable short-term clinical results . There was no significant difference in macroscopic or histological results between the two treatment groups and no association between the histological findings and the clinical outcome at the two-year time-point . LEVEL OF EVIDENCE Therapeutic study , Level I-1a ( r and omized controlled trial [ significant difference ] ) . See Instructions to Authors for a complete description of levels of evidence Background : The availability remains limited of midterm clinical and radiologic results into matrix-induced autologous chondrocyte implantation ( MACI ) . Outcomes are required to vali date the efficacy of MACI as a suitable surgical treatment option for articular cartilage defects in the knee . Hypothesis : A significant improvement in clinical and magnetic resonance imaging – based ( MRI-based ) outcomes after MACI will exist throughout the postoperative timeline to 5 years after surgery . Furthermore , patient demographics , cartilage defect parameters , and injury/surgery history will be associated with patient and graft outcome , whereas a significant correlation will exist between clinical and MRI-based outcomes at 5 years after surgery . Study Design : Case series ; Level of evidence , 4 . Methods : A prospect i ve evaluation was undertaken to assess clinical and MRI-based outcomes to 5 years in 41 patients ( 53 grafts ) after MACI to the knee . After MACI surgery and a 12-week structured rehabilitation program , patients underwent clinical assessment s ( Knee injury and Osteoarthritis Outcome Score , SF-36 , 6-minute walk test , knee range of motion ) and  MRI assessment s at 3 , 12 , and 24 months , as well as 5 years after surgery . The MRI evaluation assessed 8 previously defined pertinent parameters of graft repair , as well as a combined MRI composite score . Results : A significant improvement ( P < .05 ) was demonstrated for all Knee injury and Osteoarthritis Outcome Score and SF-36 subscales over the postoperative timeline , as well as the 6-minute walk test and active knee extension . A significant improvement ( P < .0001 ) was observed for the MRI composite score , as well as several individual graft scoring parameters . At 5 years after surgery , 67 % of MACI grafts demonstrated complete infill , whereas 89 % demonstrated good to excellent filling of the chondral defect . Patient demographics , cartilage defect parameters , and injury/surgery history demonstrated no significant pertinent correlations with clinical or MRI-based outcomes at 5 years , and no significant correlations existed between clinical and MRI-based outcome measures . At 5 years after surgery , 98 % of patients were satisfied with the ability of MACI surgery to relieve knee pain ; 86 % , with improvement in their ability to perform normal daily tasks ; and 73 % , with their ability to participate in sport 5 years after MACI . Conclusion : These results suggest that MACI provides a suitable midterm treatment option for articular cartilage defects in the knee . Long-term follow-up is essential to confirm whether the repair tissue has the durability required to maintain long-term patient quality of life Background As the natural healing capacity of damaged articular cartilage is poor , joint surface injuries are a prime target for regenerative medicine . Characterized chondrocyte implantation uses an autologous cartilage cell therapy product that has been optimized for its biological potency to form stable cartilage tissue in vivo . Purpose To determine whether , in symptomatic cartilage defects of the femoral condyle , structural regeneration with characterized chondrocyte implantation is superior to repair with microfracture . Study Design R and omized controlled trial ; Level of evidence , 1 . Methods Characterized chondrocyte implantation was compared with microfracture in patients with single grade III to IV symptomatic cartilage defects of the femoral condyles in a multicenter trial . Patients aged 18 to 50 years were r and omized to characterized chondrocyte implantation  ( n = 57 ) or  microfracture  ( n = 61 ) . Structural repair was blindly assessed in biopsy specimens taken at 1 year using ( 1 ) computerized histomorphometry and ( 2 ) evaluation of overall histological components of structural repair . Clinical outcome was measured using the self administered Knee injury and Osteoarthritis Outcome Score . Adverse events were recorded throughout the study . Results Characterized chondrocyte implantation result ed in better structural repair , as assessed by histomorphometry ( P = .003 ) and overall histologic evaluation ( P = .012 ) . Aspects of structural repair relating to chondrocyte phenotype and tissue structure were superior with characterized chondrocyte implantation . Clinical outcome as measured by the Knee injury and Osteoarthritis Outcome Score at 12 to 18 months after characterized chondrocyte implantation was comparable with microfracture at this stage . Both treatment groups had a similar mean baseline overall Knee injury and Osteoarthritis Outcome Score ( 56.30 ± 13.61 and 59.53 ± 14.95 for microfracture and characterized chondrocyte implantation , respectively ) , which increased in both groups to 70.56 ± 12.39 and 72.63 ± 15.55 at 6 months , 73.26 ± 14.66 and 73.10 ± 16.01 at 12 months , and 74.73 ± 17.01 and 75.04 ± 14.50 at 18 months , respectively . Both techniques were generally well tolerated ; the incidence of adverse events after characterized chondrocyte implantation was not markedly increased compared with that for microfracture . Conclusion One year after treatment , characterized chondrocyte implantation was associated with a tissue regenerate that was superior to that after microfracture . Short-term clinical outcome was similar for both treatments . The superior structural outcome may result in improved long-term clinical benefit with characterized chondrocyte implantation . Long-term follow-up is needed to confirm these findings Background : Cartilage defects in the patella are common , and a subset of patients does not respond to nonoperative measures . While most cartilage repair techniques have demonstrated good outcomes in the femoral condyles , the patellofemoral compartment poses special challenges . Hypothesis : Repair of patellar cartilage defects with autologous chondrocyte implantation ( ACI ) will provide lasting improvements in pain and function . Study Design : Case series ; Level of evidence , 4 . Methods : Patients were treated at 1 of 4 participating cartilage repair centers with ACI for cartilage defects in the patella ; bipolar ( patella + trochlea ) defects were included as well . All patients were followed prospect ively for at least 4 years with multiple patient-reported outcome instruments , including the International Knee Documentation Committee , Short Form–12 , modified Cincinnati Rating Scale , Western Ontario and McMaster Universities Osteoarthritis Index , and Knee Society scores . Treatment failure was defined as structural failure of the graft combined with pain requiring revision surgery . Results : A total of 110 patients were available for analysis . As a group , they experienced both statistically significant and clinical ly important improvements in pain and function in all physical outcome scales . The International Knee Documentation Committee improved from 40 ± 14 preoperatively to 69 ± 20 at the last follow-up ; the Cincinnati Rating Scale , from 3.2 ± 1.2 to 6.2 ± 1.8 ; and the Western Ontario and McMaster Universities Osteoarthritis Index , from 50 ± 22 to 29 ± 22 ( all P < .0001 ) . Ninety-two percent of patients stated that they would choose to undergo ACI again , and 86 % rated their knees as good or excellent at the time of final follow-up . Nine patients ( 8 % ) were considered treatment failures , and 16 % reported that their knees were not improved . Conclusion : Cartilage repair in the patellofemoral joint is arguably not without its challenges . Autologous chondrocyte implantation remains off-label in the patella , a fact that needs to be discussed with prospect i ve patients during the informed consent process . However , when performed with attention to patellofemoral biomechanics , self-rated subjective good and excellent outcomes can be achieved in more than 80 % of patients treated with ACI , even in a patient population with large and frequently bipolar defects such as the one presented in this study . However , final functional scores , although significantly improved , still reflected residual disability in this challenging group of patients
BACKGROUND The surfaces of the bones in the knee are covered with articular cartilage , a rubber-like substance that is very smooth , allowing frictionless movement in the joint and acting as a shock absorber .
The cells that form the cartilage are called chondrocytes .
Natural cartilage is called hyaline cartilage .
Articular cartilage has very little capacity for self-repair , so damage may be permanent .
Various methods have been used to try to repair cartilage .
Autologous chondrocyte implantation ( ACI ) involves laboratory culture of cartilage-producing cells from the knee and then implanting them into the chondral defect .
OBJECTIVE To assess the clinical effectiveness and cost-effectiveness of ACI in chondral defects in the knee , compared with microfracture ( MF ) .