The Effects of Intra-Articular Platelet-Rich Plasma Injection According to the Severity of Collagenase-Induced Knee Osteoarthritis in a Rabbit Model Comparison Between Hyaluronic Acid and Platelet-Rich Plasma, Intra-articular Infiltration in the Treatment of Gonarthrosis PRP For the Treatment of Cartilage Pathology Platelet-rich plasma intra-articular injection versus hyaluronic acid viscosupplementation as treatments for cartilage pathology: from early degeneration to osteoarthritis. Platelet-rich plasma vs hyaluronic acid to treat knee degenerative pathology: study design and preliminary results of a randomized controlled trial Platelet-Rich Plasma or Hyaluronate in the Management of Osteochondral Lesions of the Talus Arthroscopic second generation autologous chondrocyte implantation Platelet-rich plasma intra-articular injections for cartilage degeneration and osteoarthritis: single- versus double-spinning approach Platelet-rich plasma: intra-articular knee injections produced favorable results on degenerative cartilage lesions Ultrasound-guided platelet-rich plasma injections for the treatment of osteoarthritis of the hip. Treatment of Knee Joint Osteoarthritis with Autologous Platelet-Rich Plasma in Comparison with Hyaluronic Acid Treatment of knee chondropathy with platelet rich plasma. Preliminary results at 6 months of follow-up with only one injection. Platelet-rich plasma (PRP) injections as an effective treatment for early osteoarthritis Second-generation arthroscopic autologous chondrocyte implantation for the treatment of degenerative cartilage lesions Analyzing the Effects of Platelet Gel on Knee Osteoarthritis in the Rat Model A randomized clinical trial evaluating plasma rich in growth factors (PRGF-Endoret) versus hyaluronic acid in the short-term treatment of symptomatic knee osteoarthritis. Injection of Platelet-Rich Plasma in Patients with Primary and Secondary Knee Osteoarthritis: A Pilot Study Matrix-Assisted Autologous Chondrocyte Transplantation for Cartilage Regeneration in Osteoarthritic Knees Treatment With Platelet-Rich Plasma Is More Effective Than Placebo for Knee Osteoarthritis
Objective To investigate whether the cartilage regenerative effects of intra-aricular platelet-rich plasma ( PRP ) are different , according to the severity of osteoarthritis ( OA ) , in a collagenase-induced knee OA rabbit model . Method New Zeal and white rabbits ( N=21 ) were r and omly divided into three groups . Three different doses ( 0.25 mg , group 1 ; 0.5 mg , group 2 ; and 1.0 mg , group 3 ) of collagenase were injected twice into both knees of each group under an ultrasound guidance . The mean platelet concentration of the PRP fraction was 2,664±970 × 103/µl and was enriched 8.2-times , compared with the whole blood . PRP ( 0.3 ml ) was injected into the left knee and saline ( 0.3 ml ) into the right knee at 4 weeks , and macroscopic and histological scores of both injected knees were evaluated at 9 weeks after the first collagenase injection . Results Macroscopic and histological scores of group 3 were significantly higher than those of group 1 and 2 ( p<0.05 ) . Macroscopic and histological scores of the PRP-injected knees were significantly lower than those of the saline-injected knees , in all groups ( p<0.05 ) . Differences of gross morphologic and histologic scores between saline- and PRP-injected knees in group 3 were significantly higher than those in group 1 and 2 ( p<0.05 ) . Conclusion Intra-articular PRP injection  influences cartilage regeneration in all severities of rabbit knee OA , and the cartilage regenerative power  of PRP injection in moderate knee OA was greater than that in mild or very mild OA . A large pre clinical trial is needed to establish the validity of our study Background : Arthrosis is particularly prevalent in the knee . Infiltration treatment for gonarthrosis is among the most widely used techniques in orthopaedic practice . Purpose : To compare the clinical response of hyaluronic acid ( HA ) and platelet-rich plasma ( PRP ) treatment in 2 groups of patients affected by gonarthrosis . Study Design : R and omized controlled trial ; Level of evidence , 1 . Methods : A total of 120 patients affected by clinical ly and radiographically documented gonarthrosis were included in this study . The gonarthrosis was grade d using the Kellgren-Lawrence radiographic classification scale . The 120 patients were r and omized into 2 study groups in a 1:1 ratio : 60 patients received 4 intra-articular injections of PRP ( specifically , autologous conditioned plasma [ ACP ] , 5.5 mL ) , and 60 patients received 4 intra-articular injections of HA ( 20 mg/2 mL ) . An unblinded physician performed infiltration once a week for 4 weeks into the knee affected by clinical ly relevant gonarthrosis ( in both groups ) . All patients were evaluated with the Western Ontario and McMaster ( WOMAC ) score before the infiltration and at 4 , 12 , and 24 weeks after the first injection . Results : Treatment with a local injection of ACP had a significant effect shortly after the final infiltration and a continuously improving sustained effect up to 24 weeks ( WOMAC score , 65.1 and 36.5 in the HA and ACP groups , respectively ; P < .001 ) , where the clinical outcomes were better compared with the results with HA . In the HA group , the worst results were obtained for grade III gonarthrosis , whereas the clinical results obtained in the ACP group did not show any statistically significant difference in terms of the grade of gonarthrosis . The mean WOMAC scores for grade III gonarthrosis were 74.85 in the HA group and 41.20 in the ACP group ( P < .001 ) . Conclusion : Treatment with ACP showed a significantly better clinical outcome than did treatment with HA , with sustained lower WOMAC scores . Treatment with HA did not seem to be effective in the patients with grade III gonarthrosis In recent years biological strategies are being more widely used to treat cartilage lesions . One of the most exploited novel treatments is Platelet-rich Plasma ( PRP ) , whose high content of growth factors is supposed to determine a regenerative stimulus to cartilaginous tissue . Despite many promising in vitro and in vivo studies , when discussing clinical application a clear indication for the use of PRP can not be assessed . There are initial encouraging clinical data , but only a few r and omized controlled trials have been published , so it is not possible to fully endorse this kind of approach for the treatment of cartilage pathology . Furthermore , study comparison is very difficult due to the great variability in PRP preparation methods , cell content and concentration , storage modalities , activation methods and even application protocol s. These factors partially explain the lack of high quality controlled trials up to now . This paper discusses the main aspects concerning the basic biology of PRP , the principal sources of variability , and summarizes the available literature on PRP use , both in surgical and conservative treatments . Based on current evidence , PRP treatment should only be indicated for low- grade cartilage degeneration and in case of failure of more traditional conservative approaches PURPOSE The aim of our study is to compare the efficacy of platelet-rich plasma ( PRP ) and viscosupplementation ( hyaluronic acid [ HA ] ) intra-articular injections for the treatment of knee cartilage degenerative lesions and osteoarthritis ( OA ) . METHODS The study involved 150 patients affected by cartilage degenerative lesions and early and severe OA . Fifty symptomatic patients were treated with 3 autologous PRP intra-articular injections and were evaluated prospect ively at enrollment and at 2- and 6-month follow-up . The results obtained were compared with 2 homogeneous groups of patients treated with HA injections . One group was treated with injections of high-molecular weight HA ; the other group was treated with low-molecular weight ( LW ) HA .  International Knee Documentation Committee and EQ VAS scores were used for clinical evaluation ; adverse events and patient satisfaction were also recorded . RESULTS At 2 months ' follow-up , the PRP and LW HA groups showed a similar improvement , with higher results compared with the high-molecular weight HA group ( P < .005 ) . At 6 months ' follow-up , better results were observed in the PRP group ( P < .005 ) . PRP and LW HA treatments offered similar results in patients aged over 50 years and in the treatment of advanced OA . PRP showed a better performance compared with HA in younger patients affected by cartilage lesions or early OA . CONCLUSIONS Autologous PRP injections showed more and longer efficacy than HA injections in reducing pain and symptoms and recovering articular function . Better results were achieved in younger and more active patients with a low degree of cartilage degeneration , whereas a worse outcome was obtained in more degenerated joints and in older patients , in whom results similar to those of viscosupplementation have been observed . LEVEL OF EVIDENCE Level II , prospect i ve comparative study Background Platelet Rich Plasma ( PRP ) , a blood-derived product rich in growth factors , is a promising treatment for cartilage defects but there is still a lack of clinical evidence . The aim of this study is to show , through a r and omized double blind prospect i ve trial , the efficacy of this procedure , by comparing PRP to Hyaluronic Acid ( HA ) injections for the treatment of knee chondropathy or osteoarthritis ( OA ) . Methods 109 patients ( 55 treated with HA and 54 with PRP )  were treated and evaluated at 12 months of follow-up . The patients were enrolled according to the following inclusion criteria : age > 18 years , history of chronic ( at least 4 months ) pain or swelling of the knee and imaging findings of degenerative changes of the joint ( Kellgren-Lawrence Score up to 3 ) . A cycle of 3 weekly injections was administered blindly . All patients were prospect ively evaluated before and at 2 , 6 , and 12 months after the treatment by : IKDC , EQ-VAS , TEGNER , and KOOS scores . Range of motion and knee circumference changes were measured over time . Adverse events and patient satisfaction were also recorded . Results Only minor adverse events were detected in some patients , such as mild pain and effusion after the injections , in particular in the PRP group , where a significantly higher post-injective pain reaction was observed ( p=0.039 ) . At the follow-up evaluations , both groups presented a clinical improvement but the comparison between the two groups showed a not statistically significant difference in all scores evaluated . A trend favorable for the PRP group was only found in patients with low grade articular degeneration ( Kellgren-Lawrence score up to 2 ) . Conclusions Results suggest that PRP injections offer a significant clinical improvement up to one year of follow-up . However , conversely to what was shown by the current literature , for middle-aged patients with moderate signs of OA , PRP results were not better than those obtained with HA injections , and thus it should not be considered as first line treatment . More promising results are shown for its use in low grade degeneration , but they still have to be confirmed Background : Nonoperative options for osteochondral lesions ( OCLs ) of the talar dome are limited , and currently , there is a lack of scientific evidence to guide management . Purpose : To evaluate the short-term efficacy and safety of platelet-rich plasma ( PRP ) compared with hyaluronic acid ( HA ) in reducing pain and disability caused by OCLs of the ankle . Study Design : R and omized controlled trial ; Level of evidence , 2 . Methods : Thirty-two patients aged 18 to 60 years were allocated to a treatment by intra-articular injections of either HA ( group 1 ) or PRP ( plasma rich in growth factors [ PRGF ] technique , group 2 ) for OCLs of the talus . Thirty OCLs , 15 per arm , received 3 consecutive intra-articular therapeutic injections and were followed for 28 weeks . The efficacy of the injections in reducing pain and improving function was assessed at each visit using the American Orthopaedic Foot and Ankle Society ( AOFAS ) Ankle-Hindfoot Scale ( AHFS ) ; a visual analog scale ( VAS ) for pain , stiffness , and function ; and the subjective global function score . Results : The majority of patients were men ( n = 23 ; 79 % ) . The AHFS score improved from 66 and 68 to 78 and 92 in groups 1 and 2 , respectively , from baseline to week 28 ( P < .0001 ) , favoring PRP ( P < .05 ) . Mean VAS scores ( 1 = asymptomatic , 10 = severe symptoms ) decreased for pain ( group 1 : 5.6 to 3.1 ; group 2 : 4.1 to 0.9 ) , stiffness ( group 1 : 5.1 to 2.9 ; group 2 : 5.0 to 0.8 ) , and function ( group 1 : 5.8 to 3.5 ; group 2 : 4.7 to 0.8 ) from baseline to week 28 ( P < .0001 ) , favoring PRP ( P < .05 for stiffness , P < .01 for function , P > .05 for pain ) . Subjective global function scores , reported on a scale from 0 to 100 ( with 100 representing healthy , preinjury function ) improved from 56 and 58 at baseline to 73 and 91 by week 28 for groups 1 and 2 , respectively ( P < .01 in favor of PRP ) . Conclusion : Osteochondral lesions of the ankle treated with intra-articular injections of PRP and HA result ed in a decrease in pain scores and an increase in function for at least 6 months , with minimal adverse events .  Platelet-rich plasma treatment led to a significantly better outcome than HA 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 Purpose To compare the safety and efficacy of two different approaches of platelet-rich plasma ( PRP ) production methods as intra-articular injection treatment for knee cartilage degenerative lesions and osteoarthritis ( OA ) . Methods The study involved 144 symptomatic patients affected by cartilage degenerative lesions and OA . Seventy-two patients were treated with 3  injections of platelet concentrate prepared with a single-spinning procedure ( PRGF ) , the other 72 with 3 injections of PRP obtained with a double-spinning approach . The patients were evaluated prospect ively at the enrollment and at 2 , 6 , and 12 months ’ follow-up with IKDC , EQ-VAS and Tegner scores ; adverse events and patient satisfaction were also recorded . Results Both treatment groups presented a statistically significant improvement in all the scores evaluated at all the follow-up times . Better results were achieved in both groups in younger patients with a lower degree of cartilage degeneration . The comparative analysis showed similar improvements with the two procedures : in particular , IKDC subjective evaluation increased from 45.0 ± 10.1 to 59.0 ± 16.2 , 61.3 ± 16.3 , and 61.6 ± 16.2 at 2 , 6 , and 12 months in the PRGF group , and from 42.1 ± 13.5 to 60.8 ± 16.6 , 62.5 ± 19.9 , and 59.9 ± 20.0 at 2 , 6 , and 12 months in the PRP group , respectively . Concerning adverse events , more swelling ( P = 0.03 ) and pain reaction ( P = 0.0005 ) , were found after PRP injections . Conclusions Although PRP injections produced more pain and swelling reaction with respect to that produced by PRGF , similar results were found at the follow-up times , with a significant clinical improvement with respect to the basal level . Better results were achieved in younger patients with a low degree of cartilage degeneration . Level of evidence II Platelet-rich plasma ( PRP ) is a natural concentrate of autologous blood growth factors experimented in different fields of medicine in order to test its potential to enhance tissue regeneration . The aim of our study is to explore this novel approach to treat degenerative lesions of articular cartilage of the knee . One hundred consecutive patients , affected by chronic degenerative condition of the knee , were treated with PRP intra-articular injections ( 115 knees treated ) . The procedure consisted of 150-ml of venous blood collected and twice centrifugated : 3 PRP units of 5 ml each were used for the injections . Patients were clinical ly prospect ively evaluated before and at the end of the treatment , and at 6 and 12 months follow-up . IKDC , objective and subjective , and EQ VAS were used for clinical evaluation . Statistical analysis was performed to evaluate the significance of sex , age , grade of OA and BMI . A statistically significant improvement of all clinical scores was obtained from the basal evaluation to the end of the therapy and at 6–12 months follow-up ( P < 0.0005 ) . The results remained stable from the end of the therapy to 6 months follow up , whereas they became significantly worse at 12 months follow up ( P = 0.02 ) , even if still significantly higher respect to the basal level ( P < 0.0005 ) . The preliminary results indicate that the treatment with PRP injections is safe and has the potential to reduce pain and improve knee function and quality of live in younger patients with low degree of articular degeneration OBJECTIVE To assess the safety and symptomatic changes of IA injections of platelet-rich plasma ( PRP ) in patients with OA of the hip . METHODS Forty patients affected by monolateral severe hip OA were included in the study . Each joint received three IA injections of PRP , which were administered once a week . The primary end point was meaningful pain relief , which was described as a reduction in pain intensity of at least 30 % from baseline levels as evaluated by the WOMAC subscale at 6-months post-treatment . The visual analogue scale ( VAS ) and Harris hip score subscale for pain were used to verify the results . Secondary end points included changes in the level of disability of at least 30 % and the percentage of positive responders , i.e. the number of patients that achieved a > 30 % reduction in pain and disability . RESULTS Statistically significant reductions in VAS , WOMAC and Harris hip subscores for pain and function were reported at 7 weeks and 6 months ( P < 0.05 ) . Twenty-three ( 57.5 % ) patients reported a clinical ly relevant reduction of pain ( 45 % , range 30 - 71 % ) as assessed by the WOMAC subscale . Sixteen ( 40 % ) of these patients were classified as excellent responders who showed an early pain reduction at 6 - 7 weeks , which was sustained at 6 months , and a parallel reduction of disability . Side effects were negligible and were limited to a sensation of heaviness in the injection site . CONCLUSIONS This preliminary non-controlled prospect i ve study supported the safety , tolerability and efficacy of PRP injections for pain relief and improved function in a limited number of patients with OA of the hip Objective This study aim ed to find a simple , cost-effective , and time-efficient method for the preparation of platelet-rich plasma ( PRP ) , so the acquired benefits will be readily available for multiple procedures in smaller outpatient clinics and to explore the safety and efficacy of the application of PRP in the treatment of degenerative lesions of articular cartilage of the knee . Design The study was design ed as a prospect i ve , cohort study with a control group . A total of 120 patients with Grade 1 , 2 , or 3 osteoarthritis according to the Kellgren and Lawrence grading scale were enrolled in the study . One group of patients was treated using three intra-articular applications of PRP , and the second group of patients was given three injections of hyaluronic acid . Outcome measures included the Western Ontario and McMaster Universities Osteoarthritis Index and the 11-point pain intensity Numeric Rating Scale . Results On average , a 4.5-fold increase in platelet concentration was obtained in the PRP group . No severe adverse events were observed . Statistically significantly better results in the Western Ontario and McMaster Universities Osteoarthritis Index and Numeric Rating Scale scores were recorded in a group of patients who received PRP injections after a 3- and 6-mo follow-up . Conclusions Our preliminary findings support the application of autologous PRP as an effective and safe method in the treatment of the initial stages of knee osteoarthritis . Further studies are needed to confirm these results and to investigate the persistence of the beneficial effects observed Application of new biological treatments in orthopaedics is controversial nowadays . Surgeons and practitioners know how difficult can be to choose a solution for chondral injuries . Joint damages are from little contusions , osteochondral fractures , avascular necrosis , osteochondritis and degenerative processes like osteoarthritis and rheumatisms . All mentioned have a common problem : the lack of regenerating hyaline cartilage by themselves . Recently , PRP have been used to treat early moderate chondropathies . Here we show the preliminary results of 30 patients affected by chondropathy of the knee after 6 months treated with a single intrarticular injection of PRP . Thirty patients , 18 - 65 years old , with a diagnosis of I to III Outerbridge chondropathy in the knee , pain for more than 3 months following conservative treatment and no bone axial defect , were treated with one intraarticular injection of PRP ( GPS mini set , BIOMET ) , after written consent and Ethic and Legal Committee approval . VAS and KOOS scores were evaluated before PRP injection and at 1 , 3 and 6 months after the treatment . ANOVA with repeated measures using the SPSS showed significantly better results in term of KOOS and VAS scores at 1 , 3 and 6 months respect to the pre-injection value ( p less than 0,05 ) We think that PRP treatment is a promising alternative for the treatment of knee chondropathy ; however its efficacy has to be demonstrated with more clinical works , with longer follow up and with greater number of patients , even with controlled and r and omized trials . In our study only one injection of PRP has been able to allow a clinical improvement , suggesting the possibility to avoid multiple injections protocol s , and consequently reducing the health expenses . Until the efficacy of PRP will not be definitely demonstrated , surgeon should be very prudent in indications The aims of this study were to analyze the range of cartilage damage and patellofemoral joint ( PFJ ) degeneration in degenerative osteoarthritis ( OA ) and determine the duration for the positive effects of platelet-rich plasma ( PRP ) injection . This study included 65 patients suffering from OA that were treated with intra-articular PRP injection .  The patients were prospect ively evaluated at 1 , 3 , 6 , 9 , and 12 months after the procedure using a visual analogue scale ( VAS ) score and an International Knee Documentation Committee ( IKDC ) score . Clinical improvement in the average VAS score from 7.4 before the procedure to 4.2 at 6 months post-procedure had been reported , but the symptoms tended to deteriorate to 5.0 1 year after injection . The IKDC score also showed statistical significance ( P < 0.05 ) . Patients reported relapsed pain 8.8 months after the procedure . Developing degeneration according to the Kellgren – Lawrence grade reduced the clinical effects of PRP ( P < 0.05 ) and also accelerated the time for feeling relapsed pain ( P < 0.05 ) . There was a statistically significant negative correlation between patient age and the PRP potential in the VAS score ( slope = 0.1667 ) and IKDC score ( slope = 1.3333 ) . The presence of PFJ degeneration is expected to produce a worse outcome ( P < 0.05 ) . While intra-articular PRP injection can be used for the treatment of early OA , increasing age , and developing degeneration result in a decreased potential for PRP injection therapy Purpose Degenerative cartilage lesions present a negative joint environment , which may have a negative effect on the process of cartilage regeneration . The aim of this study is to analyze the clinical outcome obtained with the treatment for isolated degenerative knee cartilage lesions by second-generation arthroscopic autologous chondrocyte implantation ( ACI ) . Methods Fifty-eight consecutive patients affected by focal degenerative chondral lesions of the femoral condyles and trochlea were treated by second-generation arthroscopic ACI .  The mean age at surgery was 34.7 ± 9.1 years and the average defect size was 2.3 ± 0.9 cm2 . The patients were prospect ively evaluated with IKDC , EQ-VAS , and Tegner scores preoperatively , at 2 and 6 years . Results A statistically significant improvement was observed in all scores from the basal evaluation to the final follow-up . The IKDC subjective score improved from 39.3 ± 13.6 to 68.8 ± 22.7 and 68.5 ± 23.9 at the 2- and 6-year follow-ups , respectively , with a significant improvement ( P < 0.0005 ) and stable results over time ; the same trend was confirmed by the EQ-VAS and Tegner scores . The worst results were found in patients with a low physical activity level , women , and those having undergone previous surgery , whereas the symptom duration before surgery did not influence the final outcome . The failure rate was 18.5 % . Conclusions Despite a significant improvement , the results were lower with respect to the outcome reported in different study population s , and the number of failures was markedly higher , too . Tissue-engineered cartilage implantation is a promising approach for the treatment of degenerative chondral lesions , but graft properties , besides mechanical and biochemical joint environment , have to be improved . Level of evidence Case series , Level IV Platelet gel ( PG ) includes concentrated dose of growth factors which plays role in physiological processes of healing . The goal of this study is to evaluate repairing effects of intra-articular injection of PG use in a rat model of knee osteoarthritis ( OA ) . A total of 20 rats were r and omly distributed into a  PG group and a control group . Both the groups were induced OA in knee joints with intra-articular formaline injection . The rats in the PG group and the control group were injected in the knee joint with PG and 0.9 % NaCl solution , respectively . Two weeks after last injections , all rats were sacrificed by ether asphyxiation . Tissue sample s were obtained from the knee joints and were examined histopathologically . No statistically significant differences were found between the groups regarding cartilage healing ( P > .05 ) . We were unable to determine any beneficial or harmful effects of PG on joint cartilage healing in OA PURPOSE This multicenter , double-blind clinical trial evaluated and compared the efficacy and safety of PRGF-Endoret ( BTI Biotechnology Institute , Vitoria-Gasteiz , Spain ) , an autologous biological therapy for regenerative purpose s , versus hyaluronic acid ( HA ) as a short-term treatment for knee pain from osteoarthritis . METHODS We r and omly assigned 176 patients with symptomatic knee osteoarthritis to receive infiltrations with PRGF-Endoret or with HA ( 3 injections on a weekly basis ) . The primary outcome measure was a 50 % decrease in knee pain from baseline to week 24 . As secondary outcomes , we also assessed pain , stiffness , and physical function using the Western Ontario and McMaster Universities Osteoarthritis Index ; the rate of response using the criteria of the Outcome Measures for Rheumatology Committee and Osteoarthritis Research Society International St and ing Committee for Clinical Trials Response Criteria Initiative ( OMERACT-OARSI ) ; and safety . RESULTS The mean age of the patients was 59.8 years , and 52 % were women . Compared with the rate of response to HA , the rate of response to PRGF-Endoret was 14.1 percentage points higher ( 95 % confidence interval , 0.5 to 27.6 ; P = .044 ) . Regarding the secondary outcome measures , the rate of response to PRGF-Endoret was higher in all cases , although no significant differences were reached . Adverse events were mild and evenly distributed between the groups . CONCLUSIONS Plasma rich in growth factors showed superior short-term results when compared with HA in a r and omized controlled trial , with a comparable safety profile , in alleviating symptoms of mild to moderate osteoarthritis of the knee . LEVEL OF EVIDENCE Level I , r and omized controlled multicenter trial Sampson S , Reed M , Silvers H , Meng M , M and elbaum B : Injection of platelet-rich plasma in patients with primary and secondary knee osteoarthritis : A pilot study . Objective : To evaluate the clinical effects of intraarticular platelet-rich plasma ( PRP ) injections in a small group of patients with primary and secondary osteoarthritis . Most of the current treatments for osteoarthritis are palliative and attack the symptoms rather than influencing the biochemical environment of the joint . Autologous platelet-rich plasma has emerged as a treatment option for tendinopathies and chronic wounds . In addition to release of growth factors , platelet-rich plasma also promotes concentrated anti-inflammatory signals including interleukin-1ra , which has been a focus of emerging treatments for osteoarthritis . Design : In this single-center , uncontrolled , prospect i ve preliminary study , 14 patients with primary and secondary knee osteoarthritis who met the study criteria received three platelet-rich plasma injections in the affected knee at ∼4-wk intervals . Outcome measures included the Brittberg-Peterson Visual Pain ( Visual Analog Scale [ VAS ] ) , Activities , and Expectations score and the Knee Injury and Osteoarthritis Outcome Scores at preinjection visit at 2- , 5- , 11- , 18- , and 52-wk follow-up visits . Musculoskeletal ultrasound was used to measure cartilage thickness . Results : There were no adverse events reported . The study demonstrated significant and almost linear improvements in Knee Injury and Osteoarthritis Outcome Scores , including pain and symptom relief . Brittberg-Peterson VAS showed many improvements including reduced pain after knee movement and at rest . Cartilage assessment was limited because of the small sample size . The majority of the patients expressed a favorable outcome at 12 mos after treatment . Conclusions : The positive trends and safety profile demonstrated could potentially be used to inspire a larger , blinded , and r and omized clinical trial to determine whether platelet-rich plasma is safe and effective for the treatment of knee osteoarthritis Background : Young patients with osteoarthritic knees are a challenging population because of a combination of high functional dem and s and limited indication for joint replacement . Purpose : To analyze the potential of the cartilage regenerative approach by documenting the results and failures of matrix-assisted autologous chondrocyte transplantation ( MACT ) at midterm follow-up . Study Design : Case series ; Level of evidence , 4 . Methods : Forty-four patients affected by cartilage lesions in osteoarthritic knees underwent MACT as a salvage procedure . The mean age at surgery was 42 years ( range , 20 - 58 years ) , and the average defect size was 4 cm2 ( range , 1.5 - 9 cm2 ) . Patients were prospect ively evaluated with the subjective International Knee Documentation Committee ( IKDC ) , EuroQol visual analog scale ( EQ-VAS ) , and Tegner scores preoperatively ; at 1 , 2 , and 5 years ; and at a final assessment at 9 years ’ mean follow-up . Adverse events and failures were also reported . Results : A statistically significant improvement was observed in all scores from the initial evaluation to the final follow-up . The mean ± st and ard deviation IKDC subjective score improved from 38.0 ± 15.8 to 67.0 ± 18.3 at 2 years ( P < .0005 ) , with a subsequent decrease to 57.8 ± 20.6 at the final follow-up ( P = .012 ) . The same trend was confirmed by the EQ-VAS score . The activity level revealed by the Tegner score improved at all follow-ups but without achieving the preinjury level . The analysis of the influencing factors showed the importance of the meniscus condition , revealing a significantly inferior outcome in knees with previous or combined partial meniscectomy procedures . During the study period , 12 patients had failed results , producing a cumulative failure rate of 27.3 % . At the last evaluation , half of the patients considered their condition not better than before the treatment , and 39 % would not repeat the treatment considering the results obtained . Conclusion : Despite a statistically significant improvement , the clinical outcome was poor . A higher improvement could be obtained in patients who had not undergone previous or combined meniscectomies , but this was limited over time . The failure rate was also high , regardless of the degree of osteoarthritis . Tissue-engineered cartilage implantation is question able for this indication , and the limits of this scaffold-based procedure have to be considered if it is used as a salvage procedure for young patients affected by knee osteoarthritis Background : Specific growth factors have been proposed as therapeutic proteins for cartilage repair . Hypothesis : Platelet-rich plasma ( PRP ) provides symptomatic relief in early osteoarthritis ( OA ) of the knee . Study Design : R and omized controlled trial ; Level of evidence , 1 . Methods : A total of 78 patients ( 156 knees ) with bilateral OA were divided r and omly into 3 groups . Group A ( 52 knees ) received a single injection of PRP , group B ( 50 knees ) received 2 injections of PRP 3 weeks apart , and group C ( 46 knees ) received a single injection of normal saline . White blood cell (WBC)–filtered PRP with a platelet count 3 times that of baseline ( PRP type 4B ) was administered in all . All the groups were homogeneous and comparable in baseline characteristics . Clinical outcome was evaluated using the Western Ontario and McMaster Universities Arthritis Index ( WOMAC ) question naire before treatment and at 6 weeks , 3 months , and 6 months after treatment . They were also evaluated for pain by a visual analog scale , and overall satisfaction with the procedure and complications were noted . Results : Statistically significant improvement in all WOMAC parameters was noted in groups A and B within 2 to 3 weeks and lasting until the final follow-up at 6 months , with slight worsening at the 6-month follow-up . The mean WOMAC scores ( pain , stiffness , physical function , and total score ) for group A at baseline were 10.18 , 3.12 , 36.56 , and 49.86 , respectively , and at final follow-up were 5.00 , 2.10 , 20.08 , and 27.18 , respectively , showing significant improvement . Similar improvement was noted in group B ( mean WOMAC scores at baseline : 10.62 , 3.50 , 39.10 , and 53.20 , respectively ; mean WOMAC scores at final follow-up : 6.18 , 1.88 , 22.40 , and 30.48 , respectively ) . In group C , the mean WOMAC scores deteriorated from baseline ( 9.04 , 2.70 , 33.80 , and 45.54 , respectively ) to final follow-up ( 10.87 , 2.76 , 39.46 , and 53.09 , respectively ) . The 3 groups were compared with each other , and no improvement was noted in group C as compared with groups A and B ( P < .001 ) . There was no difference between groups A and B , and there was no influence of age , sex , weight , or body mass index on the outcome . Knees with Ahlback grade 1 fared better than those with grade 2 . Mild complications such as nausea and dizziness , which were of short duration , were observed in 6 patients ( 22.2 % ) in group A and 11 patients ( 44 % ) in group B. Conclusion : A single dose of WBC-filtered PRP in concentrations of 10 times the normal amount is as effective as 2 injections to alleviate symptoms in early knee OA . The results , however , deteriorate after 6 months . Both groups treated with PRP had better results than did the group injected with saline only
Purpose The aim of this review was to analyze the available evidence on the clinical application of this biological approach for the injective treatment of  cartilage lesions and joint degeneration  , together with pre clinical studies to support the rationale for the use of platelet concentrates , to shed some light and give indications on what to treat and what to expect from intra-articular injections of platelet-rich plasma ( PRP ) .