Reproducibility of femoral offset following short stem and straight stem total hip arthroplasty. No Difference in Periprosthetic Bone Loss and Fixation Between a Standard-Length Stem and a Shorter Version in Cementless Total Hip Arthroplasty. A Randomized Controlled Trial. Comparison of Bone Remodeling Between an Anatomic Short Stem and a Straight Stem in 1-Stage Bilateral Total Hip Arthroplasty. [Periprosthetic femoral bone reaction after total hip arthroplasty with preservation of the collum femoris : CT-assisted osteodensitometry 1 and 3 years postoperatively]. Bone remodelling after femoral short stem implantation in total hip arthroplasty: 1-year results from a randomized DEXA study Bone remodelling around the Metha short stem in total hip arthroplasty: a prospective dual-energy X-ray absorptiometry study Lower periprosthetic bone loss and good fixation of an ultra-short stem compared to a conventional stem in uncemented total hip arthroplasty A prospective cohort study on the short collum femoris-preserving (CFP) stem using RSA and DXA Minimally-invasive total hip arthroplasty will improve early postoperative outcomes: a prospective, randomized, controlled trial Prospective study of a cementless total hip arthroplasty with a collum femoris preserving stem and a trabeculae oriented pressfit cup: minimun 6-year follow-up Primary total hip arthroplasty with a proximally porous-coated femoral stem. Highly Crosslinked Polyethylene Does Not Reduce Aseptic Loosening in Cemented THA 10-year Findings of a Randomized Study Hybrid Total Hip Arthroplasty with a Precoated Offset Stem: Four to Nine-Year Results* Minimally invasive total hip replacement via the anterolateral approach in the supine position A minimal-incision technique in total hip arthroplasty does not improve early postoperative outcomes. A prospective, randomized, controlled trial.
Bone stock-preserving short stem prostheses have gained importance in  total hip arthroplasty ( THA ) with the use of minimally invasive surgical procedures . Because of their metaphyseal fixation and their dependency on the calcar radius , it is unknown whether the femoral offset can be reproduced with the same accuracy following short stem vs st and ard stem THA . This study clarifies whether it is possible to restore the femoral offset using a short stem prosthesis ( Fitmore ; Zimmer , Warsaw , Indiana ) compared with a conventional straight stem prosthesis ( CLS ; Zimmer ) following minimally invasive implantation using an anterolateral approach . In a prospect i ve , r and omized , double-blinded study , 80 patients underwent THA using a short stem ( SS group ; n=40 ) or CLS implant ( control group ; n=40 ) . Follow-up examinations were conducted 6 weeks postoperatively . Radiological and functional outcomes were measured . Subjective assessment of quality of life was evaluated using the Harris Hip Score ( HHS ) , the Short Form 36-item health survey ( SF-36 ) , and the Western Ontario and McMaster Universities Osteoarthritis Index ( WOMAC ) . Pre- and postoperative comparison of the groups ' change in offset showed no significant differences ( SS group difference from pre- to postoperative , 6.1±6.5 mm ; control group difference from pre- to postoperative , 6.5±7.1 mm ; P=.93 ) . Group comparison after 6 weeks revealed no significant differences in HHS , SF-36 , or WOMAC . Based on these data , an equivalent reproducibility of the femoral offset was demonstrated following short stem and straight stem THA using a minimally invasive anterolateral approach . If the long-term results of short stems show a comparable survival , they represent a sensible alternative to st and ard stems BACKGROUND Cementless femoral stems in total hip arthroplasty provide dependable clinical and radiographic results in the treatment of osteoarthritis . Stem length might affect the preservation of proximal bone stock and stability . We hypothesized that a shorter stem decreases proximal bone loss without affecting implant stability . METHODS We r and omly assigned 60 patients aged between 50 and 70 years to either a st and ard cementless femoral stem or a 35-mm shorter version . Patients were followed with dual-energy X-ray absorptiometry , radiostereometric analysis , Harris hip score , Western Ontario and McMaster Universities Osteoarthritis Index score , and clinical follow-up at 3 , 6 , 12 , and 24 months . The trial is registered on Clinical Trials.gov/. RESULTS After 24 months , short stems had on average 3.8 % ( 95 % confidence interval , 1.2%-8.9 % ) more bone loss in zone 1 compared to st and ard stems ( P = .14 ) . In zone 7 , the bone loss was on average 6.5 % ( 95 % confidence interval , 6.6%-19.7 % ) higher compared to st and ard stems ( P = .33 ) . After 24 months , st and ard stems had migrated 0.93 mm ( range , 0.25 - 4.66 mm ) and short stems 0.93 mm ( range , 0.17 - 2.96 mm ; Student t-test after log transformation , P = .3 ) . Patient-reported outcome measures were similar in both groups . One patient in the st and ard stem group was diagnosed with infection , one with a posterior dislocation , and one with a deep venous thrombosis . No stems were revised . CONCLUSION There were no statistically significant differences in periprosthetic bone loss or fixation between the stems at 24 months BACKGROUND Femurs of dysplastic hips exhibit specific abnormalities , and use of modular or specially design ed components is recommended . An anatomic short stem was previously design ed specifically for dysplastic hips using 3-dimensional data acquired from dysplastic patients . To investigate effects of stem geometry on bone remodeling , we undertook a prospect i ve , r and omized study of patients who had undergone 1-stage bilateral total hip arthroplasty ( THA ) with the anatomic short stem on one side and a conventional straight stem on the other . METHODS The study included 36 patients who underwent the above THA procedure . We assessed bone mineral density as well as the presence of cancellous condensation or bony atrophy due to stress shielding based on the analysis of Gruen 's zones and newly defined equal-interval zones , at an average follow-up period of 9.2 years . RESULTS All stems were bone ingrown stable . Cancellous condensation was observed more proximally , and areas of bone atrophy were narrower on the anatomic short stem side than on the straight stem side . Bone mineral density values reflected results of cancellous condensation and stress shielding and were higher in more proximal zones on the anatomic short stem side than on the straight stem side . CONCLUSION Although radiographic results indicated good midterm outcomes of THA with both stems , the loading pattern differed . The anatomic short stem achieved its design purpose in terms of proximal fixation and load transfer and led to better preservation of the proximal femur BACKGROUND Short-stemmed cementless femoral components in total hip arthroplasty have been design ed to preserve the proximal femoral bone stock by load transfer to the femoral metaphysis . An in vivo method of computed tomography-assisted ( CT ) osteodensitometry after total hip arthroplasty is presented which differentiates between cortical and cancellous bone density ( BD ) changes around uncemented femoral components . PATIENTS AND METHODS Cortical and cancellous periprosthetic femoral BD ( mg Ca HA/ml ) was determined prospect ively in 31 patients at day 10 , 1 year and 3 years after total hip arthroplasty with preservation of the collum femoris ( C.F.P.-stem , Link , Hamburg , Germany ) using computed tomography-assisted osteodensitometry .  Clinical results ( Harris hip score ) and plain x-rays were assessed in all cases . RESULTS Progressive proximal cortical BD loss was observed between the 1 year ( Ø -8 % ) and 3 year ( Ø -22 % ) postoperative measurements . Distal to the trochanter minor no significant cortical BD changes were observed . Proximal cancellous BD decreased progressively between the 1 year ( Ø -33 % ) and 3 year ( Ø -45 % ) analyses . The Harris hip score improved from 45 points pre-operatively to 93 points at the 3 year follow-up . All x-rays showed signs of stable ingrowth . CONCLUSION Periprosthetic CT osteodensitometry has the technical ability to discriminate between cortical and cancellous bone structures with respect to strain-adapted remodeling . Progressive proximal cortical and cancellous BD loss indicates that metaphyseal fixation can not be achieved with the analyzed C.F.P. stem design . The lack of cortical BD loss below the trochanter minor suggests diaphyseal fixation of the implanted stem Introduction Short stem prostheses have been developed to preserve proximal femoral bone stock . This prospect i ve , r and omized study compared periprosthetic bone remodelling following short and straight stem implantation 1 year after surgery . Material s and methods One hundred and forty-four consecutive patients undergoing total hip arthroplasty were r and omized to either a Fitmore short or a cementless straight stem ( both Zimmer , Winterthur , Switzerl and ) . Periprosthetic bone mineral density ( BMD ) was measured using dual-energy X-ray absorptiometry performed the day before surgery and at 7 days , 3 months and 1 year postoperatively . Furthermore , the HHS and the WOMAC were obtained . Results One hundred and thirty-eight patients completed 1-year follow-up . Periprosthetic BMD changes at 1 year were most pronounced in the proximal medial region of interest ( ROI ) 7 with −17.2 % after short stem and −16.7 % after straight implantation ( p = 0.67 ) . However , there was significantly less BMD reduction in ROI 6 following short ( −4.7 % ) versus straight stem ( −10.8 % ) implantation ( p = 0.01 ) . There were no significant differences between the two groups in terms of the HHS and the WOMAC either before or after surgery . Conclusion One year after surgery , both stems showed an implant-specific periprosthetic bone remodelling . Nevertheless , proximal load transfer was more pronounced after short stem implantation than with a straight stem Purpose On the basis of positive clinical results with mid- and long-term follow-up using the Mayo short stem , the Metha neck-preserving stem ( BBraun , Aesculap , Tuttlingen , Germany ) was introduced . The purpose of this study was to vali date the implant design by direct acquisition of bone remodelling data from total hip arthroplasty ( THA ) recipients using dual-energy X-ray absorptiometry ( DEXA ) . Methods After power analysis , 25 patients were included in this prospect i ve study . Patients were examined clinical ly and underwent DEXA examinations preoperatively and postoperatively at one week , six months and one and two years after THA . Gruen zones were adapted to the short stem design ( R1–R7 ) . Results The Harris Hip Score ( HHS ) increased significantly by 31 points . No stem had to be revised . Bone mineral density ( BMD ) in the greater trochanter decreased significantly from 0.78 g/cm2 postoperatively to 0.72 g/cm2 two years after surgery . Marginal changes were seen in the lateral distal regions ( R4–R5 ) . In the minor trochanter region , BMD increased significantly after two years by 12.9 % . In the calcar region , BMD exceeded the baseline value by 6.1 % two years after implantation . Conclusions Stress shielding seems to occur at the greater trochanter due to the vast cross-section of the implant . However , the aim of proximal load transfer of the Metha stem seems to be partially achieved . DEXA analysis revealed a concentrated load distribution on the medial portion of the femur , which is an important region to guarantee long-term implant survival Background and purpose — We hypothesized that an ultra-short stem would load the proximal femur in a more physiological way and could therefore reduce the adaptive periprosthetic bone loss known as stress shielding . Patients and methods — 51 patients with primary hip osteoarthritis were r and omized to total hip arthroplasty ( THA ) with either an ultra-short stem or a conventional tapered stem . The primary endpoint was change in periprosthetic bone mineral density ( BMD ) , measured with dual-energy x-ray absorptiometry ( DXA ) , in Gruen zones 1 and 7 , two years after surgery . Secondary endpoints were change in periprosthetic BMD in the entire periprosthetic region , i.e. Gruen zones 1 through 7 , stem migration measured with radiostereometric analysis ( RSA ) , and function measured with self-administered functional scores . Results — The periprosthetic decrease in BMD was statistically significantly lower with the ultra-short stem . In Gruen zone 1 , the mean difference was 18 % ( 95 % CI : −27 % to −10 % ) . In zone 7 , the difference was 5 % ( CI : −12 % to −3 % ) and for Gruen zones 1–7 the difference was also 5 % ( CI : −9 % to −2 % ) . During the first 6 weeks postoperatively , the ultra-short stems  migrated 0.77 mm more on average than the conventional stems . 3 months after surgery , no further migration was seen . The functional scores improved during the study and were similar in the 2 groups . Interpretation — Up to 2 years after total hip arthroplasty , compared to the conventional tapered stem the ultra-short uncemented anatomical stem induced lower periprosthetic bone loss and had equally excellent stem fixation and clinical outcome Background and purpose Short femoral stems have been introduced in total hip arthroplasty in order to save proximal bone stock . We hypothesized that a short stem preserves periprosthetic bone mineral density ( BMD ) and provides good primary stability . Methods We carried out a prospect i ve cohort study of 30 patients receiving the collum femoris-preserving ( CFP ) stem .  Preoperative total hip BMD and postoperative periprosthetic BMD in Gruen zones 1–7 were investigated by dual-energy x-ray absorptiometry ( DXA ) , stem migration was analyzed by radiostereometric analysis ( RSA ) , and the Harris hip score ( HHS ) was determined . Results 2 patients were excluded intraoperatively and 1 patient was revised due to a deep infection , leaving 27 patients for analysis . The mean HHS increased from 49 ( 24–79 ) preoperatively to 99 ( 92–100 ) after 2 years . DXA after 1 year showed substantial loss of BMD in Gruen zone 7 ( –31 % ) , zone 6 ( –19 % ) , and zone 2 ( –13 % , p < 0.001 ) compared to baseline BMD determined immediately postoperatively . The bone loss in these regions did not recover after 2 years , whereas the more moderate bone loss in Gruen zones 1 , 3 , and 5 partially recovered . There was a correlation between low preoperative total hip BMD and a higher amount of bone loss in Gruen zones 2 , 6 and 7 . RSA showed minor micromotion of the stem : mean subsidence was 0.13 ( 95 % CI : –0.28 to 0.01 ) mm and mean rotation around the longitudinal axis was 0.01º ( 95 % CI : –0.1 to 0.39 ) after 2 years . Interpretation We conclude that substantial loss in proximal periprosthetic BMD can not be prevented by the use of a novel type of short , curved stem , and forces appear to be transmitted distally . However , the stems showed very small migration — a characteristic of stable uncemented implants Background The rehabilitation of patients for total hip arthroplasty is unsatisfactory , especially the prolonged rehabilitation . Aims To explore indications and key points of anterolateral minimally-invasive total hip arthroplasty . Methods 110 patients admitted for unilateral total hip arthroplasty were r and omly selected for surgery with either anterolateral minimally-invasive incision or st and ard posterolateral incision .  Demographic data , perioperative index and postoperative function index were recorded and statistically analyzed . Results No significant difference was detected in operation time , abduction angle , anteversion angle , stem alignment and stem fixation . The incision length , blood loss , perioperative transfusion and 100-mm VAS score at the first 24 h in minimally-invasive group were significantly lower . The Harris hip score and Barthel index were significantly higher in minimally-invasive group at 3 months ’ follow-up , but not significantly different 3 years after operation . Conclusions There are fewer traumas , fewer blood losses and more rapid recovery in this approach Aim Tissue sparing hip prostheses are becoming more and more popular especially for the treatment of younger patients . The objective of this study was to evaluate the clinical and radiological results after insertion of a tissue sparing hip prosthesis . Method In 47 consecutive non-selected patients ( 50 hips ) , the clinical and radiographic results of cementless total hip arthroplasty using a collum femoris preserving stem , a pressfit cup and an alumina – polyethylene pairing were prospect ively evaluated . The mean age at index-surgery was 58 ( 36–82 ) years , there were 38 women and 9 men . After a mean follow-up of 6.8 years ( minimum 6.1 years ) , two patients had died and one patient underwent revision surgery due to aseptic loosening of the stem . Results The overall survival rate of the acetabular component was 100 % and of the femoral component 98 % . The mean Harris hip score at follow-up was 94 points . Conclusion The mid-term survival with this type of total hip arthroplasty is excellent and compares equal with uncemented straight stems in this age group BACKGROUND The use of cementless , proximally porous-coated femoral stems for total hip arthroplasty has increased in popularity . The purpose of the present report was to examine the five to ten-year results associated with the use of a so-called second-generation circumferentially proximally porous-coated titanium-alloy stem . METHODS Between 1991 and 1994 , 123 Harris-Galante Multilock femoral stems were implanted in 101 patients . The average age of the patients at the time of surgery was 53.8 years . The patients were followed prospect ively and were reevaluated at a minimum of five years postoperatively . No patient was lost to follow-up . Twenty-five patients ( thirty hips ) were interviewed by telephone , and four patients ( five hips ) died during the study period because of problems that were unrelated to the operation . The remaining seventy-two patients ( eighty-eight hips ) had a minimum of five years of clinical and radiographic follow-up . RESULTS The average duration of follow-up was seventy-eight months . At the time of the most recent follow-up , the average Harris Hip Score was 95 points . Eighty-seven ( 99 % ) of eighty-eight stems were biologically stable , with eighty-four hips ( 95 % ) having osseous ingrowth and three hips ( 3 % ) having stable fibrous fixation . One stem was revised because of loosening . Thirty-three hips ( 38 % ) had minimal proximal osteolysis , and no hip had diaphyseal osteolysis . Seventy-two hips ( 82 % ) had some degree of stress-shielding in the proximal metaphysis , but only two hips had cortical resorption . None of these patients required additional surgery , and all reported a satisfactory outcome . CONCLUSIONS Given the young age and high activity level of these patients , this stem fared well : the levels of patient function and satisfaction were high , the rates of loosening and revision were very low , and distal osteolysis did not occur . Osseous fixation occurred reliably . Proximal stress-shielding was seen but did not seem to be clinical ly important Background Polyethylene ( PE ) wear particles are believed to cause aseptic loosening and thereby impair function in hip arthroplasty .  Highly crosslinked polyethylene ( XLPE ) has low short- and medium-term wear rates . However , the long-term wear characteristics are unknown and it is unclear whether reduced wear particle burden improves function and survival of cemented hip arthroplasty . Questions / purpose sWe asked whether XLPE wear rates remain low up to 10 years and whether this leads to improved implant fixation , periprosthetic bone quality , and clinical function compared to conventional PE . Methods We r and omized 60 patients ( 61 hips ) to receive either PE or XLPE cemented cups combined with a cemented stem .  At 10 years postoperatively , 51 patients ( 52 hips ) were evaluated for polyethylene wear and component migration estimation by radiostereometry , for radiolucent lines , bone densitometry , and Harris hip and pain scores . Revisions were recorded . Results XLPE cups had a lower mean three-dimensional wear rate between 2 and 10 years compared to conventional PE hips : 0.005 mm/year versus 0.056 mm/year . We found no differences in cup migration , bone mineral density , radiolucencies , functional scores , and revision rate . There was a trend toward improved stem fixation in the XLPE group . The overall stem failure rate was comparably high , without influencing wear rate in XLPE hips . Conclusions XLPE displayed a low wear rate up to 10 years when used in cemented THA , but we found no clear benefits in any other parameters . Further research is needed to determine whether cemented THA design s with XLPE are less prone to stem loosening . Level of Evidence Level I , therapeutic study . See the Instructions for Authors for a complete description of levels of evidence Background : Use of modern cementing techniques for fixation of femoral components in total hip arthroplasty has had excellent clinical and radiographic results in most patients . However , several authors have described early loosening of femoral components with roughened and precoated finishes . The purpose of this study was to examine the performance of the precoated Iowa stem , which has increased offset , and to compare the results with those of another cemented precoated femoral component with st and ard offset used at our institution . Methods : We carried out a prospect i ve analysis of 102 primary hybrid total hip arthroplasties ( a cementless acetabular component and a cemented femoral component ) performed with use of the Iowa femoral component in ninety-five patients at our institution . The Iowa stem was used in hips that required greater offset than is available with st and ard stems as determined by preoperative templating . The average age of the patients at the time of the index procedure was sixty-nine years . Sixteen patients ( seventeen hips ) died before the forty-eight-month minimum follow-up period had elapsed . Two patients were lost to follow-up , and radiographic follow-up was incomplete for one . The mean duration of clinical and radiographic follow-up of the remaining eighty-two hips in the seventy-six surviving patients was sixty-five months ( range , forty-eight to 104 months ) . Results : The average preoperative Harris hip score of 47 points ( range , 16 to 69 points ) improved to an average of 87 points ( range , 24 to 100 points ) at the time of the review . Two hips underwent femoral component revision . Four femoral stems were radiographically loose at an average of thirty-four months . Femoral osteolysis was seen in five hips ( 6 percent ) at an average of fifty-four months postoperatively . No acetabular component was revised because of aseptic loosening . According to Kaplan-Meier analysis , the seven-year survival rate , with an end point of femoral revision , osteolysis , or stem debonding , was 90.6 percent ( 95 percent confidence interval , 0.87 to 0.94 ) . Conclusions : The prevalence of revision , osteolysis , and loosening after total hip arthroplasty with the  Iowa femoral component  at our institution was higher than that seen in our series of Harris Precoat stems , which had a survival rate of 98.4 percent ( 95 percent confidence interval , 0.97 to 1.00 ) at ten years with the same end points . The design of the Iowa stem may make it difficult to achieve a good cement mantle , and , in combination with the geometry and increased offset of the stem , may compromise the long-term survival of this cemented femoral component Total  hip arthroplasty  through minimally invasive procedures potentially reduces operative trauma , which is expected to result in improved recovery and rehabilitation . We presently perform  total hip arthroplasty  using minimally invasive techniques via an anterolateral modification of the Watson-Jones approach . This approach is performed in the supine position and requires sterile draping of both legs . It also involves a modified operative technique which preserves the pelvitrochanteric muscles and extends the release of the hip capsule . In order to employ a proven implant system ( BICON-PLUS ® threaded cup , SL-PLUS ® stem ) , it was necessary to modify the stem rasps and use manipulation rasps as trial stems . In this report , we compare 50 conventional total hip replacements with 50 procedures performed using the minimally invasive procedure  in terms of blood loss and the duration of the operation . The length of the skin incision varied between 7 and 12 cm with the minimally invasive technique , compared to 15 to 22 cm with the conventional procedure . Both groups were virtually identical with respect to average blood loss ( haemoglobin on 10th post-operative day : minimally invasive group , 108.0 g/L ; conventional group , 112.0 g/L ) and the duration of the procedure ( minimally invasive group , 60 minutes ; conventional group , 58 minutes ) . The position of the implanted components correlated with the pre-operative planning with regard to medial head offset , centre of rotation of the hip , and leg length , and was as satisfactory as that observed with the conventional procedure . The complication rate was low ( 2.9 % ) . Shaft fissures occurred in the first months of use of the minimally invasive procedure before adaptation of the shaft rasps . Dislocations were attributable to improper patient behaviour . Minimally invasive surgery via the anterolateral approach in the supine position was equivalent to the conventional procedure , had a low rate of complications , and did not adversely impact the technical success of the procedure BACKGROUND Minimally invasive total hip arthroplasty has stirred substantial controversy with regard to whether it provides superior outcomes compared with total hip arthroplasty performed through longer incisions . The orthopaedic literature is deficient in well- design ed scientific studies to support the clinical superiority of this approach . The objective of this study was to compare the results of a single mini-incision approach with those of a st and ard-incision total hip arthroplasty in the early postoperative period . METHODS Two hundred and nineteen patients ( 219 hips ) admitted for unilateral total hip arthroplasty between December 2003 and June 2004 were r and omized to undergo surgery through a short incision of < or=10 cm or a st and ard incision of 16 cm .  All patients were blinded to the size of the incision for the duration of the hospital stay . The anesthetic , analgesic , and postoperative physiotherapy protocol s were st and ardized , with the staff also blinded to the technique used . A single surgeon , who had performed more than 300 short-incision hip replacements prior to the start of this study and who performs an average of 415 primary total hip replacements a year , performed all procedures through a single-incision posterior approach using a cementless cup and cemented stem . RESULTS The two groups were matched for age , grade according to the system of the American Society of Anesthesiologists , and body mass index . No significant difference was detected with respect to postoperative hematocrit , blood transfusion requirements , pain scores , or analgesic use . We found no difference in early walking ability or length of hospital stay and no difference in component placement , cement-mantle quality , or functional outcome scores at six weeks . The patient variables significantly associated with a probability of early discharge independent of incision length were patient age and preoperative hemoglobin levels ( p < 0.05 ) . The surgical scars contracted significantly over six weeks ( p < 0.05 ) but by a similar proportion of 11 % to 12 % in both groups . CONCLUSIONS Minimally invasive total hip arthroplasty performed through a single-incision posterior approach by a high-volume hip surgeon with extensive experience in less invasive approaches to the hip is safe and reproducible . However , it offers no significant benefit in the early postoperative period compared with a st and ard incision of 16 cm . As it is not known whether lower-volume and less-experienced surgeons can achieve similar results , the mini-incision technique merits further study before wide dissemination and implementation of this family of surgical approaches can be recommended
These studies did not show a satisfactory overall survival rate
Background and purpose The aim of short-stem total hip arthroplasty is to preserve proximal bone stock for future revisions , to improve biomechanical reconstruction , and to make minimally invasive approaches easier .
It is therefore being increasingly considered to be a sound alternative to conventional total hip arthroplasty , especially for young and active patients .
However , it is still unknown whether survival rates of short-stem  hips match current st and ards .
We made a systematic summary of reported overall survival after short-stem total hip arthroplasty .