The next critical role of orthopedic registries A comparison of total hip resurfacing and total hip arthroplasty - patients and outcomes. Excellent results with cementless total hip arthroplasty and alumina-on-alumina pairing: minimum ten-year follow-up Effect of pamidronate in preventing local bone loss after total hip arthroplasty: a randomized, double-blind, controlled trial. Cobalt and chromium levels in blood and urine following hip resurfacing arthroplasty with the Conserve Plus implant. The Charnley versus the Spectron hip prosthesis: clinical evaluation of a randomized, prospective study of 2 different hip implants. Two-year migration results of the ReCap hip resurfacing system—a radiostereometric follow-up study of 23 hips A randomised controlled trial of total hip arthroplasty versus resurfacing arthroplasty in the treatment of young patients with arthritis of the hip joint Long term results of the Corin C-Fit uncemented total hip arthroplasty in young patients Bone remodelling around the Metha short stem in total hip arthroplasty: a prospective dual-energy X-ray absorptiometry study
There is an urgent need for the introduction of new implant technology in orthopedic surgery to be conducted in a more controlled manner than in the past . Inadequate regulation and lack of effective post-market surveillance have meant that patients have not been protected from potentially harmful implants and procedures . Compounding the problem is a lack of question ing , a lack of critical appraisal , and lack of a requirement for clinical evidence by both surgeons and manufacturers before large-scale introduction of new technology to the market . There is a long and growing history of failed innovation , demonstrated by the failure or recall of individual products such as Boneloc ( bone cement ) , The Capital Hip ( total hip arthroplasty ) , and the ASR hip system ( total hip arthroplasty ) among others , as well as whole classes of devices such as large-head metal-on-metal bearings . This demonstrates simple , yet severe flaws in the mechanisms that should protect patients from increased risk associated with introduction of new technology . Insufficient or inadequate pre clinical data , a lack of clinical data from timely RSA ( radiostereometric analysis ) studies , and limited larger , multicenter cohort studies prior to general release all increase the risk to patients . The 510k process , where the majority of so-called innovative new design s have been cleared or approved by FDA - or CE-notified bodies for clinical use , is based on similarities to previously used implants . In the 510k process , there is no requirement for specific clinical evidence , so manufactures have not obtained clinical data . Registry post-market surveillance has proven to be a powerful method for detection of increased risk of implant failure , but this is not available in all countries . When registries do identify poor-performing devices , regulators and manufacturers are often slow to respond . The main problem with the current approach to the introduction of new technology is the inability to identify unanticipated failures before wider release ( Bauer 1992 ) . It is 20 years since the stepwise introduction of new implants was first described ( Malchau 1995 ) . The basic concept of this approach is that the smallest possible numbers of patients ( after sufficient pre clinical testing ) are exposed to the implant prior to general release . Stepwise introduction uses a combination of ( 1 ) outcome measurements with high-precision metrics in small cohorts , such as RSA , and ( 2 ) limited clinical introduction in a larger cohort , prospect ively monitoring outcomes and revisions . Adoption of this concept would certainly have reduced the large number of poor-performing new implants introduced in recent years . The concept has , however , never been implemented due to lack of support from surgeons , manufacturers , and regulatory authorities . Now trends have changed , with increasing focus on implementing an effective approach to pre-release clinical assessment . The ongoing work and discussion s in the International Society of Arthroplasty Registries ( ISAR ) , the reports from the Australian Orthopaedic Association total joint registry , and the actions taken in the UK to put a “ beyond compliance ” program into action will facilitate a more cautious market introduction . In addition , the Arthroplastywatch project ( www.arthroplastywatch.com ) is in action : data are collected on the web through a specially developed search routine . Based on examination in several steps using medical and statistical expertise , a caution could be warranted or a warning declared . These combined initiatives say one thing : that close monitoring of new implants by well-established registries during a phase of controlled introduction must be a universal requirement . We propose a structured model for clinical trials involving 4 levels : ( 1 ) a pure observational study using reoperation data from multiple registries , as shown in several papers by the Nordic Arthroplasty Register Association ( NARA ) ; ( 2 ) patient-reported outcome measures , either from national implant registries or from other registries for specific studies ; ( 3 ) radiographic data plus other parameters such as blood levels of metal ions , based on specific needs for a new technology ; and ( 4 ) options for r and omized studies with use of , for example , RSA in the evaluation . The cornerstone in this structural model should be the exp and ed use of existing and future registries with a high degree of coverage and completeness . While registries have a strong tradition in arthroplasty surgery , this is not as well developed in other areas of orthopedic surgery . It is the responsibility of orthopedic surgeons and their professional bodies to support and implement registries where they can be of benefit . The arthroplasty registry experience has shown that it is possible to use registries to effectively monitor the introduction of new technology . Without this registry-based surveillance , identification of many of the failed innovations would have been delayed or might even have gone unrecognized . It is encouraging that registries in fracture surgery are now emerging , where implants are inserted in large and increasing numbers . Finally , implant performance is potentially confounded by the technical difficulty of inserting the implant , the knowledge and abilities of the surgeon inserting them , and the complexity of the cases . Many registries monitor performance at the surgeon level . This together with continuous education and training in how to use new implants should be an integral part of the process of a more cautious market introduction . If training is linked in with the stepwise introduction , it will be possible to identify the need for and the extent of training . Our proposed regulatory change to require registry-based monitoring of new implants during the phase of limited introduction must be accompanied by a change in the way we think and act as orthopedic surgeons . In the training of future orthopedic surgeons , emphasis must be placed on developing a healthy skepticism to innovation , on recognizing the need for evidence -based introduction , and on building a culture holding the view that reporting to a registry is imperative . The registries will then be able to offer back data to enable surgeons to choose the best clinical practice . To increase innovation and to ensure that innovation is effective and beneficial , the role of registries should be exp and ed . The registries should not undertake the role of a regulatory authority , but in compliance with the industry and the orthopedic community they should ensure that a more cautious approach is used when new technology is introduced . This could lead to a better balance between the inborn conservatism that a registry represents and the continuous need for innovation . The independence , infrastructure , and expertise of the registries can be used more fully to optimize how new implants are introduced . All stakeholders need to join to ensure that first and foremost , we do no harm A comparison of pertinent preoperative and postoperative data relative to total hip resurfacing versus total hip arthroplasty ( THA ) would assist in evaluating current perceptions in outcome . We compared 50 consecutive metal-metal resurfacing replacements in 50 patients with 44 consecutive conventional total hip arthroplasties in 35 patients , who were implanted during the same time period , by the same surgeon , and followed prospect ively for 2 to 4 years . The patients undergoing hip resurfacing were 62 % male , 9 years younger , and 3.2 inches taller , with a lower mean body mass index and American Society of Anesthesiologists ( ASA ) grade than patients undergoing total hip arthroplasty .  Preoperatively , patients undergoing resurfacing had a lower Harris hip score ( 46 vs 52 points ) , more pain , higher UCLA ( University of California at Los Angeles ) activity scores ( 4.2 vs 3.6 ) , and better range of motion . Surgical time for resurfacing was 18 % longer , but there was less total blood loss and fewer transfusions . Postoperatively , there was no difference in Harris hip score ( 97 vs 96 ) . Patients undergoing resurfacing had higher function , Short Form-12 physical activity scores , and UCLA activity scores , but also a higher incidence of slight or mild pain . There were no differences in postoperative range of motion or dislocation ( one each ) . The preoperative characteristics and general health status of the average patient undergoing resurfacing are more favorable than that of the average patient undergoing conventional total hip arthroplasty . Caution should be applied in attributing differences in outcomes directly to the arthroplasty technology Ceramic-on-ceramic coupling is thought to be a durable alternative to metal- or alumina-on-polyethylene pairing . No evidence exists suggesting superior clinical and radiological results for hydroxyapatite-coated stems versus uncoated stems . The aim of this study is to report the performance of an alumina-on-alumina bearing  cementless total hip arthroplasty and to compare stems with a tapered design with and without hydroxyapatite coating . We prospect ively analysed the results of  cementless tapered femoral stems ( 40 hydroxyapatite-coated versus 22 uncoated stems ) , a metal-backed fibre mesh hydroxyapatite-coated socket and alumina-on-alumina pairing .  Of 75 hips studied , 62 were available for follow-up ( mean of 10.5 years after surgery ) . The average Harris hip score was 90 . Only one hydroxyapatite-coated stem was revised for aseptic loosening . One instance of non-progressive osteolysis was detected around a screw of a cup . All other components showed radiographic signs of stable ingrowth .  Hydroxyapatite coating of the stem had no significant impact on the clinical or radiological results . Total hip arthroplasty with the presented implant and pairing provides a durable st and ard for all patients requiring hip joint replacement against which all newer generations of cementless implants should be judged Acute periprosthetic bone loss occurs after total hip arthroplasty . Bone loss undermines the support of the implant and may contribute to prosthetic failure . At present , there is no established prophylaxis for this process . We studied the effect of a single-dose infusion of 90 mg of pamidronate on early periprosthetic bone mineral density ( BMD ) , biochemical markers of bone turnover , radiological , and clinical outcome in a 26-week , prospect i ve , r and omized , double-blinded study of 47 men and women undergoing total hip arthroplasty .  Pamidronate therapy led to a significant reduction in bone loss compared with placebo for both the proximal femur and the pelvis ( repeated measures analysis of variance [ ANOVA ] ) ; p = 0.001 and p = 0.01 , respectively ) . Pamidronate therapy was associated with suppression of all biochemical markers of bone turnover compared with placebo ( repeated measures ANOVA ; p < 0.05 for all comparisons ) , with the exception of urinary free deoxypyridinoline . Pamidronate did not interfere with the clinical improvement in symptoms after total hip arthroplasty , or radiological outcome , and was not associated with an increase in adverse events . This study provides clinical data on the efficacy and safety of bisphosphonates for the prevention of bone loss after total hip arthroplasty and supports the establishment of larger-scale clinical trials to determine the long-term clinical efficacy of this intervention using implant failure as the primary endpoint BACKGROUND The purpose of the present study was to determine cobalt and chromium ion levels in the blood and urine of patients in whom a modern-generation metal-on-metal hip resurfacing device had been implanted . METHODS A total of ninety-seven patients with a Conserve Plus metal-on-metal hip resurfacing implant  were followed prospect ively for two years . Cobalt and chromium levels in erythrocytes , serum , and urine were measured preoperatively as well as three , six , twelve , and twenty-four months postoperatively . RESULTS The median serum cobalt and chromium ion levels were 1.04 μg/L ( range , 0.31 to 7.42 μg/L ) and 2.00 μg/L ( range , 0.28 to 10.49 μg/L ) , respectively , at one year after surgery and 1.08 μg/L ( range , 0.44 to 7.13 μg/L ) and 1.64 μg/L ( range , 0.47 to 10.95 μg/L ) , respectively , at two years after surgery . The corresponding mean levels ( and st and ard deviations ) of serum cobalt and chromium were 1.68 ± 1.66 μg/L and 2.70 ± 2.22 μg/L , respectively , at one year after surgery and 1.79 ± 1.66 μg/L and 2.70 ± 2.37 μg/L , respectively , at two years after surgery . CONCLUSIONS These levels compare favorably with other published ion results for metal-on-metal hip resurfacing and replacement implants . No pseudotumors or other adverse soft-tissue reactions were encountered in our study population . Further research is needed to determine the clinical importance of increased cobalt and chromium ion levels in serum and urine following metal-on-metal hip resurfacing Prospect i ve , r and omized studies must be performed when new surgical techniques or implants are evaluated . In this study , a new implant system was compared with the Charnley prosthesis , which over the years has been the most used hip implant in Sweden . Between 1985 and 1989 , 410 hips were r and omized to treatment with a Charnley or a Spectron total hip arthroplasty : 206 Charnley and 204 Spectron prostheses were implanted . The patients were operated on by a st and ardized procedure using a contemporary cementing technique . The patients were followed prospect ively by an independent observer after 1 , 3 , 5 to 6 , and 10 years . Harris Hip Score and patient satisfaction were recorded in the outcome evaluation . A total of 144 patients with 164 hips were deceased , and 15 patients ( 8 Charnley and 7 Spectron ) have required a revision . Nine hips were revised because of aseptic loosening ( 5 Charnley stems and 4 Spectron metal-backed cups ) . The Charnley stem as well as the metal-backed Spectron cup had a higher risk for revision because of aseptic loosening . The Charnley ogee cup and the Spectron stem have performed remarkably well with no revision of these components . Seven Charnley prostheses dislocated , but no dislocation was recorded in the Spectron group . Survivorship calculations with a mean follow-up of 10 years revealed an overall 11-year survivorship of 94.5 % + /- 3.4 % ( Charnley , 93.2 % + /- 5.8 % ; Spectron , 95.9 % + /- 3.0 % ) . The clinical outcome did not differ between the 2 systems . The overall results in this old population , using a contemporary surgical technique , illustrate that cemented hip arthroplasty is an excellent treatment alternative for elderly patients There has been renewed interest for metal-on-metal hip resurfacing due to improved design and manufacturing of implants , better material s , and enhanced implant fixation . In contrast to conventional total hip replacements , only a few clinical hip resurfacing trials using radiostereometry ( RSA ) have been reported , and solely for the Birmingham hip resurfacing arthroplasty . The purpose of this RSA trial was to describe the migration pattern of a  new hip resurfacing system ( ReCap ) within the first two years after primary surgery . Twenty-six patients underwent total hip replacement .  The patients were followed-up for up to 24 months and were evaluated with the use of radiostereometric measurements .  The prosthesis showed mean translations and rotation close to zero . Maximum translation was seen along the transverse axis in the medial direction ( 0.13 mm ) . No statistically significant translation or rotation was seen at two-years follow-up , ( t-test , p < 0.05 , translation or rotation ) Background Hip replacement ( arthroplasty ) surgery is a highly successful treatment for patients with severe symptomatic arthritis of the hip joint . For older patients , several design s of Total Hip Arthroplasty have shown excellent results in terms of both function and value for money . However , in younger more active patients , there is approximately a 50 % failure rate at 25 years for traditional implants . Hip resurfacing is a relatively new arthroplasty technique . In a recent review of the literature on resurfacing arthroplasty it was concluded that the short-term functional results appear promising but some potential early disadvantages were identified , including the risk of femoral neck fracture and collapse of the head of the femur . The aim of the current study is to assess whether there is a difference in functional hip scores at one year post-operation between Total Hip Arthroplasty and Resurfacing Arthroplasty . Secondary aims include assessment of complication rates for both procedures as well cost effectiveness . Methods / design All patients medically fit for surgery and deemed suitable for a resurfacing arthroplasty are eligible to take part in this study . A r and omisation sequence will be produced and administered independently . After consenting , all patients will be clinical ly review ed and hip function , quality of life and physical activity level will be assessed through question naires . The allocated surgery will then be performed with the preferred technique of the surgeon . Six weeks post-operation hip function will be assessed and complications recorded . Three , six and 12 months post-operation hip function , quality of life and physical activity level will be assessed . Additional information about patients ' out-of-pocket expenses will also be collected . Trial registration Current Controlled Trials IS RCT N33354155UKCLRN portfolio ID Introduction We conducted a prospect i ve study to evaluate the long-term results after Corin C-Fit uncemented total hip arthroplasty in young patients with hydroxyapatite or porous coated components . Material s and methods We prospect ively followed 36 patients ( 38 hips ) who had Corin C-Fit uncemented total hip arthroplasties by eight experienced consultant surgeons at two centres . The acetabular and femoral components were hydroxyapatite or porous coated . Results The overall 10-year survival rate for the Corin C-Fit arthroplasty was 43 % . The 10-year survivorship for the femoral implant was 56 % and for the acetabular component 59 % . Conclusion The evidence presented in this study suggests that the Corin C-Fit uncemented total hip arthroplasty has one of the highest mid- and long-term failure rates for both femoral and acetabular components in the literature . We believe this implant should not be used and patients who have had this form of total hip arthroplasty should be kept under regular review 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
Patient Reported Outcome Measures ( PROMs ) at six months have been investigated but have not been vali date d against long-term outcomes .
EBRA can be used to investigate acetabular wear but not femoral migration .
OBJECTIVES High failure rates of metal-on-metal hip arthroplasty implants  have highlighted the need for more careful introduction and monitoring of new implants and for the evaluation of the safety of medical devices .
The National Joint Registry and other regulatory services are unable to detect failing implants at an early enough stage .
We aim ed to identify vali date d surrogate markers of long-term outcome in patients undergoing primary total hip arthroplasty ( THA ) .