Metal-on-Metal vs Conventional Total Hip Arthroplasty : A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Metal-on-metal (MOM) hip articulations represent a potential alternative to conventional metal-on-polyethylene total hip arthroplasty (THA). We performed a systematic review of the peer-reviewed literature in search of studies comparing MOM with conventional primary THA with regard to functional outcomes, radiographic outcomes, and complication rates. Four Level I randomized controlled trials remained following our screening process. The data published in these studies were extracted and aggregated using a Mantel-Haenszel cumulative fixed effects meta-analysis. We found no significant difference between MOM and conventional THA with regard to functional outcomes as measured by Harris hip scores and radiographic outcomes as measured by radiolucent lines. Patients with MOM THA did however demonstrate a 3.37 times greater complication rate (1.57, 7.26). In light of the lack of superiority, the increased complication rate, the greater cost, and the potential for adverse medical consequences associated with MOM THA, these bearing surfaces should be used with caution.     

全髋关节置换术后病人健康相关生存质量评估

[目的]评价Harris评分在全髋关节置换术疗效评估中的局限性。[方法]对2005年9月~2006年1月47例(50髋)接受全髋关节置换术的病人进行6个月的前瞻性研究。在术前和术后6个月均对病人进行Harris评分和评估健康相关生存质量的SF-36简明健康状况调查量表(MOS36-item Short Form Health Survey,SF-36)评分,并分析Harris评分和SF-36各项评分之间的相关性。[结果]病人术后6个月的Harris评分和SF-36各项评分均较术前有统计学意义上的差异(P<0.001),但SF-36各项评分的改善程度并不一致。Harris评分和SF-36生理功能(PF)和躯体疼痛(BP)项评分有相关性(r>0.4,P<0.001),但与SF-36其它方面评分无明显相关性(r<0.4),或无相关性(P>0.05)。[结论]虽然Harris评分能较好地评估全髋关节置换术对改善病人生理功能和缓解疼痛的疗效,但对于评价病人健康相关生存质量和其它方面的改善还存在局限性。因此,有必要将SF-36评分引入到全髋关节置换术的疗效评估中。     

Functional outcomes for 2 years comparing hip resurfacing and total hip arthroplasty

This prospective observational study of 499 patients with hip resurfacing and 255 patients with total hip arthroplasty compared outcomes for 2 years. We used propensity scores to identify matched cohorts of 118 patients with hip resurfacing and 118 patients with total hip arthroplasty. We used these cohorts to compare improvements in the Western Ontario and McMaster University (WOMAC) osteoarthritis index and Medical Outcomes Short-Form 36 physical function component (SF-36 PF) scores at 3 months and at 1 and 2 years postsurgery. Both groups demonstrated significant improvements from baseline in WOMAC and SF-36 PF. Improvements in SF-36 PF were greater for patients with hip resurfacing than for patients with total hip arthroplasty 1 and 2 years postsurgery; improvements in WOMAC were similar for both groups. The clinical significance of this observation needs further investigation.     

Excellent Results and Minimal Complications of Total Hip Arthroplasty in Sickle Cell Hemoglobinopathy at Mid-Term Follow-Up Using Cementless Prosthetic Components

The purpose of this study was to compare the outcomes of cementless primary total hip arthroplasty (THA) in sickle cell patients compared to the remaining cohort of osteonecrosis patients who did not have this disease. Thirty-two sickle cell patients (42 hips) who had a mean age of 37 years and mean follow-up of 7.5 years (range, 5–11 years) were compared to 87 non-sickle cell osteonecrosis patients (102 hips) who had mean age of 43 years and mean follow-up of 7 years (range, 3–10.5 years). Outcomes evaluated included implant survivorship, Harris hip scores, complication rates, radiographic outcomes, and Short Form-(SF-36) health questionnaire. There were no significant differences in aseptic implant survivorship (95 vs. 97%), Harris hip scores (87 vs. 88 points), SF-36 score, or radiographic findings between the two patient cohorts. In light of these findings, we believe that the outcomes of THA improved in sickle cell patients with optimized medical management and the use of cementless prosthetic devices.     

Direct Cementation of Dual Mobility Cups Into the Bony Acetabulum in Primary Total Hip Arthroplasty: Clinical and Radiographic Outcomes at a Minimum 5-Year Follow-Up

BackgroundCemented dual mobility cups (DMCs) are commonly used in combination with acetabular reinforcement devices. Indeed, according to literature, direct cementation of metal-backed acetabular components into the bony acetabulum remains controversial as this technique is potentially associated with increased rates of aseptic loosening. Therefore, this study aimed to evaluate the clinical and radiographic outcomes of DMC cemented into the bony acetabulum in primary total hip arthroplasty (THA).MethodsA total of 49 THA (48 patients, mean age 78 years [range, 51 to 91]) performed with direct cementation of a DMC into the bony acetabulum were prospectively included in our total joint registry and retrospectively reviewed. The clinical outcome was assessed using the Harris hip score (HHS). The radiographic outcome included measurement of component positioning and occurrence and progression of demarcation around the cemented DMC. Complications were reported with a particular attention to cemented fixation failure and aseptic loosening.ResultsAt a 7-year mean follow-up (range, 5 to 8), the pre-to postoperative HHS improved from 47 (range, 30 to 58) to 92 points (range, 80 to 98) (P < .01). Nonprogressive and focalized demarcations were observed in 7 THA (14%). Importantly, no progressive demarcation or DMC aseptic loosening was observed.ConclusionDirect cementation of DMC into the bony acetabulum ensured a stable fixation with no progressive demarcation or aseptic loosening at midterm follow-up. Therefore, this technique can be selectively considered in primary THA, especially in elderly or frail patients to avoid potential mechanical failure of press-fit fixation due to altered bone quality or additional morbidity related to the use of acetabular reinforcement devices.     

Total hip arthroplasty in patients younger than 30 years of age following developmental dysplasia of hip (DDH) in infancy

Total hip arthroplasty (THA) in young patients is a controversial subject, due to the high failure rates reported in the literature, and even more so in patients with a history of developmental dysplasia of the hip (DDH). A group of 11 patients, all under the age of 30 years at the time of surgery, underwent THA due to congenital dislocation of the hip. Mean age at the time of operation was 23.3 years (range 16-30 years). The mean follow-up period was 9 years (range 3-14 years). The mean preoperative Harris' hip score (HHS) was 56.9 compared with the postoperative HHS of 90.6. Due to aseptic loosening of the cup, 4 patients underwent successful revision arthroplasty. These encouraging medium-term results in our patients suggest that THA may be a good solution for young patients suffering from coxarthrosis due to DDH, at least temporarily, especially when other alternatives, such as arthrodesis or resection arthroplasty, are considered.     

Levels of metal ions after small- and large-diameter metal-on-metal hip arthroplasty

Metal-on-metal (MOM) bearings for hip arthroplasty are increasing in popularity. Concern remains, however, regarding the potential toxicological effects of the metal ions which these bearings release. The serum levels of cobalt and chromium in 22 patients who had undergone MOM resurfacing arthroplasty were compared with a matched group of 22 patients who had undergone 28 mm MOM total hip arthroplasty (THA). At a median of 16 months (7 to 56) after resurfacing arthroplasty, we found the median serum levels of cobalt and chromium to be 38 nmol/l (14 to 44) and 53 nmol/l (23 to 165) respectively. These were significantly greater than the levels after 28 mm MOM THA which were 22 nmol/l (15 to 87, p = 0.021) and 19 nmol/l (2 to 58, p < 0.001) respectively. Since the upper limit for normal patients without implants is typically 5 nmol/l, both groups had significantly raised levels of metal ions. MOM bearings of large diameter, however, result in a greater systemic exposure of cobalt and chromium ions than bearings of small diameter. This may be of relevance for potential long-term side-effects. It is not known to what extent this difference is due to corrosion of the surfaces of the component or of the wear particles produced.     

比较人工全髋关节置换在治疗股骨头缺血性坏死和类风湿性关节炎中的作用

目的评估人工全髋关节置换（THA）在治疗股骨头缺血性坏死（AVN）和类风湿性关节炎（RA）中的作用。方法采用非骨水泥型THA治疗的42例（50髋）AVN和40例（50髋）RA患者,分别进行临床和影像学比较。临床随访包括Harris评分、术后翻修率和并发症分析;影像学评估包括骨溶解、聚乙烯臼杯磨损率分析。结果患者均获随访,时间5～10年。临床随访结果：AVN组和RA组Harris评分由术前（49.59±9.03）分和（48.76±7.61）分,术后分别提高到（90.76±5.64）分和（87.18±6.83）分,较术前均明显提高,但两组间Harris分值提高差异无统计学意义（P〉0.05）;AVN组和RA组术后翻修率分别为6%（3髋）和8%（4髋）,并发症分别为6%（3髋）和10%（5髋）,两组间差异无显著性（P〉0.05）。影像学结果：聚乙烯磨损率AVN组明显高于RA组,分别为（0.15±0.11）mm/年和（0.10±0.09）mm/年,两组比较差异有统计学意义（P〈0.05）;髋臼侧骨溶解发生率AVN组明显高于RA组,分别为18%（9髋）和4%（2髋）,两组比较差异有统计学意义（P〈0.05）;而股骨侧假体骨溶解发生率分别为20%和12%,两组比较差异无统计学意义（P〉0.05）。结论非骨水泥型THA在AVN和RA随访中均取得了良好的疗效,但AVN组髋臼侧聚乙烯内衬磨损和髋臼骨溶解高于RA组。     

Hip Osteonecrosis: Does Prior Hip Surgery Alter Outcomes Compared to an Initial Primary Total Hip Arthroplasty?

The purpose of this study was to assess the clinical and radiographic outcomes of total hip arthroplasty (THA) in patients who had osteonecrosis to see if prior hip preserving surgery affected outcomes. Implant survivorship, Harris hip scores, and radiographic outcomes were compared between 87 patients (92 hips) who had undergone prior hip preserving procedures and 105 patients (121 hips) who had only undergone THA. Patients were also sub-stratified into low- and high-risk groups for osteonecrosis. At a mean follow-up of 75 months, there were no significant differences in survivorship, clinical, and radiographic outcomes among the cohorts. Higher revision rates were associated with patients who were in the high-risk group. The authors believe that hip joint preserving procedures may not adversely affect the outcomes of later THA in patients with osteonecrosis.     

Early Return to Function After Hip Resurfacing : Is It Better Than Contemporary Total Hip Arthroplasty?

Our hypothesis was that return of function for young patients undergoing resurfacing total hip arthroplasty (THA) with metal-on-metal bearings or contemporary THA with ceramic bearings would be comparable. Results from 337 unilateral hip resurfacing patients were compared with results from 266 unilateral ceramic-on-ceramic THA patients. Early differences in Harris Hip Scores were observed, but all differences faded by 24 months. Hip resurfacing seems to be a viable alternative to THA for well-selected patients. However, the public perception of improved functional capabilities was not demonstrated in this patient population. Resurfacing patients may be more impaired (slightly higher pain scores/lower function scores) than their THA counterparts in the early postoperative period, but these differences disappear by 24 months when both groups report Harris Hip Scores in the excellent range.     

Mid-Term Outcomes of Dual Mobility Acetabular Cups for Revision Total Hip Arthroplasty

Background

This study evaluated (1) survivorship, (2) clinical outcomes, (3) complications, and (4) radiographic outcomes of dual mobility (DM) systems when compared to fixed-bearing prostheses in revision total hip arthroplasty (THA).

Early experience with the Depuy Proxima short stem in total hip arthroplasty

Bone saving hip athroplasty is a reasonable option for younger active patients, as they are potential candidates for subsequent revision arthroplasty. In this clinical and radiological study we have evaluated our first 41 consecutive cases of total hip arthroplasty including a DePuy Proxima short stem. Harris Hip Scores (HHS) were calculated preoperatively, and 6,12 and 24 months postoperatively. Mean age at surgery was 49 years (range : 35 to 60), mean follow-up was 26 months (range: 13 to 44). Mean Harris Hip scores increased by 39 and 50 points respectively at 6 and 24 months follow-up. No radiological loosening or migration was observed. In carefully selected young patients when resurfacing is contraindicated, use of the Proxima short stem appears as a simple and effective option for THA. However, longer follow-up time is required to analyse the results and to confirm the durability of the observed clinical out-comes.     

Outcome of hip resurfacing in obese patients

The effect of obesity on outcome for patients undergoing hip resurfacing has been evaluated. Pre and post-operative objective patient scored outcomes for a group of 181 cases of hip resurfacing performed over a three year period were collected. Cases have been stratified by body mass index (BMI) with evaluation of post-operative complications. Patient outcomes included: SF-36, WOMAC, and satisfaction scores, and were compared pre-operatively, and at one year. We found an increased rate of wound complications in the obese group (BMI > 30) with 4 cases of prolonged wound drainage and 2 superficial infections, compared to none in the non-obese group. A similar improvement in SF-36, WOMAC and patient satisfaction was found for both groups. No increase in the risk of femoral neck fracture or aseptic loosening was seen in the obese group. These results suggest excellent early outcomes for obese patients undergoing hip resurfacing with no added risk of early failure.     

术前功能对初次人工全髋关节置换术后早期功能的影响

[目的]探讨术前功能状态对初次全髋关节置换术(THA)术后早期功能的影响.[方法]对2006年1月-2008年1月期间在本科行初次非骨水泥型全髋关节置换的髋关节骨性关节炎95例患者进行随访研究,其中男49例,女46例,平均年龄62.7岁(50～76周岁),随访时间大于24个月.根据患者术前Harris评分(HHS)将患...     

Function and survival after revision of hip resurfacing

The purpose of this study was to compare functional outcome and survival of isolated acetabular, isolated femoral and both component revision after failure of primary Birmingham Hip Resurfacing. The Oswestry Outcome Centre prospectively collected data on 5000 hip resurfacing between 1997 and 2002. Of these, 182 hips were revised: 8% had revision of the acetabular component only, 42% had revision of the femoral component only to conventional stemmed prosthesis, and 50% had revision of both components to conventional total hip arthroplasty (THA). We used a postal questionnaire to assess function by Harris and Merle d'Aubigné and Postel hip scores and determined survival using re-revision as an endpoint. In patients with isolated acetabular revision, the median Harris hip score (HHS) was 74 at a mean of 4.5 years follow up. Isolated femoral revision had a median HHS of 82 at a mean of 3.8 years. When both components were revised, the median HHS was 85 at a mean of 4 years. We observed no difference in HHS between the groups. There was an average survival of 92% at 10 years. Survival was significantly lower for isolated acetabular revision (75%) than isolated femoral (93%) or both component revision (96%).     

Metal-on-metal hip resurfacing compared with total hip arthroplasty: two to five year outcomes in men younger than sixty five years

Purpose

There are limited studies examining the long-term survivorship for the current generation of metal-on-metal hip resurfacing (MOMHR) implants in the young male population, and fewer studies have been published on prospectively collected outcomes data for total hip resurfacing in the USA. The purpose of this study was to demonstrate the efficacy of MOMHR in comparison with total hip arthroplasty (THA) using validated outcome measures, survivorship and complication rates.

Methods

The study prospectively followed 136 implants in 123 male patients <65 years, all with a primary diagnosis of osteoarthritis and similar comorbidities as determined by the American Society of Anesthesiologists (ASA) score. A single-surgeon cohort of 89 MOMHRs was compared with a similar cohort of 47 THAs. Outcomes were prospectively assessed with the Short-Form Health Survey of 12 questions (SF-12) and Western Ontario and McMaster Universities (WOMAC) questionnaires pre- and postoperatively at yearly intervals. Minimum follow-up was two years, and average follow-up was 3.9 years.

Results

Diagnosis, body mass index (BMI), American Association of Anesthesiologists (ASA) and pre-operative pain and function scores were not significantly different between groups. There was no difference in SF-12 scores postoperatively. At one and two years postoperatively, the MOMHR group had better WOMAC scores than the THA group, but no difference was seen at three to five years postoperatively. There were no revisions in either group over the study period.

Conclusions

This study demonstrated good results for hip resurfacing in men <65 years five years postoperatively and similar function to THA patients.     

Outcome after total hip arthroplasty: Comparison of a traditional disease-specific and a quality-of-life measurement of outcome

The purpose of this study was to examine the relationship between the Harris Hip Score (HHS), a traditional method of patient assessment of a total hip arthroplasty (THA), and the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), a commonly used health-related quality-of-life survey. One hundred forty patients returning for routine clinical follow-up evaluation of a primary THA were asked to fill out the SF-36 quality-of-life survey, as well as questions concerning their perceptions of their THA. The patient's surgeon assessed the THA with the traditional HHS. The correlations between the HHS and the SF-36 domains were highest in the physical component summary scores for male patients of all ages and female patients 65 years of age or older. The correlations were lower for the mental component summary scores of all patients, but particularly in female patients younger than 65. When the SF-36 scores were compared with age and sex-matched population norms, both age and sex were found to be important. Men younger than 65 had scores lower than norms in the physical function domains, but were comparable in the mental health domains. The older men had scores comparable to the norms in all domains. Female patients of all ages, however, had lower scores in the physical function domains. The greatest differences were noted in the female patients younger than 65. The HHS is commonly used to assess disease-specific pain and function in THA patients; however, the results of this study suggest that the SF-36 health survey can capture additional important quality-of-life domains that are influenced by a THA and that these domains are influenced by the age and sex of the patient. The combination of a disease-specific scoring system and a quality-of-life survey would allow a more global assessment of a THA in all patients. Studies evaluating the results of THAs should either assess the results of male and female patients separately when sample size is sufficiently large or use sex as a possible covariate in a multivariate analysis.