Outcomes of birmingham hip resurfacing: a systematic review

Birmingham hip resurfacing: a systematic review of outcomes at minimum 10-years follow-up

Although controversy surrounding the use of metal-on-metal (MoM) arthroplasty implants continues to exist, satisfactory clinical and radiological outcomes have been reported following Birmingham Hip Resurfacing (BHR) at long-term follow-up, leading to an Orthopaedic Data Evaluation Panel (ODEP) rating of 13A. The purpose of this study was to systematically review the literature to evaluate the functional outcomes, radiological outcomes and revision rates following BHR at a minimum of 10 years follow-up. Using the PRISMA guidelines, two independent reviewers performed a literature search using Pubmed, Embase and Scopus databases. Only studies reporting on outcomes of BHR with a minimum of 10 years' follow-up were considered for inclusion. A total of 12 studies including 7132 hips (64.8% males), with mean follow-up of 11.5 years (10-15.3), met our inclusion criteria. Of included patients, 94.3% of patient underwent BHR for osteoarthritis at a mean age was 52.0 years (48-52). At final follow-up, 96% of patients reported being satisfied with their BHR, with mean Harris Hip Scores of 93.6 and Oxford Hip Scores of 16.5. Rates of radiological femoral neck narrowing of greater than 10% and non-progressive radiological loosening were reported as 2.0% and 3.8% respectively. At final follow-up, the overall revision rate was 4.9% (334/7132), deep infection rate was 0.4%, metal allergy/insensitivity rate was 1.6%, metal reaction rate was 0.3%, rate of peri-prosthetic fracture was 0.9% and aseptic loosening rates were 1.6%. This systematic review demonstrates that BHR results in satisfactory clinical outcomes, acceptable implant survivorship, low complication rates and modest surgical revision rates in the long-term at minimum 10-year follow-up.

Birmingham Hip Resurfacing vs Total Hip Arthroplasty: A Matched-Pair Comparison of Clinical Outcomes

BACKGROUND

Birmingham hip resurfacing (BHR) has proven to be a good alternative for younger patients with osteoarthritis. Some have asserted that BHR may yield outcomes which are superior to total hip arthroplasty (THA), and that some studies which failed to show a difference were plagued by ceiling effects and lack of sensitivity of outcome measures. The purpose of this study is to compare outcomes of BHR and THA using the "Forgotten Joint" Score-12 (FJS), a more sensitive score with lesser vulnerability to the ceiling effect.

METHODS

Patients who underwent BHR were matched to patients who underwent posterior THA by computing a propensity score using 5 covariates: age, body mass index, gender, worker's compensation claims, and previous hip surgery. Surgical outcomes were assessed using 6 patient-reported outcome measures, including the FJS, the visual analog scale for pain, and patient satisfaction.

RESULTS

There were 42 patients in the BHR group and 18 patients in the THA group. The FJS was 78.0 for the BHR group and 76.0 for the THA group. The Veterans RAND 12-Item Health Survey Mental Component Summary and Short Form 12 Mental Component Summary were significantly higher in the BHR group. No differences were seen between all other patient-reported outcomes.

CONCLUSION

BHR offers excellent results in young patients that are comparable to THA. As no clinical difference could be shown between BHR and THA, even with the use of the FJS, the choice between BHR and THA should not be based solely on any expectation that either yields superior clinical outcomes compared to the other at short-term follow-up.

Mid-Term Results and Predictors of Patient-Reported Outcomes of Birmingham Hip Resurfacing

BACKGROUND

Birmingham hip resurfacing (BHR) is the only Food and Drug Administration approved resurfacing option currently available in the United States. While adequate BHR outcomes are established, there is a paucity of US-based literature demonstrating factors critical to improve patient reported outcomes (PROs). This study answers: (1) What is the implant survivorship in a large US cohort? (2) Which preoperative factors result in higher PRO scores over 5 years postoperatively?

METHODS

A retrospective 541 hip single-surgeon cohort with mean of 6.2 years follow-up (range 5-8.1) was collected. Preoperative patient/implant variables, including postoperative radiographic acetabular inclination and femoral component position, clinical outcomes, and follow-up PRO questionnaire information were collected. Validated PROs included the Hip Disability and Osteoarthritis Outcome Score (HOOS), Veterans Rand-12, and University of California Los Angeles (UCLA) activity. PROs were modeled with ordinary least squares then used to create nomograms.

RESULTS

Average patient age was 53 years with 391 (72%) males. Seven hips were revised, resulting in an overall survival of 98.8% at 5 years. Predictive modeling identified preoperative variables (sex, body mass index, smoking, and comorbidity) that had statistically significant associations with HOOS pain (P = .049), HOOS activities of daily living (P = .017), UCLA activity (P < .001), and Veterans Rand-12 physical (P < .001) PROs at latest follow-up. Nomograms predicted follow-up PROs using preoperative patient-specific variables.

CONCLUSION

This study documents excellent survival of the largest reported single-center cohort of BHRs in the United States with a mean 6.2 years follow-up. Multivariate modeling shows male nonsmokers with low body mass index, and no comorbidities will have less hip pain, better function in daily life, higher activity, and better general physical health after BHR arthroplasty.

Total hip replacement and surface replacement for the treatment of pain and disability resulting from end-stage arthritis of the hip (review of technology appraisal guidance 2 and 44): systematic review and economic evaluation

BACKGROUND

Total hip replacement (THR) involves the replacement of a damaged hip joint with an artificial hip prosthesis. Resurfacing arthroplasty (RS) involves replacement of the joint surface of the femoral head with a metal surface covering.

OBJECTIVES

To undertake clinical effectiveness and cost-effectiveness analysis of different types of THR and RS for the treatment of pain and disability in people with end-stage arthritis of the hip, in particular to compare the clinical effectiveness and cost-effectiveness of (1) different types of primary THR and RS for people in whom both procedures are suitable and (2) different types of primary THR for people who are not suitable for hip RS.

DATA SOURCES

Electronic databases including MEDLINE, EMBASE, The Cochrane Library, Current Controlled Trials and UK Clinical Research Network (UKCRN) Portfolio Database were searched in December 2012, with searches limited to publications from 2008 and sample sizes of ≥ 100 participants. Reference lists and websites of manufacturers and professional organisations were also screened.

REVIEW METHODS

Systematic reviews of the literature were undertaken to appraise the clinical effectiveness and cost-effectiveness of different types of THR and RS for people with end-stage arthritis of the hip. Included randomised controlled trials (RCTs) and systematic reviews were data extracted and risk of bias and methodological quality were independently assessed by two reviewers using the Cochrane Collaboration risk of bias tool and the Assessment of Multiple Systematic Reviews (AMSTAR) tool. A Markov multistate model was developed for the economic evaluation of the technologies. Sensitivity analyses stratified by sex and controlled for age were carried out to assess the robustness of the results.

RESULTS

A total of 2469 records were screened of which 37 were included, representing 16 RCTs and eight systematic reviews. The mean post-THR Harris Hip Score measured at different follow-up times (from 6 months to 10 years) did not differ between THR groups, including between cross-linked polyethylene and traditional polyethylene cup liners (pooled mean difference 2.29, 95% confidence interval -0.88 to 5.45). Five systematic reviews reported evidence on different types of THR (cemented vs. cementless cup fixation and implant articulation materials) but these reviews were inconclusive. Eleven cost-effectiveness studies were included; four provided relevant cost and utility data for the model. Thirty registry studies were included, with no studies reporting better implant survival for RS than for all types of THR. For all analyses, mean costs for RS were higher than those for THR and mean quality-adjusted life-years (QALYs) were lower. The incremental cost-effectiveness ratio for RS was dominated by THR, that is, THR was cheaper and more effective than RS (for a lifetime horizon in the base-case analysis, the incremental cost of RS was £11,284 and the incremental QALYs were -0.0879). For all age and sex groups RS remained clearly dominated by THR. Cost-effectiveness acceptability curves showed that, for all patients, THR was almost 100% cost-effective at any willingness-to-pay level. There were age and sex differences in the populations with different types of THR and variations in revision rates (from 1.6% to 3.5% at 9 years). For the base-case analysis, for all age and sex groups and a lifetime horizon, mean costs for category E (cemented components with a polyethylene-on-ceramic articulation) were slightly lower and mean QALYs for category E were slightly higher than those for all other THR categories in both deterministic and probabilistic analyses. Hence, category E dominated the other four categories. Sensitivity analysis using an age- and sex-adjusted log-normal model demonstrated that, over a lifetime horizon and at a willingness-to-pay threshold of £20,000 per QALY, categories A and E were equally likely (50%) to be cost-effective.

LIMITATIONS

A large proportion of the included studies were inconclusive because of poor reporting, missing data, inconsistent results and/or great uncertainty in the treatment effect estimates. This warrants cautious interpretation of the findings. The evidence on complications was scarce, which may be because of the absence or rarity of these events or because of under-reporting. The poor reporting meant that it was not possible to explore contextual factors that might have influenced study results and also reduced the applicability of the findings to routine clinical practice in the UK. The scope of the review was limited to evidence published in English in 2008 or later, which could be interpreted as a weakness; however, systematic reviews would provide summary evidence for studies published before 2008.

CONCLUSIONS

Compared with THR, revision rates for RS were higher, mean costs for RS were higher and mean QALYs gained were lower; RS was dominated by THR. Similar results were obtained in the deterministic and probabilistic analyses and for all age and sex groups THR was almost 100% cost-effective at any willingness-to-pay level. Revision rates for all types of THR were low. Category A THR (cemented components with a polyethylene-on-metal articulation) was more cost-effective for older age groups. However, across all age-sex groups combined, the mean cost for category E THR (cemented components with a polyethylene-on-ceramic articulation) was slightly lower and the mean QALYs gained were slightly higher. Category E therefore dominated the other four categories. Certain types of THR appeared to confer some benefit, including larger femoral head sizes, use of a cemented cup, use of a cross-linked polyethylene cup liner and a ceramic-on-ceramic as opposed to a metal-on-polyethylene articulation. Further RCTs with long-term follow-up are needed.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013003924.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.