Ten-year clinical, radiological and metal ion analysis of the Birmingham Hip Resurfacing

Abstract

We present the clinical results and survivorship of consecutive 100 Birmingham Hip Resurfacings in 90 patients at a minimum follow-up of ten years. All procedures were carried out by an independent surgeon who commenced a prospective study in 1998. Patients were assessed clinically using the Western Ontario and McMaster Universities osteoarthritis index, Short-Form 36, Harris hip score and University of California, Los Angeles activity score. Radiological analysis was performed by an independent observer and blood metal ion levels concentrations were measured at ten years post-operatively in 62 patients. The median acetabular component inclination was 46.2° (34° to 59°) and anteversion 11.0° (0° to 30°). The median chromium concentration in the unilateral group was 1.74 (0.41 to 15.23) and for the bilateral group was 2.98 (1.57 to 18.01). The equivalent values for cobalt were 1.67 (0.54 to 20.4) and 1.88 (1.38 to 19.32). In total there were eight failures giving an overall survival at ten years of 92% (95% confidence interval (CI) 86.7 to 97.3). BHR in male patients had an improved survivorship of 94.6% (95% CI 89.4 to 100) compared with females at 84.6% (95% CI 70.7 to 98.5), but this did not reach statistical significance (p = 0.119). Four of the nine BHRs with a bearing diameter of 42 mm failed. The overall results were consistent with data produced from other centres in that the clinical outcome of large male patients was extremely encouraging, whereas the survival of the smaller joints was less satisfactory.

Survival and functional outcome of the Birmingham Hip Resurfacing system in patients aged 65 and older at up to ten years of follow-up

“…Good survival and functional outcome is reported for hip resurfacing in young patients at up to ten years of follow-up by both designer surgeons [1][2][3] and independent centres [4][5][6][7][8][9][10][11]. It was previously advised that elderly patients, typically ≥65 years, should not be considered for hip resurfacing [12,13].…”

Frequent Femoral Neck Osteolysis With Birmingham Mid-head Resection Resurfacing Arthroplasty in Young Patients

“…Only one case (3%) in our cohort had metal ion levels higher than the MHRA's cutoff level of 7 ppb [37]. Given the small numbers in our cohort, and comparing our 3% prevalence of exceeding the 7-ppb threshold to the 5% prevalence reported in the BHR followup study by Holland et al [27], no remarkable difference can be seen bearing in mind that the bearing surfaces of both devices have identical characteristics [13,35] and that the BMHR has an additional potential source of metal ions: the modular head-stem junction.…”

“…Patients' median OHS (using the 48-point OHS) improved from 26 (range, [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] preoperatively to 46 (range, [35][36][37][38][39][40][41][42][43][44][45][46][47][48], and UCLA score improved from 5 (range, 2-8) to 8 (range, 4-10) at latest review (paired t-test p \ 0.001 for both). There was no difference in median [35][36][37][38][39][40][41][42][43][44][45][46][47][48] or in the median postoperative UCLA scores between males (8; range, 5-10) and females (8; range, 4-10) (Mann-Whitney U p = 0.293 and p = 0.115, respectively).…”

Letter to the Editor: The Withdrawn ASR™ THA and Hip Resurfacing Systems: How Have Our Patients Fared Over 1 to 6 Years?

“…Such statements can be made only after demonstration that all devices from a class are outperformed by all devices from another and such a result is unlikely. In addition, there are at least five recent publications showing Kaplan-Meier survival estimates of metal-on-metal hip resurfacing devices ranging from 94.6% to 99% at 10 years in male patients [2,4,6,7] or patients with large femoral components sizes [1]. If progress is going to be made in the field of hip arthroplasty, is it not time surgeons begin to treat patients as individual cases rather than with a ''one device fits all'' policy?…”