Archives of Orthopaedic and Trauma Surgery - 2026-08-22 - Journal Article
Hip resurfacing arthroplasty at a minimum of 14 years: revision is concentrated among female patients with dysplasia and small components.
Lin YC, Chang CH, Hsieh PH, Huang YY, Chen DW, Lau NC
Topics
Key Takeaway
HRA achieved 100% 15-year survivorship in primary OA and non-OA diagnoses, but DDH survivorship was 82.8%, with all five revisions occurring exclusively in female DDH patients receiving cups ≤50 mm.
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Summary
This single-surgeon retrospective study evaluated 15-year Kaplan-Meier survivorship of metal-on-metal HRA stratified by diagnosis (primary OA n=50, DDH n=29, non-OA n=25) performed 2006–2011. Overall 15-year survivorship was 95.2%; primary OA, non-OA, and AVN subgroups each achieved 100%, while DDH survivorship was 82.8% (p=0.002 vs. primary OA). All five revisions occurred in female DDH patients with cup size ≤50 mm, and Co/Cr ratios did not differ between groups (p=0.37), precluding attribution of failure to metal ion toxicity alone.
Key Limitation
The complete collinearity of DDH diagnosis, female sex, and cup size ≤50 mm in all revision cases prevents any multivariate determination of which factor drives failure, leaving the primary clinical question unanswered.
Original Abstract
INTRODUCTION
Hip resurfacing arthroplasty (HRA) is a bone-preserving option for young, active patients. The influence of the underlying diagnosis on long-term outcome remains unclear, particularly the distinction between primary osteoarthritis (OA), developmental dysplasia of the hip (DDH) and non-OA conditions.
MATERIALS AND METHODS
We retrospectively reviewed 104 consecutive metal-on-metal HRAs in 101 patients (three bilateral) performed by one surgeon between 2006 and 2011, stratified into Primary OA (n = 50), DDH (n = 29) and Non-OA (n = 25: avascular necrosis [AVN] n = 15, inflammatory arthritis n = 5, post-traumatic arthritis n = 3, Legg-Calvé-Perthes disease n = 2). AVN was analysed additionally as an independent group, and exploratory analyses restricted to female patients and to cups ≤ 50 mm addressed the collinearity of dysplasia, sex and size. Survivorship used Kaplan-Meier estimation with revision as the endpoint.
RESULTS
Implant status was known for all 104 hips; the 91 unrevised assessed hips had a mean follow-up of 16.2 ± 1.5 years. Overall 15-year survivorship was 95.2%. Primary OA, Non-OA and AVN each showed 100%; DDH 82.8% (versus Primary OA p = 0.002, versus Non-OA p = 0.031). All five revisions occurred in female DDH patients with a cup ≤ 50 mm; DDH survivorship remained lower within female patients (p = 0.025) and within small cups (p = 0.006), with no event in any comparator arm. Final HHS was lower in DDH (89.5 ± 8.5) than in Primary OA (93.9 ± 6.8) or Non-OA (95.0 ± 4.9; p = 0.012), a difference below the minimal clinically important improvement threshold of 15.9 to 18 points. The Co/Cr ratio did not differ between groups (p = 0.37).
CONCLUSIONS
HRA achieved 100% 15-year survivorship in primary OA and in non-OA diagnoses including AVN. Dysplasia may be associated with an increased risk of revision, but dysplasia, female sex and small component size were too collinear, with no revision outside the dysplastic group, for their independent contributions to be separated.