Abstract
Introduction
Joint preserving procedures have gained popularity in an attempt to delay arthroplasty in young, dysplastic hips. Excellent results can be achieved with peri-acetabular osteotomy (PAO) in congruent non-arthritic hips. The role of salvage procedures such as the Shelf acetabuloplasty remains undefined. This study aims to determine the long-term survival and functional outcome following Shelf acetabuloplasty and to identify factors that influence outcome.
Patients/Materials & Methods
This is a retrospective, consecutive, multi-surgeon, case series from a UK referral centre. 125 Shelf procedures were performed between 1987–2013 on 117 patients for symptomatic hip dysplasia. Mean age was 33 years (15–53). Mean follow-up was 10 years (1–27). Radiographic parameters measured included pre-operative arthritis, acetabular-index, centre-edge-angle, joint congruency, subluxation and femoral sphericity. Oxford Hip and UCLA scores were collected at follow-up. Failure was defined as conversion to arthroplasty or OHS<20.
Results
The acetabular index and centre-edge angles have been improved from 23° (SD:9) and 12° (SD:8) pre-operatively to 10° (SD:9) and 45° (SD:11) post-operatively. By follow-up, 63 hips (50%) had converted to arthroplasty. The mean OHS and UCLA scores were 33 (SD:12) and 6 (SD:3), respectively. Survival rates were 82% at 5 years, 60% at 10 years and 43% at 15 years. The only factor influencing 10-yr survival was minimal pre-op arthritis (65% Vs 40%, p=0.02). Optimal functional outcome was seen when post-operative centre-edge angle was between 20–40° (p=0.01).
Discussion
This largest long-term series of Shelf acetabuloplasties reported to-date emphasises the value of this procedure in patients that pose treatment dilemmas as they are symptomatic, too young for arthroplasty but have features that make them unsuitable for PAO. Never-the-less, in 60% of cases a Shelf acetabuloplasty will delay arthroplasty for 10 years. If performed in patients with minimal arthritis and congruent joint 10-year survival is 85%.
Conclusion
Shelf acetabuloplasty is a simple, reliable procedure with good mid- to long-term results.
