Abstract
Introduction
Perthes' disease is associated with coxa breva, plana and magna, and a high riding prominent greater trochanter causing abductor shortening and weakness, leg shortening and extra-articular impingement. A trochanteric advancement with an infero-lateralising oblique sliding osteotomy of the proximal femur would lengthen femoral neck, improve abductor length and strength, relieve impingement and improve leg length. We assessed the mid-term outcomes for this procedure.
Method
We included patients who underwent the operation by the senior author (JNOH) with more than 2 years follow-up. The osteotomies were performed minimally invasively under image intensifier guidance and fixed with blade plate or locking plates. We assessed functional scores, radiological changes in neck length, Tonnis grading for arthritis and evidence of femoral head avascular necrosis, time interval for conversion to hip arthroplasty and associated complications.
Results
Twenty four patients (25 hips) underwent the procedure at mean age of 18.7 years (range:9.3–38.8) with a mean follow-up of 5 years (range:2–13.8). At the last assessment, the mean Oxford Hip Score was 41.6 (range:58–27), Non-Arthritic Hip Score was 53.4 (range:25–77) and UCLA activity score was 4.2 (range:2–6). For changes in neck length, the mean “Head-centre-to-Greater-trochanteric-tip-distance” was 60 mm (range:43–78) compared to 39 mm (range:30–48) pre-operatively and the mean “Head-centre-to-Lesser-trochanteric-tip-distance” was 54 mm (range:47–64) compared to 37 mm (range:31–41) pre-operatively. The mean Tonnis grade was 1.5 (range:1–3) compared to 1.3 (range:1–2) pre-operatively. Two patients underwent arthroplasty conversion at 2 and 13.8 years later. One patient needed head-neck debridement for impingement and 2 patients underwent trochanteric refixation for non-union. There were no cases of avascular necrosis.
Discussion
Symptomatic Perthes' hip deformity in adolescents and young adults is difficult to treat with joint preserving surgery. The mid-term clinical, functional and radiological results for double proximal femur osteotomy are encouraging.
