Conservative hip arthroplasty with resurfacing of the acetabulum and femoral head is an attractive concept particularly in young and active patients. The natural anatomy, joint biomechanics and stability are all preserved. Non -violation ofthe proximal femur, retention of tlte upper femoral bone stock and avoidance of stress shielding in the proximal femur are unique advantages. Unique disadvantages are the potential for failure from femoral neck fracture and collapsed femoral heads from avascular necrosis or osteolysis.
Patients and Methods
From July 2005 to April 2010, 38 Birmingham /tip resurfacings were done in 32 patients; 20 males and 12 females (6 cases with bilateral affection) with a mean age 43.4 years (range 25 56). Patients were clinically scored with the Harris Hip Score, hip range of movements and activity level. The mean pre-operative HHS was 37 (range 25-50). The follow -up period ranged from 6 months up to 5 years (range 2.5 years). All radiographs were evaluated pre-and postoperatively and at regular follow -up visits for osteolysis, reactive and radiolucent lines, bone remodeling, bone resorption or component migration.
At the most recent follow-up, 84.2% had ItO pain. The HHS averaged 91.8 (range 75-98). Seventy four percent of patients performed strenuous activities. Hip flexion averaged 120° (range 80° -142°). The final clinical results were excellent in 68.4% of patients, good in 21.1%, fair in 10.5% with no poor cases. Regarding the radiological results, a slight valgus placement of the head component is aimed for. The mean pre-operative allgle of the femoral neck was 133.5° which improved to 136.9° post-operatively. III tlte full series, lom.elling. osteolysis, reactive lilles or migration of the component was not seen ill allY of cases. There were infrequent complications mainly superficial wound infectioll in 3 cases and heterotopic o.'isification ill 2 cases.
Hip resurfacing is not a panacea for all hip art/iritis. It works well in young patients with good quality femoral head bone and a reaSOIIable proximal femoral anatomy. Tlte Birmingham Hip Resurfacing, when performed well in properly selected patients, continUl! to demonstrate excellellt outcomes.