We present our experience from use of acetabular reinforcement rings in revision total hip arthroplasty when bone defects are present. From 1987 to 2000, acetabular reinforcement rings were utilized in 59 revisions, in 52 patients with a mean age of 60 years (31–81). In 48 hips, Ganz rings were used and in 11 hips, Burch-Sch-neider rings. For the existing defects of the acetabulum, morsellized bone allograft was used. The patients were evaluated clinically with the modified Merle d’ Aubigne-Postel scale and radiologically with the criteria of Gill-Sledge-Muller. Acetabular reconstruction was successful in 51 of 59 hips (86.5%) after a mean follow-up period of 7 years (2–15). One of the 11 Burch-Schneider rings failed (9.1%) and 7 of the 48 Ganz, raising the failure rate of this ring up to 14.6%. Complications included dislocation in 5 cases, deep vein thrombosis in 2, superficial infection in 1 and pubis rami fracture in 2 cases. Reinforcement rings in our opinion could be of valuable help in reconstruction of the bone deficient acetabulum. Although in this study, it is not possible for these two rings to be directly compared, Burch-Schneider one appears to have a more clear role and lower failure rate. However, in order to evaluate in a more reliable way the true fate of the acetabular reinforcement rings, especially in the presence of the limited role of biological fixation, longer follow-up time is needed.
We followed up 76 consecutive hips with symptomatic acetabular dysplasia treated by acetabular shelf augmentation for a mean period of 11 years. Survival analysis using conversion to hip replacement as an end-point was 86% at five years and 46% at ten years. Forty-four hips with slight or no narrowing of the joint space pre-operatively had a survival of 97% at five and 75% at ten years. This was significantly higher (p = 0.0007) than that of the 32 hips with moderate or severe narrowing of the joint-space, which was 76% at five and 22% at ten years. There was no significant relationship between survival and age (p = 0.37) or the pre- and post-operative centre-edge (p = 0.39) and acetabular angles (p = 0.85). Shelf acetabuloplasty is a reliable, safe procedure offering medium-term symptomatic relief for adults with acetabular dysplasia. The best results were achieved in patients with mild and moderate dysplasia of the hip with little arthritis.