THA with the ABG I Prosthesis at 15 Years: Excellent Survival with Minimal Osteolysis

Following recent reports of poor results with the hydroxyapatite-coated ABG I prosthesis, we report the survival of a series of 63 patients (69 hips) at a mean of 15 years (range, 13–17 years). In total, eight patients had revision procedures. The reason for revision was acetabular loosening in all cases. In only one case was there associated clinical and radiographic loosening of the femoral stem. The 15-year survival of the acetabular component was 86.9% (95% confidence interval, 71.7%–96.0%) and the 15-year survival of the femoral component was 98.6% (95% confidence interval, 88.8%–100.0%). Periacetabular osteolysis was seen in 10 of 59 (17%) surviving hips. In these hips the components remained well fixed owing to the remaining bone-component contact. There was no difference in the Oxford hip score between patients with well-fixed hips and evidence of osteolysis and patients with hips without evidence of osteolysis. Multivariate analysis failed to reveal any factors associated with the presence of osteolysis (gender, age at primary surgery, Oxford hip score, cup abduction, and acetabular polyethylene wear rates). The ABG I prosthesis continues to show excellent long-term results. Ongoing radiographic review is recommended to detect progressive osteolysis that otherwise remains clinically silent until failure.