Survival of Hydroxy Apatite-Coated Cups: Acetabular Screws Involve a Lower Rate of Revision Surgery due to Aseptic Loosening

Abstract

Background It is believed that the path of acetabular screws may represent a shuttle between hydroxyapatite (HA) particles and the liner. The aim was to assess the relationship between acetabular screws and revision surgery for aseptic loosening in total hip arthroplasties (THAs). Material and methods A retrospective multicentric study was performed. Patients older than 18 years and patients who underwent THA with both the stem and cup HA-coated were included. The rate of revision-surgery considering only aseptic loosening was calculated. The proportion of cases in which acetabular screws were used was registered, as well as the proportion of cups that showed osteolysis. The statistical relationship between acetabular screws and osteolysis, as well as acetabular screws and revision-surgery for aseptic loosening were assessed. Results There were 749 cases. Mean age 62.1 (45–84) years. Mean follow-up 14.19 (8.9-16.7) years. Revision surgery was performed in 12.8% (96/749) of the cups. 73.95% (71/96) of the revised cups showed aseptic loosening. The overall 15-year survival of the cups considering only aseptic loosening was 84.4%. Acetabular screws were used in 47.5% (356/749) of the cups. Acetabular screws were used in 40.44% (55/136) of the cups that showed osteolysis. The use of acetabular screws was associated with less osteolysis (p = 0.006). Acetabular screws were used in 35.21% (25/71) of the cups that were revised for aseptic loosening. The use of acetabular screws was associated with a lower rate of revision surgery (p = 0.020). Conclusions In THA with the stem and cup HA-coated, the use of acetabular screws is associated with a lower rate of revision surgery.