O2482 DENSITOMETRIC ASSESSMENT OF PERIPROSTHETIC BONE FOLLOWING CEMENTLESS TOTAL HIP REPLACEMENT: 10 YEARS FOLLOW UP

Abstract

Aims: to evaluate the process of remodelling at the bone-femoral prosthesis interface by using computerized bone mineralometry (CMB)Methods: at the Orthopaedic Clinic, University Catania we performed from January 1992 densitometric studies on uncemented, anatomically shaped, titanium stems with or without hydroxyapatite (HA) coating. Dual energy X-ray densitometry was used to quantify bone mineral concentration and bone mineral density (BMD). Measurements were performed at the calcar and the medial and lateral cortical of the femur which have been previously demonstrated to be areas of stresses transmission in the normal hip. From 1992 to 2001, 148 patients were regularly studied. 76 subjects had a HA-coating stem. Evaluation was performed at 3, 6 and 12 months after operation and then yearly. Results: in all patients a minimal remodeling process (BMD values > 1 gr/cm² ) was observed at the medial cortical and the calcar zones. We noted higher BMD values in the group with HA-coating stem within 24 months after the operation; BMD values were overlapping between the two groups after 24 months. 27 subjects had reduced densitometric values at the calcar and increased BMD at medial and lateral cortical. Conclusions: CMB appears to be a reliable tool to evaluate the interaction at the bone-femoral prosthesis interface. Densitometric values might be helpful to monitor the periprosthetic bone-remodelling process.