Influence of preoperative bone mass density in periprosthetic bone remodelling after implantation of ABG-II prosthesis: A 10-year follow-up ☆

Abstract Introduction Preoperative bone mass index has shown to be an important factor in peri-prosthetic bone remodelling in short follow-up studies. Material and methods Bone density scans (DXA) were used to perform a 10-year follow-up study of 39 patients with a unilateral, uncemented hip replacement. Bone mass index measurements were made at 6 months, 1 year, 3 years, 5 years, and 10 years after surgery. Pearson coefficient was used to quantify correlations between preoperative bone mass density (BMD) and peri-prosthetic BMD in the 7 Gruen zones at 6 months, 1 year, 3 years, 5 years, and 10 years. Results Pre-operative BMD was a good predictor of peri-prosthetic BMD 1 year after surgery in zones 1, 2, 4, 5 and 6 (Pearson index from 0.61 to 0.75). Three years after surgery it has good predictive power in zones 1, 4 and 5 (0.71–0.61), although in zones 3 and 7 low correlation was observed 1 year after surgery (0.51 and 0.57, respectively). At the end of the follow-up, low correlation was observed in the 7 Gruen zones. Sex and BMI were found to not have a statistically significant influence on peri-prosthetic bone remodelling. Conclusion Although preoperative BMD seems to be an important factor in peri-prosthetic remodelling 1 year after hip replacement, it loses its predictive power progressively, until not being a major factor in peri-prosthetic remodelling 10 years after surgery.