Bone remodelling around a cementless straight THA stem: a prospective dual-energy X-ray absorptiometry study

The design of the Bicontact® stem (BBraun, Aesculap, Tuttlingen, Germany) and the implantation technique have undergone no major alterations in the last 20 years leading, and good clinical results have been reported. The aim of our study was to investigate whether the implant encourages beneficial bone remodelling. Twenty-four patients were included in a prospective dual-energy X-ray absorptiometry (DEXA) study of this stem, after appropriate statistical power analysis. Preoperative and postoperative (1 week, 6 months, and 12 months) clinical and DEXA examinations were performed. The Harris Hip Score increased significantly by 39 points. The strongest decreases in BMD were observed in the greater trochanter region (-11%) and the calcar (-12%). In the second half of the study period the bone mineral density recovered slightly and even returned to baseline values in the lesser trochanter region. Therefore, proximal load transfer and physiological bone remodelling around the Bicontact® stem appeared to be achieved.