Bone remodelling around HA-coated acetabular cups : a DEXA study with a 3-year follow-up in a randomised trial

Abstract

This study was designed to investigate bone remodelling around the cup in cementless THA. Previous studies indicate an advantage of better sealing of the bone-prosthesis interface by HA/TCP coating of implants, inhibiting polyethylene-induced osteolysis. One hundred patients gave informed consent to participate in a controlled randomized study between porous coated Trilogy versus Trilogy Calcicoat (HA/TCP coated). The cup was inserted in press-fit fixation. The femoral component was a cementless porous coated titanium alloy stem (Bi-Metric), with a modular 28-mm CrCo head. The Harris Hip Score (HHS) and bone mineral density (BMD) determined by DEXA scanning were used to study the effect. Measurements revealed no difference between the two groups after 3 years either in the clinical outcome or in terms of periprosthetic bone density. Patients with a body mass index above normal regained more bone mineral than patients with normal weight. This finding supports the assumption that load is beneficial to bone remodelling.

Figures

Fig. 1

Inclusion diagram

Fig. 2

Modified Wilkinson regions of interest

Fig. 3

Bone mineral density changes in the different regions of interest. No significant differences between treatment groups

Fig. 4

Influence of body mass index on bone mineral changes. Similar differences in all regions, significant in ROI 3