Bone mineral density as a marker of hip implant longevity: a prospective assessment of a cementless stem with dual-energy X-ray absorptiometry at twenty years

Bone remodeling around the femoral component after total hip arthroplasty (THA) is considered to be an important factor in long-term stability and seems to be strictly related to the stem design, coating, and fixation. Stress shielding, micro-movement, and high intra-articular fluid pressure might activate macrophages and osteoclasts, causing progressive bone density decreases. Here we analyze the bone mineral density (BMD) around a cementless femoral stem during a 20-year period to better understand the adaptive bone changes around such implants during long-term follow-up.