Prospective comparison of differences in bone mineral density adjacent to two biomechanically different types of cementless femoral stemsZerahn, B., Lausten, G.S. & Kanstrup, IL.
We compared the differences in bone mineral density (BMD) adjacent to two biomechanically different cementless femoral stems (Spotorno and Evolution-K). Measurements were performed within the first week after surgery and 3, 6, 12, and 24 months postoperatively in a prospective study of 31 patients with 37 total hip arthroplasties. A modified Harris hip score and a visual analogue score for patient satisfaction was used to evaluate the clinical outcome. For both stems, dual X-ray absorptiometry measurements revealed a decrease in BMD in Gruen zone 7. Patients with a Spotorno stem also had a significant decrease in BMD in zones 1 and 2. In patients with an Evolution-K stem, there was a positive correlation between the clinical outcome and BMD in Gruen zones 1 and 4. Our data suggest that periprosthetic bone loss is equal to if not less pronounced adjacent to the Evolution-K stem as compared to the Spotorno stem.