Bone mineral density changes after total knee arthroplasty: One-year follow-up

The study involved analysis of differences in bone mineral density (BMD) in the region of knee arthroplasty ill 106 female patients. BMD was assessed using dual-energy X-ray absorptiometry ill a follow-up time schedule: before surgery and 2 weeks postoperatively (baseline). 5, 12, 24, and 48 weeks after knee joint arthroplasty. Four assessment regions A. B. C, and D were determined in immediate proximity to the arthroplasty site. A year after surgery. a decrease in BMD was observed in all determined regions-(9.9%, 13.8%, 9.9%, and 7.6% respectively) in comparison with the baseline value. The most significant BMD decrease was observed in the period between 5 and 12. weeks alter the knee joint arthroplasty. In our opinion, the decrease in BMD ill the knee joint arthroplasty site is a result of the postoperative increased bone resorption and decreased patient motor activity.