Abstract
Bone mineral density (BMD) around the stem of OMNIFLEX® was measured 2-4 times (mean 2.9 times) during 15 months after surgery with Lunar DPX in 16 hips of 14 patients (OA, RA or ANF). Percent BMD changes per month were calculated in 7 regions according to Gruen's classification.
Bone mineral density reduced most markedly during the first 6 months after surgery in every region, and than stabilized or increased in later periods. During the first 6 months, region 7 (Calcar region) showed the most marked BMD reduction when compared to other regions. BMD was stabilized or increased in at least 50% of patients the earliest (3-9 months) in region 1 and 2, 6-12 months in region 3, 9-15 months in region 4 and 7, while BMD kept reducing in region 5 and 6 throughout all postoperative periods. This finding suggests that BMD stabilized or increased earlier on the lateral rather than medial side of the stem.