Zoledronic acid for osteoporosis after distal radius fracture surgery: Prospective longitudinal study.

Background: Distal radius fractures (DRFs) are the most frequent first-ever osteoporotic fragility fractures. However, most patients are treated only for fractures and not for osteoporosis. Therefore, we investigated early osteoporosis intervention using zoledronic acid. Methods: This prospective study enrolled 30 patients aged 50 years or older who had no history of fragility fractures or osteoporosis treatment and who underwent surgical treatment for DRFs. Patients whose lumbar spine or femur bone mineral density (BMD) values were less than 80% of the young adult mean (YAM) were treated with a 5-mg intravenous infusion of zoledronic acid. Lumbar spine and femur YAM BMD values, TRACP-5b and PINP were statistically evaluated using the paired t-test. The relationship between adverse effects, age, body mass index (BMI), and creatinine clearance (CCr) was statistically examined using Mann-Whitney's U test. The incidence of the bone fusion and secondary fractures within the 60-months postoperative period were assessed. Results: The mean lumbar spine and femur YAM BMD values before treatment were 76.1 ± 13.1% and 70.7 ± 8.5%. This indicates osteopenia in both locations. These values differed significantly between the pre-treatment period and each subsequent period. Five patients with a target YAM BMD value over 80% within 60 months after treatment were observed. The TRACP-5b and PINP values differed significantly between the pre-treatment period and each subsequent period. Adverse drug reactions were observed in 12 patients (40%). Age, BMI, and CCr did not show statistically significant differences in the occurrence of adverse effects. Bone fusion was confirmed at a mean of 3.6 months postoperatively. Secondary fractures were observed in 3 patients within 60 months after treatment. Conclusion: DRFs occur at a younger age than other fragility fractures, and it is important to intervene aggressively with osteoporosis treatment to prevent secondary fractures. Level of evidence: Level V.