Osteonecrosis of the jaw in older osteoporosis patients treated with intravenous bisphosphonates

BACKGROUND: Intravenous bisphosphonate therapy has been linked to osteonecrosis of the jaw among patients with cancer. Some patients with osteoporosis also receive intravenous bisphosphonates, although at lower total doses than those with cancer. OBJECTIVE: To examine the risk for jaw osteonecrosis among a population-based cohort of older adults receiving intravenous bisphosphonates for the treatment of osteoporosis. METHODS: Using a 5% national sample of Medicare beneficiaries, we identified 2296 patients treated with intravenous infusions of bisphosphonates for osteoporosis and other metabolic bone diseases between January 1, 2000, and December 31, 2007. We matched this cohort to 6865 bisphosphonate nonusers, at a 1:3 ratio, on age, race, sex, type of bone disease, and risk factors for osteonecrosis of the jaw. Patients were followed until December 31, 2007. The jaw toxicity outcomes included operations on the facial bones or jaw and diagnosis of inflammatory conditions of the jaw. RESULTS: The absolute risk at 3 years for any jaw toxicity was 0.70 events per 100 patients using bisphosphonates and 0.30 events per 100 patients not using such drugs (2-sided log rank test, p = 0.08). In multivariable survival analyses (Cox proportional hazards regression) adjusting for potential confounders, intravenous bisphosphonate use was not significantly associated with diagnoses or procedures suggestive of osteonecrosis of the jaw (p = 0.24). CONCLUSIONS: Patients with osteoporosis who are treated with intravenous bisphosphonates do not appear to have a statistically significant increase in the incidence of osteonecrosis of the jaw over 3 years compared with those who do not receive such treatment. Future studies will further contribute to our understanding of the bisphosphonate risk profile, thereby allowing patients and physicians to more rigorously assess the risk-benefit ratio of this treatment across different clinical scenarios.