Two Cases of External Auditory Canal Osteonecrosis in Patients on Antiresorptive Therapy for Osteoporosis

Bisphosphonates and denosumab have demonstrated overwhelmingly favorable skeletal benefit/risk profile in managing postmenopausal osteoporosis. External auditory canal osteonecrosis is a rare skeletal complication of antiresorptives previously described in 11 patients with bisphosphonate exposure and 1 bisphosphonate-naïve patient on denosumab. We present 2 patients who developed external auditory canal osteonecrosis while taking antiresorptives for postmenopausal osteoporosis; a 79-year-old asymptomatic bisphosphonate-naïve woman with 2-year exposure to denosumab, and a 64-year-old woman with otalgia after 5 years of risedronate and 5 years of denosumab treatment. Neither patient had previous exposure to glucocorticoids or local radiotherapy. Otoscopy performed by an ear/nose/throat (ENT) surgeon revealed exposed areas of bone in external auditory canal in both patients. Computed tomography of temporal bones found no evidence of bone erosion. Bone turnover markers were suppressed. Both patients ceased denosumab and were managed conservatively, with stable external auditory canal findings after 12 months. Although external auditory canal osteonecrosis is a rare skeletal complication of antiresorptive use, development of localizing symptoms in the ear should alert physicians to this rare clinical entity and prompt ENT surgical referral for early diagnosis and initiation of management.