(0905) Antiresorptive Therapy-Induced Osteonecrosis of the External Auditory Canal: A Systematic Review

Introduction: Osteonecrosis of the external auditory canal (EAC) is an underrecognized complication of antiresorptive medications, such as bisphosphonates and denosumab, that are widely used for osteoporosis and cancer treatment. This systematic review aimed to characterize the range of documented clinical presentations, management strategies, and outcomes for this morbid condition.

Methods: Systematic review of observational studies (case series and reports) was performed following PRISMA guidelines. Computerized searches of PubMed, Scopus, and Web of Science databases through July 2023 and manual searches of retrieved article citations were completed. Two independent reviewers screened each abstract, extracted pre-defined data, and assessed risk-of-bias.

Results: A total of 14 studies were identified including 27 cases of EAC osteonecrosis (79% women, ages 51-89 years) following use of bisphosphonates (67%), denosumab (15%), or both (19%). Duration of drug use prior to osteonecrosis diagnosis ranged from 3 months to 15 years. The most common presenting symptoms were otalgia and purulent otorrhea. Lesions most often comprised ulceration/ necrosis of the EAC floor (41%), and 50% were bilateral. Antiresorptive drugs were discontinued in 86% of cases. Conservative management (debridement, topical/parental antibiotics) achieved symptom resolution and/or re-epithelialization in 61% of cases over 1 to 3 years while 39% underwent surgical debridement with or without grafting.

Conclusions: Clinicians should consider antiresorptive drug-associated osteonecrosis in the differential diagnosis of EAC ulceration and bony necrosis. When medically feasible, drug discontinuation may be necessary to prevent progression. While additional investigation is needed to determine the optimal approach, many cases respond to conservative management.