Osteonecrosis of the Temporal Bone Secondary to Bisphosphonates: A Potentially Life‐Threatening Complication

Abstract

Objectives: (1) Describe how osteonecrosis of the temporal bone can present as a potentially life-threatening side effect of bisphosphonates. (2) Recognize that bisphosphonates are commonly prescribed and as such many of our patients could potentially experience these complications. (3) Apply this knowledge to achieve a timely diagnosis and to ensure patients are counseled regarding the risk of temporal bone osteonecrosis. Methods: Case study of 2 patients presenting to our clinic in Lanarkshire, Scotland, from 2012-2013: Patient A: A 53-year- old female with cholesteatoma was also receiving intravenous bisphosphonate therapy for osteoporosis. Patient B: A 57-year- old female on bisphosphonates presented with a left-sided facial palsy. Results: Patient A: During mastoidectomy the whole of the tegmen was noted to be brittle. A large piece of tegmen was found detached from the surrounding bone but was not affected by cholesteatoma. The tegmen defect was repaired and the patient is being followed up. Patient B had examination findings in keeping with otitis externa. A computed tomography scan demonstrated bone erosion involving the descending facial nerve. Comorbidities have prevented surgical management and despite discontinuing the bisphosphonate. The facial palsy has not resolved. Conclusions: Bisphosphonates can cause osteonecrosis of the temporal bone, including lower doses used to treat osteoporosis, especially in presence of localized infections. The otolaryngologist should be aware that complications such as tegmen erosion and facial palsy may occur. Patients with known infectious ear conditions considering treatment with bisphosphonates for osteoporosis should be counseled regarding the risk of osteonecrosis of the temporal bone.