Anterior interosseous nerve palsy as a complication of proximal humerus fracture.

Anterior interosseous nerve palsy subsequent to proximal humerus fracture is rare compared with an axillary nerve injury. This article presents a case of anterior interosseous nerve palsy secondary to such a fracture in an 87-year-old woman after a simple fall onto her outstretched hand. The patient had no sensory involvement but was unable to form an O with her thumb and index finger. She had a positive pointing index test on attempting to clasp her hand. The fracture and nerve palsy were treated conservatively. At 3-month follow-up, the patient had partial recovery; therefore, electromyography was not performed. By 6 months, she had complete recovery of anterior interosseous nerve palsy. This case highlights the possibility of sustaining anterior interosseous nerve palsy with proximal humerus fracture with a classical clinical presentation. Because most nerve lesions after proximal humerus fracture are neurapraxia, symptoms usually resolve either partially or completely after a few months. It is recommended that cases with proximal humerus fracture be evaluated carefully for median nerve and axillary nerve injury. In addition, it is recommended to perform electromyography if no signs of recovery are evident at 3-month follow-up.