Posterior interosseous Nerve Palsy after Corticosteroid Injection for Tennis Elbow

A 47-year-old healthy male was treated for his tennis elbow with a steroid injection elsewhere. In the affected forearm, he was surgical treated for a forearm fracture, thirty years previously. After the injection, he developed posterior interosseous nerve palsy. He was treated with neurolysis of the nerve from the radial tunnel and distal to the supinator, where it was found to be adherent to the healed fracture site. Most of the motor nerve function returned within two years. We believe this to be an example of a “double crush” phenomenon of the radial nerve. Injection of steroids to treat lateral epicondylitis is extremely common and previous injury or surgery to the extremity should be considered before its administration.