Ulnar nerve palsy at the elbow after surgical treatment for fractures of the olecranon.

Despite close proximity of the fracture site to the nerve, ulnar nerve palsy after surgery for fracture of the olecranon is uncommon. We examined 18 cases of fracture of the olecranon treated surgically retrospectively to see if there were any characteristics common to 4 cases of ulnar nerve palsy. Three cases of palsy with a comminuted fracture had fair or poor reduction as revealed by both the lateral and anteroposterior radiographs taken at the time of surgery. The other case, with little displacement of the fragment, had osteoarthritic changes at the medial side of the elbow. The mechanism of development of ulnar nerve palsy is considered to be multifactorial. However, it should be noted that evaluation of reduction of the fracture, not only on a lateral radiograph but also on an anteroposterior radiograph at the time of surgery, is important to prevent the ulnar nerve from being jeopardized.