Distal humerus nonunion: evaluation and management

Overview

This review by Vauclair, Goetti, Nguyen and Sanchez-Sotelo, published in EFORT Open Reviews in 2020, addresses nonunion after distal humerus fractures. Despite better implants, nonunion occurs in 8 to 25% of surgically treated fractures, which is more often than at other humerus sites. The article covers evaluation, the choice between internal fixation and elbow arthroplasty, outcomes and technical points.

Evaluation

Patients report pain, limited motion and instability, and may have ulnar neuropathy. Modifiable risk factors such as smoking, poor nutrition, metabolic disorders, immunosuppressant drugs and infection must be identified and improved. Records of earlier operations, the soft tissue envelope and the ulnar nerve are reviewed. A recent CT scan shows the nonunion pattern, remaining bone stock, previous hardware and any arthritis or articular malunion. The Mitsunaga classification is preferred over the AO/OTA scheme. Deep infection should be excluded with blood tests, aspiration and tissue samples at surgery.

Treatment choice

Non-operative care is reasonable for low-demand patients. Internal fixation is the treatment of choice for most patients with reasonable bone stock and preserved cartilage. Total elbow arthroplasty is an alternative for severe destruction of the articular cartilage or severe bone loss, especially in older women, but it is used cautiously in younger men and in patients with previous deep infection. Arthrodesis is a salvage option, and whole allograft replacement is not recommended.

Technique and outcomes

Fixation usually needs stable fixation with two parallel plates and long screws, release of elbow contracture, bone graft (often from the iliac crest) and care of the ulnar nerve, with an olecranon osteotomy as the usual exposure. Infected cases favour a two-stage approach. In nine studies of fixation (166 patients), union was reached in 96.9%, the complication rate was 23% and 73.9% of results were satisfactory. In five studies of arthroplasty (138 patients, mean age 65.6), 79% were satisfactory, but complications occurred in about 43% and reoperation was common. Both approaches therefore leave room for improvement.