Review Question - QID 220019

This patient has sustained a comminuted, intraarticular distal humerus fracture. She has persistent ulnar nerve symptoms after open reduction and internal fixation (ORIF) with in-situ cubital tunnel release. In the absence of excessive stretch or nerve-implant contact, transposition is not indicated, and the patient is best treated with observation alone (Answer 1).

Intraarticular distal humerus fractures are severe elbow injuries that are commonly associated with ulnar nerve injury, most commonly neurapraxia. These fractures are best treated with ORIF with either parallel or orthogonal bicolumnar plating. During dissection, the ulnar nerve should be exposed and protected. Patients with preoperative cubital tunnel syndrome should undergo cubital tunnel release. Debate persists on the utility of transposition, but the current literature suggests no difference in outcomes, with some studies suggesting increased symptoms in patients who undergo transposition. Transposition should be reserved for ulnar nerves on excessive stretch or may be lying in contact with implants after internal fixation.

O'Driscoll presents 8 technical principles that should be abided by when performing internal fixation of complete articular distal humerus fractures. Rigid dual plating should be performed, with as many screws as possible in the distal segment and all screws passing through the plate, leading to interdigitation and a highly stable construct capable of tolerating the stress of elbow range of motion during the healing phase.

Chen et al. present a multicenter retrospective series of 137 patients undergoing distal humerus ORIF with and without ulnar nerve transposition. They found a higher rate (33%) of ulnar neuritis in the transposition group than in the in-situ group (9%). They recommend avoiding ulnar nerve transposition when able.

Dehghan et al. performed a multicenter randomized controlled trial across 8 Canadian centers, investigating 58 patients undergoing distal humerus ORIF with either in-situ cubital tunnel release or release with anterior subcutaneous ulnar nerve transposition. They found a high incidence of overall nerve conduction abnormalities on EMG performed at 6 weeks, but ultimately no difference in neurologic outcomes between the groups. The majority of patients had improvement at final followup. They suggest that the decision on ulnar nerve transposition be left to the discretion of the operating surgeon.

Figure A is an AP elbow radiograph demonstrating a complete articular comminuted distal humerus fracture. Figure B is a fluoroscopic AP image demonstrating interval reduction and internal fixation with bicolumnar orthogonal plating.

Incorrect Answers:
Answer 2: EMG is not indicated in the acute postoperative period and would be of limited utility.
Answer 3, 4: Given that the nerve was adequately decompressed and left without excessive stretch or implant irritation, there is no indication for revision cubital tunnel release at this point.
Answer 5: There is no indication for Guyon's canal release.