Review Question - QID 214115

This patient sustained a humeral shaft fracture with an associated radial nerve palsy. Recovery of the radial nerve is expected and typically occurs in a predictable order with the brachioradialis recovering first and the extensor indicis proprius (EIP) recovering last. Function typically recovers in more proximal muscles first and more detail muscles later on.

Humeral shaft fractures have a bimodal distribution occurring in young patients after high-energy trauma and in elderly osteoporotic patients after low-energy trauma. The vast majority of humeral shaft fractures can be successfully managed conservatively. The acceptable criteria for conservative management of humeral shaft fractures include <20 degrees of AP angulation, <30 degrees of varus/valgus angulation, and <3cm of shortening. Most commonly, these fractures are immobilized initially with use of a coaptation splint. After allowing for improvement in swelling, these patients are transitioned to a functional brace 1-2 weeks later. Associated radial neuropraxia is often observed and recovers in a predictable order, with the EIP most often recovering last.

Updegrove et al. reviewed humeral shaft fracture management. They note that nonoperative management remains the standard of care. They found that fracture pattern, location, and identifiable patient risk factors may predict poor outcome with nonoperative management. They conclude that operative management may include open reduction and internal fixation through a variety of exposures, intramedullary nail fixation, external fixation, and shoulder arthroplasty in patients who are believed to do poorly with nonoperative management.

Carroll et al. review humeral shaft fractures management. They report that nonsurgical management of humeral shaft fractures with functional bracing gained popularity in the 1970s and remains the standard of care for these fractures. They also note that surgical management is indicated in polytraumatic injuries, open fractures, vascular injury, ipsilateral articular fractures, floating elbow injuries, and fractures that fail nonsurgical management. They also report on the relatively high incidence of radial nerve injury which has been associated with surgical management of humeral shaft fractures.

Figures A is the AP radiograph demonstrating a comminuted humeral shaft fracture. Figure B is the brachioradialis muscle. Figure C is the ECRB muscle. Figure D is the ECU muscle. Figure E is the extensor digitorum muscle. Figure F is the EIP muscle.

Incorrect Answers:
Answer 1: The brachioradialis is one of the first muscles expected to recover from a radial nerve palsy and will result is wrist extension with radial deviation.
Answers 2: The ECRB is also expected to have early functional recovery following a radial nerve palsy.
Answer 3: The ECU is innervated by the posterior interosseous nerve.
Answer 4: The extensor digitorum would be expected to recover earlier than the EIP following a radial neuropraxia.