Review Question - QID 212964

The patient has a Holstein-Lewis fracture, or fracture of the distal one-third of the humeral shaft associated with neuropraxia of the radial nerve. The profunda brachii artery runs with the radial nerve.

The profunda artery and radial nerve exit the triangular interval between the long head of the triceps and the humerus and travel in the spiral groove distally. The nerve crosses the spiral groove and pierces the intermuscular septa 7.5cm proximal to the elbow joint. In this region, the nerve is at risk of injury during humeral shaft fractures. A radial nerve palsy would present with an inability to extend the wrist, thumb, and fingers. The vast majority (80-90%) of radial nerve injuries in the setting of humeral shaft fractures recover with expectant management, and as such radial nerve injury is not an indication for operative management.

Rutgers and Ring reviewed 49 diaphyseal humerus fractures treated non-operatively. They reported that union was achieved in 44 (90%), while 4 of 14 (29%) proximal third fractures, 1 of 22 (4%) of the middle third, and no distal third fractures went onto non-union. They concluded that proximal-third long oblique fractures are at a higher risk for non-union when treated without surgery.

Westrick et al reviewed 296 patients with humeral shaft fractures, 69 of which were treated with a brace and 227 which received surgery. They found that non-operative management resulted in a higher non-union rate (23.2% vs 10.2%) despite higher energy mechanisms in the fixation cohort. the authors noted that no difference in time to union was noted and that nerve palsy was more common in the surgical group (39% vs 20%).

Nachef et al reviewed 373 patients with humeral shaft fractures, of which 43 had an associated radial nerve palsy. Of the 17 radial nerve palsies included at final follow-up, the authors noted that 13 were present preoperatively, and that 10 of these recovered and 3 did not by the mean final 26-month follow-up. Of the 3 patients who did not recover, upon surgical exploration 2 had gross damage and 1 had a nerve contusion and a history of spinal muscular atrophy. Of the 4 postoperative radial nerve palsies, 2 fully recovered and 2 partially. The authors noted that more fracture displacement and higher-grade open wounds were associated with radial nerve palsies.

Figure A is an AP radiograph demonstrating a displaced distal one-third humeral shaft fracture.

Incorrect Answers:
Answer 2: The posterior circumflex humeral artery runs with the axillary nerve in the quadrangular space.
Answer 3: The scapular circumflex artery runs in the triangular space, without a major nerve.
Answer 4: The brachial artery runs on the medial aspect of the arm in close proximity to the ulnar and median nerves.
Answer 5: The lateral thoracic artery stems from the axillary artery and follows the lower border of the pectoralis minor, supplying the serratus anterior muscle.