Review Question - QID 219610

This 26-year-old female sustained a humeral shaft fracture secondary to a ballistic injury with an associated radial nerve palsy. Early (less than two weeks) radial nerve exploration provides no additional benefits over late (greater than two weeks) exploration (Answer 4).

Humeral shaft fractures are commonly encountered traumatic injuries, encapsulating 3 to 5% of all fractures, with a predilection for younger patients with higher energy mechanisms and elderly patients with low energy injuries. These injuries have a high rate of associated radial nerve palsies, with the distal one-third fracture having the highest incidence (22%; "holstein-lewis fractures"). Fortunately, the vast majority (80-90%) of radial nerve palsies recover without intervention, and as such, a radial nerve injury in the setting of closed fracture often begets a Sarmiento brace, similar to the vast majority of humeral shaft fractures. In the setting of open humeral shaft fractures with radial nerve palsies, however, the current recommendation is to explore the radial nerve, given the high rates of neurotmetic injuries secondary to complete or partial transections necessitating coaptation.

Foster et al. report on a case series of fourteen patients who sustained open humeral shaft fractures with associated radial nerve palsies. The authors noted 64% of patients exhibited a lacerated or interposed radial nerve within the fracture fragments. There were similar rates of injury seen between Gustilo-Anderson grades. The authors recommend rigid, internal fixation of the fracture with epineural radial nerve coaptation to facilitate the best chance for return to function.

Shao et al. performed a systematic review of 35 papers examining the management of humeral shaft fractures with associated radial nerve palsies. The authors noted an overall 11.8% incidence, with the junctional middle and distal third having the highest prevalence (20 to 23.6%). Of those undergoing exploration, the majority demonstrated an intact or only contused nerve (46.3%), while 23.4% had a transected nerve. Ultimately, the authors noted an 88.1% overall nerve recovery rate. There was no difference in outcomes between early and delayed exploration.

Li et al. performed a systematic review of 30 studies (n=2,952) examining humeral shaft fractures with concomitant radial nerve palsies and the most appropriate treatment. The authors noted no difference in functional recovery and emphasized the lack of consensus regarding the ideal treatment strategy. Despite this, the authors propose an integrated treatment strategy and recommend early exploration of open fractures secondary to high rates of radial nerve transection (45.8%). In high-energy fractures, the authors recommend evaluation of the nerve site via ultrasound and treatment based on the findings of the study. In low-energy fractures, observation can be performed.

Figures A & B demonstrate orthogonal plain films of a comminuted left midshaft fracture in varus angulation. Figures C & D demonstrate postoperative imaging with a 3.5 mm humeral plate in bridge mode.

Incorrect Answers:
Answers 1, 2, 3, and 5: early exploration has not been shown to impact the course of radial nerve recovery.