The propensity of common peroneal nerve in thigh-level injuries.

BACKGROUND

Sciatic nerve lesions comprise the largest subset of lower extremity nerve injuries. Military gunshot injury reports in civilians are not as predominant as wartime experience. Most sciatic nerve injuries result in deficits to the peroneal component. This study aims to report experience with civilian sciatic nerve injuries and to suggest the mechanism behind the peculiarity of the common peroneal component in thigh-level injuries.

METHODS

A retrospective study was conducted on 1,463 civilian patients with military gunshot sciatic nerve injury diagnosed and evaluated by neurophysiologic studies during a period of 3 years.

RESULTS

Most of the patients (95.4%) presented with thigh-level injury in which 95% suffered complete but isolated common peroneal territory palsy. The rest of the patients had either solitary complete tibial division palsy or complete tibial and common peroneal deficits.

CONCLUSIONS

The propensity of the common peroneal nerve in thigh-level injuries inflicted by military-type weapons in civilians is consistent with wartime injury reports. Because of its special anatomic situation, entrapment of the common peroneal nerve whether distally or proximally may render its axons more prone to mechanical damage. Moreover, the smaller contribution of the common peroneal component to the main nerve may result in its damage more readily than the tibial component whose larger contribution may spare some of its fibers. Finally, the components of the sciatic nerve diverge at a variable distance from the knee. Thus, distal thigh injuries may involve the diverging common peroneal nerve where it has a superficial position and is more prone to injury.