Postoperative femoral neuropathy.

Postoperative femoral neuropathy is more common than it is generally appreciated. It can occur by a number of different mechanisms after a wide variety of operations as a result of either direct or indirect injury. Most instances occur after abdominopelvic operations and are associated with the placement of self-retaining retractors. A large body of evidence suggests that, in these patients, nerve compression by the lateral blades of the retractor is the cause. There is, however, evidence that the intrapelvic portion of the nerve is particularly susceptible to ischemia. Usually, there is a mild sensorimotor disturbance and the diagnosis is easily made by accurate physical examination during the early postoperative period. A diminished or absent knee jerk is the most reliable clinical sign. Recovery is the rule; it occurs usually from a few weeks to months. During this time, physiotherapy may be beneficial. Occasionally the lesion may be severe or prolonged, or both. In these instances, EMG studies are justified, not only to allay the fears of patients and physicians, but to evaluate the progress of the lesion over time. With the exception of certain unusual instances, this potentially debilitating postoperative complication can be avoided by careful placement of self-retaining retractors.