A case series title: femoral nerve injury with an episode of motor neuropathy caused by gynecological surgery: a case series.

Background: Although iatrogenic nerve injury is sometimes diagnosed after gynecological surgery, its incidence is underestimated because most cases are self-limiting and underreported. Herein, we report on six cases of femoral nerve injury after gynecological surgery with both sensory and motor neuropathy.

Methods: We retrospectively analyzed 785 patients with gynecological cancer requiring surgery, including lymph node dissection, between 2012 and 2016 at our center. The functional damage due to femoral nerve injury was postoperatively assessed and classified according to the Medical Research Council (MRC) scale by an orthopedist and a physiatrist. The eligibility criteria were grade 3 or less hip joint bending and muscular weakness due to nerve injury. Patients were excluded if they had been diagnosed with an isolated sensory disorder.

Results: We found six cases (0.76%) of femoral motor neuropathy resulting from gynecological surgery. All six patients underwent laparotomy using energy devices under general anesthesia with epidural anesthesia in the lithotomy position. Four of them recovered fully within 8 months from surgery with either physical therapy or no treatment, while the other two died within a year post-treatment; thus, recovery evaluation could not be accurately performed.

Conclusion: Postoperative femoral nerve injury can be diagnosed based on gait disturbances and difficulties climbing stairs. It is difficult to identify risk factors for femoral nerve injury as they may involve a combination of features, such as intraoperative compression with self-retaining retractors, the lithotomy position, and the use of energy devices. The surgeon should be familiar with the nature of energy devices, make every effort to understand the necessary anatomy, and make every effort to avoid femoral nerve injury. Iatrogenic femoral nerve injury caused by gynecological surgery should be further investigated regarding the patients' quality of life postoperatively.