Femoral mononeuropathy is caused by an injury to the femoral nerve as a result of trauma, ischemia, compression, or stretch injury. It can be associated with prolonged lithotomy position, retroperitoneal hemorrhage, penetrating injuries, pelvic masses, iliac aneurysms, or diabetes.

There is typically weakness of the quadriceps muscles leading to loss of strength in hip flexion and knee extension. This may cause difficulty walking or climbing stairs. Symptoms also include pain, medial thigh and calf numbness, and reduced or absent patellar reflex.

Prognosis depends on the extent and etiology of the injury, but patients can have full recovery over a period of months.