Symptoms of femoral nerve dysfunction include tingling, pain, numbness, burning and decreased sensation in the knee, thigh or leg, reports MedlinePlus. Additional symptoms are weakness in the leg and difficulty going up or down stairs, including a feeling of the knee trying to give way.
In order to determine if the femoral nerve is damaged, a doctor examines the muscles and nerves in the leg, explains MedlinePlus. The doctor looks for sensation changes on the front of the thigh or foreleg, abnormal knee reflexes, weakness when bending at the hip or straightening the knee, and abnormally small quadriceps muscles. Potential tests include an MRI to check for tumors or abnormal masses, an electromyograph and nerve conduction tests. Depending on a patient's symptoms and medical history, additional tests might include X-rays and blood tests.
Femoral nerve dysfunction is sometimes caused by compression due to nearby abnormal blood vessels or tumors, a direct injury or prolonged pressure that leads to decreased blood flow, notes MedlinePlus. Other causes include the insertion of a catheter into the femoral artery, internal bleeding in the abdomen, a broken pelvis and diabetes. Lying in a supine position with flexed legs and thighs during diagnostic procedures or surgery is a common risk factor. Major weight gain or loss, heavy or constricting waist belts and widespread nerve damage from other causes are also risk factors that may result in femoral nerve dysfunction.