Femoral neuropathy, or femoral nerve dysfunction, occurs when you can’t move or feel part of your leg because of damaged nerves, specifically the femoral nerve. This can happen from an injury, prolonged pressure on the nerve, or damage from disease. In most cases, this condition will go away without treatment. However, medications and physical therapy may be necessary if symptoms don’t improve.
The femoral nerve is one of the largest nerves in your leg. It’s located near the groin and controls the muscles that help straighten your leg and move your hips. It also provides feeling in the lower part of your leg and the front of your thigh. When this nerve is damaged, it affects your ability to walk and may cause problems with sensation in your leg and foot.
Damage to the femoral nerve can be the result of:
- a direct injury
- a tumor or other growth blocking or trapping part of your nerve
- prolonged pressure on the nerve
- a pelvic fracture
- radiation to the pelvis
- hemorrhage or bleeding into the space behind the abdomen, which is called the retroperitoneal space
- a catheter placed into the femoral artery, which is necessary for certain surgical procedures
Diabetes is a common cause of femoral neuropathy. Diabetes can cause widespread nerve damage due to fluctuations in blood sugar and blood pressure. Nerve damage that affects your legs, feet, toes, hands, and arms is known as peripheral neuropathy. Femoral neuropathy falls into this category.
According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), diabetes is the most common reason for peripheral neuropathy in people who have had diabetes for at least 25 years. Peripheral neuropathy that’s caused by diabetes frequently affects the femoral nerve.
This nerve condition can lead to difficulties moving around. Your leg or knee might feel weak, and you may be unable to put pressure on the affected leg.
You might also feel abnormal sensations in your legs. They include:
- numbness in any part of the leg
- tingling in any part of the leg
- dull aching pain in the genital region
- lower extremity muscle weakness
- difficulty extending the knee
- feeling like your leg or knee is going to give out (buckle) on you
Prolonged pressure placed on the femoral nerve can prevent blood from flowing in the affected area. The decreased blood flow can result in tissue damage.
If your nerve damage is the result of an injury, it may be possible that your femoral vein or artery is also damaged. This could cause dangerous internal bleeding. The femoral artery is a very large artery that lies close to the femoral nerve. Trauma often damages both at the same time. Injury to the artery or bleeding from the artery can cause compression on the nerve.
Additionally, because the femoral nerve provides sensation to a major portion of the leg, injuries can occur due to this loss of sensation. Having weak leg muscles can also make you more prone to falling. Falls are of particular concern in older adults because they can cause hip fractures, which are very serious injuries.
To diagnose femoral neuropathy and its cause, your doctor will perform a comprehensive physical exam and ask questions about recent injuries or surgeries, as well as questions about your medical history.
To look for weakness, they will test specific muscles that receive sensation from the femoral nerve. Your doctor will probably check your knee reflexes and ask about changes in feeling in the front part of the thigh and the middle part of the leg. The goal of the evaluation is to determine whether the weakness involves only the femoral nerve or if other nerves also contribute.
Additional testing might include:
Nerve conduction checks the speed of electrical impulses in your nerves. An abnormal response, such as a slow time for electrical signals to travel through your nerves, usually indicates damage to the nerve in question.
Electromyography (EMG) should be performed after the nerve conduction test to see how well your muscles and nerves are working. This test records the electrical activity present in your muscles when the nerves that lead to them are active. The EMG will determine whether the muscle responds appropriately to stimulation. Certain medical conditions cause muscles to fire on their own, which is an abnormality that an EMG can reveal. Because nerves stimulate and control your muscles, the test can identify problems with both muscles and nerves.
MRI and CT Scans
An MRI scan can look for tumors, growths, or any other masses in the area of the femoral nerve, which could cause compression on the nerve. MRI scans use radio waves and magnets to produce a detailed image of the part of your body that is being scanned.
A CT scan, using cross-sectional x-rays, can also look for vascular or bone growths.
The first step in treating femoral neuropathy is dealing with the underlying condition or cause. If compression on the nerve is the cause, the goal will be to relieve the compression. Occasionally in mild injuries, such as mild compression or a stretch injury, the problem may resolve spontaneously. For diabetics, bringing blood sugar levels back to normal may alleviate nerve dysfunction. If your nerve doesn’t improve on its own, you’ll need treatment. This usually involves medications and physical therapy.
You might have corticosteroid injections in your leg to reduce inflammation and get rid of any swelling that occurs. Pain medications can help relieve any pain and discomfort.
Physical therapy can help build up the strength in your leg muscles again. A physical therapist will teach you exercises to strengthen and stretch your muscles. Undergoing physical therapy helps to reduce pain and regain mobility.
You might need to use an orthopedic device, such as a brace, to assist you with walking. Usually, a knee brace is helpful in preventing knee buckling.
Depending on how severe the nerve damage is and how much trouble you’re having moving around, you might also need occupational therapy. This type of therapy helps you learn to do regular tasks like bathing and other self-care activities. These are called “activities of daily living.” Your doctor might also recommend vocational counseling if your condition forces you to find another line of work.
Your doctor might recommend surgery if you have a growth blocking your femoral nerve. Removing the growth will relieve the pressure on your nerve.
You might be able to heal fully after you treat the underlying condition. If the treatment isn’t successful or if the femoral nerve damage is severe, you might permanently lose feeling in that part of your leg or the ability to move it.
You can lower your risk of femoral neuropathy caused by diabetes by keeping your blood sugar levels under control. This helps protect your nerves from damage caused by this disease. Preventive measures would be directed at each cause. Talk to your doctor for advice about what preventive measures would be the best for you.