Why do I have weakness climbing stairs? Femoral Neuropathy could be the answer
Anatomy: The Femoral Nerve runs down the front of the thigh. It supplies sensation to the skin of the front and inner thigh. As the nerve goes into the lower leg, it changes name to the Saphenous Nerve which supplies the inner aspect of the calf stopping at the inner ankle bone. The Femoral Nerve comes from the area of the spine known as Lumbar 2, 3, and 4 spinal segments. As it leaves the spine and goes downward toward the thigh, it passes through the psoas muscle which is the strong strap muscle that runs nearly vertically on each side of the spine. It continues downwards and under a strong strap called the Inguinal Ligament which runs roughly in line with the groin fold. Apart from the skin sensations mentioned above, the Femoral Nerve also supplies sensation and the ability to move to Quadriceps muscles on the front of the thigh and several muscles of the groin area. See the adjacent diagram.
Femoral Nerve Pain Causes
There can be several causes of injury, including direct trauma such as a blow to the lower abdomen, the groin or the front of the thigh. Diabetic muscle wasting is the most common cause of Femoral neuropathy. Also, the nerve can become entrapped as it leaves the spine or (more commonly) as it runs below the inguinal ligament at the site of the groin fold. At this point, the Femoral Nerve is in closely surrounded by the head of the femur (thigh bone), several muscle tendons and the soft tissue around the hip joint. It is vulnerable to compression from these structures. This can occur if the leg is forced into a ‘frog’ position for an extended period, from pressure from the baby during pregnancy, due to a traumatic blow or due to a build up of pressure from a tumour or significant intra-pelvic bleed. On occasion, the ‘bone cement’ used in hip replacement has been able to generate enough heat when setting to cause Femoral Nerve damage.
Femoral Neuropathy Symptoms
The symptoms of a femoral compression/neuropathy can include pain in the groin fold area that is somewhat alleviated by moving the leg half way to a cross-legged position. There may be odd skin sensations on the front of the thigh and the front / inner shin area. Sufferers will usually complain of knees buckling from weakness, pain around the knee cap and weakness walking upstairs. Often the feet will have to meet on a stair, rather than taking each in turn. On examination, hip flexion (lifting the thigh up) and knee extension (straightening from bent) are usually weak compared to the unaffected side. The Patella Tendon reflex may be impaired. Pain may be worsened by hip extension (moving your foot behind you while keeping the pelvis straight).
A neurologist can find definite evidence of a problem using a nerve conduction test. Treatment is entirely dependant on the cause of the femoral nerve pain.
How Serious is Femoral Nerve Compression?
If the damage to your femoral nerve results from an injury, the femoral artery and vein could also have been damaged and result in internal bleeding. The femoral artery is large and so this can be very dangerous and may itself cause compression of the femoral nerve.
The femoral nerve gives sensation to most of the leg and a loss of sensation can lead to injuries such as those caused by falling due to weak leg muscles. Prolonged pressure on the nerve can also cause reduced blood flow and tissue damage.
How is Femoral Nerve Damage Diagnosed?
A full physical examination and detailed questions about the patient’s medical history and the level of sensations experienced are normally necessary to achieve a diagnosis. These will include the examination of specific muscles that the femoral nerve controls and will also determine if other nerves are affected. Obvious signs are femoral nerve pain, weakness in the leg and unusual sensations.
- a knee reflex check
- MRI or CT scans that provide detailed images to look for any growth that can cause the compression
- nerve conduction velocity checks to determine if electrical signals are travelling slower than normal through the nerve due to damage
- electromyography to see if the nerves and muscles are working correctly and if the latter respond to stimulation
- neuromuscular ultrasound, a relatively new method that diagnoses and guides treatment for medical conditions affecting nerves and muscles by identifying abnormalities in the shape of the nerve.
How is Femoral Neuropathy Treated?
Underlying conditions or other causes of the compression are generally treated first. This may involve reducing blood sugar levels where diabetes is a factor or relieving pressure on the nerve. Problems caused by mild injuries may resolve themselves but possible treatments include:
- medication to relieve the pain
- a cortisone injection to reduce swelling
- physical therapy to stretch and strengthen muscles, increase mobility and reduce pain
- fitting an orthopaedic device, such as a brace, to prevent knee buckling and help with walking
- occupational therapy that will help with daily activities
- vocational therapy where a change of career is required due to the condition
- surgery to remove a growth that is causing pressure on the nerve
- lifestyle changes, such as not wearing tight clothing, avoiding activities that put pressure on the femoral nerve and losing weight if this contributes to nerve damage.
What are the Long-term Effects?
Successful femoral nerve compression treatment of the underlying condition may resolve the problem entirely. If damage to the nerve is too severe or the treatment doesn’t work, however, a permanent loss of feeling or mobility in the leg may be experienced. This may result in a degree of permanent disability.
Leg injuries may go unnoticed due to a loss of sensation and may get worse as a result. A change of occupation and the regular wearing of a brace may also be necessary.
How can Femoral Nerve Pain be Prevented?
An active lifestyle is recommended because this will ensure leg muscles are strong and will improve mobility. Nerve damage due to diabetes can also be prevented by keeping blood sugar levels low, which will minimise the risk of contracting the condition. If obesity is a factor in the onset of diabetes or the nerve compression itself, losing weight will obviously help.
Nerve damage can result from a number of different causes and preventative measures will be directed at each one. It is, therefore, generally best to consult our podiatrists in Brisbane to determine the measures that are most suitable for your femoral nerve pain.