The nerves in our body convey information to the brain on the one hand (sensory nerves) and messages from the brain to activate the muscles on the other (motor nerves). In order to function this way they have to reach all parts of the body and penetrate anatomical structures such as joints, bones and muscles. Normally, there is enough space for the nerves to go through easily.
In cases of trauma, edema or any compression, the area through which a nerve passes may be restricted and may cause pain, hypersensitivity, paralysis or other malfunctions.
The painful burning sensation on the outside of the thigh may imply that one of the large aesthetic nerves of the lower extremities – the lateral femoral cutaneous nerve – is trapped and compressed. This pathological condition is known as the neuropathy of the lateral femoral cutaneous nerve or meralgia paresthetica.
- Pain on the exterior surface of the thigh, occasionally extending to the exterior surface of the knee
- Feeling of burning sensation and numbness in the affected area.
- Occasionally, pain in the groin that can sometimes spread to the entire buttock area.
- It is usually located only on one half of the body.
- Greater sensitivity to light touch than to constant pressure.
During physical examination, the Orthopedist may ask the patient about recent surgeries, hip injuries or activities that could irritate the nerve. In addition, he will examine the patient for any aesthetic differences between the affected and the healthy limb. To verify the findings, the physician applies pressure to the nerve to reproduce the sensation mentioned above. Finally, a detailed abdominal examination may be deemed necessary to rule out any concomitant problems.
Radiographs can help detect any abnormalities in the bones that exert pressure on the
nerve. Magnetic resonance imaging (MRI) or computed tomography (CT) may be recommended if there is a suspicion of a tumor as a nerve pressure source. Finally, in some cases a nerve conduction study of the lower extremities may be recommended.
Narrow clothing and weight gain are two common reasons for nerve pressure. Information is helpful if the patient uses heavy or tight belts and toolboxes at work or if he or she follows a weight loss program. Rarely, it can be caused by a car seat belt after an injury.
The methods of treatment vary depending on the reason of pressure. It may take some time for the symptoms to subside and in some cases numbness may persist. The goal of treatment is to remove the causes of compression. This may mean losing weight, stopping intense and aggravating activities or wearing wider clothing. Persistent and more severe symptoms may be alleviated by corticosteroid (cortisone) injections, which can relieve symptoms for a period of time. In very rare cases, surgery is necessary to release the nerve.