The peroneal nerve is in the lower leg. It supplies sensation and movement to the knee joint, leg, foot and toes. The nerve divides into two branches and supplies muscles of the lateral and anterior leg compartments.
The peroneal nerve branches off the sciatic nerve and runs from behind the knee, passing down the back of the fibula. Inside the neck of the fibula, the peroneal nerve splits into two parts. These two parts are the superficial peroneal nerve and the deep peroneal nerve.
The superficial peroneal nerve is just under the skin’s surface and is therefore more prone to injury than the deep peroneal nerve. This nerve is responsible for skin sensation in the top of the feet and the calf area of the leg. When a nerve injury takes place, this leads to skin tingling or numbness.
The deep peroneal nerve controls the ankle and big toe on each foot. The deep peroneal nerve also affects sensation between the big toe and second toe. When the deep peroneal nerve becomes injured it can lead to foot and ankle problems.
When damage occurs to the peroneal nerve, the myelin sheath that covers the axon of the nerve can also be affected. Myelin is a substance that surrounds some of the nerves in the body. If the axon is also damaged, the symptoms associated with peroneal nerve damage can become worse.
Peroneal nerve damage may lead to a condition called peroneal nerve dysfunction. The symptoms of this can include:
- Loss of sensation
- Foot drop
- Weakness in the ankles
- Toe dragging
- Loss of muscle mass
- Walking difficulties
What Causes Peroneal Nerve Dysfunction?
Various circumstances can cause peroneal nerve dysfunction. These include leg or foot injuries, or even crossing the legs when sitting for too long. A poor sleeping position, tight leg casts or even wearing high boots can all create problems with the peroneal nerve. Nerves can also become damaged during some surgical procedures and when playing sports.
Any kind of knee injury can impair the peroneal nerve and surrounding muscles. Injuries such as breaks, fractures, sprains and dislocation can all cause damage. A blunt trauma to the knee can also injure the peroneal nerve.
Pressure on the knee is another way that the peroneal nerve can become injured. Poor posture when sleeping can damage the nerve and people who are bedridden are also susceptible to this condition.
Activities that put strain on the knee, such as: soccer, basketball, ice hockey or skiing, can damage the peroneal nerve. The knee acts as a shock absorber and it can normally take heavy impacts. However, playing active sports will put excess strain and pressure on the knee, which can affect the peroneal nerve.
Many professional sportsmen suffer nerve damage, either during their career or even after giving up the sport. Medical studies have concluded that the nerve injuries were due to playing stretching or contusion.
Knee or Leg Surgery
Any type of surgery on the knee or leg can damage the peroneal nerve. A surgeon could accidentally sever a nerve, or it can become bruised during the procedure. If injections are used, the peroneal nerve can suffer needle trauma which and possible nerve damage.
Varicose Vein Surgery
Varicose veins are swollen or enlarged veins, usually found on the legs. When the veins become painful, they are surgically removed to relieve pain and discomfort. The peroneal nerve can be damaged during varicose vein surgery.
Tumors in the lower leg and foot can damage the peroneal nerve. This could be due to pressure or the tumor becoming attached to the nerve. The pressure can cause entrapment of the nerve which will affect the way it operates. The nerve may also incur damage during surgery to remove a tumor.
Wearing Knee High Boots
People that regularly wear knee high boots risk damaging the peroneal nerve, particularly if they are tight. Boots that fit around the front and rear of the knee can put unnecessary pressure on the joint. Knee high boots also change the way some people walk, which puts strain on the knees, legs and feet.
Sitting with Legs Crossed
People that sit with crossed legs for any length of time are at risk of damaging the peroneal nerve. The damage can lead to foot drop and other symptoms which may affect mobility and quality of life. The damage caused by leg crossing also leads to tingling, burning and numbness in the foot.
A fracture of the fibula (lower leg bone) is another way that the peroneal nerve can become damaged. The nerve crosses the fibular neck and is prone to injury when the bone fractures. The fractured fibula will need to be stabilized with a cast until it heals, which can also cause problems.
If the cast is too tight on the lower leg, the peroneal nerve can sustain further damage. A tight cast will restrict blood flow and the nerve could become compressed. This will result in loss of sensation and the nerve will need to be untrapped to relieve the symptoms.
People who suffer from anorexia nervosa are susceptible to peroneal nerve damage due to malnutrition. Healthy nerves need a supply of vitamins and minerals from various types of food. There is medical evidence that anorectic patients have suffered peroneal nerve damage due to malnutrition.
Charcot-Marie-Tooth disease is an inherited disorder that causes nerve damage. The disease is incurable and people who suffer from it are at risk of peroneal nerve damage. The disease typically affects the arms, legs and feet; it also weakens the muscles.
How is an Injured Peroneal Nerve Diagnosed?
A doctor will carry out an examination and speak to the patient about their symptoms. The doctor can check the way the patient walks and examine their gait. The doctor will also examine the muscles to observe the ankle, foot and toe movement.
Doctors can also do various other tests, such as an electromyography, which checks electrical activity in the muscles. Nerve conduction tests can take place to check that the nerves are sending signals correctly. MRI and ultrasound scans are other tests that may also be used to diagnose problems with the peroneal nerve.
When the doctor has assessed the patient and diagnosed the root cause of the problem, a suitable treatment will be selected.
What Treatments Are Used for an Injured Peroneal Nerve?
Various treatments are available that can restore mobility and quality of life. Anti-inflammatory drugs can help minor problems; corticosteroids are also administered to patients to help reduce swelling. In addition, steroids can be used to inhibit protein production and reduce inflammation in the affected area. If these non-invasive measures do not improve the symptoms, then surgery is an option.
If the peroneal nerve injury has been caused by pressure, several surgical procedures that can help. Surgeons are able to relieve the pressure that is on the nerve, which will then restore mobility. If the peroneal nerve is compressed, a surgeon can free it to ease the symptoms.
If the nerve is severed, it can be stitched back together. The nerve will regenerate over the course of time. Healing time varies with each patient and age is also a factor. Grafting can also be used to repair broken nerves.
The nerve may also repair itself without medical intervention. However, the patient may still experience some pain and other symptoms while the nerve is healing. It is worth noting that a damaged nerve will never fully recover, and future damage is likely.
How Are the Symptoms of an
Injured Peroneal Nerve Managed?
Some patients will only need pain relief and anti-inflammatory drugs to deal with the symptoms of an injured peroneal nerve. If the pain is severe, a doctor may recommend a course of pain-killing injections. If the medication does not help, there are other options to consider.
Physiotherapy can be used to help patients manage the symptoms associated with an injured peroneal nerve. Physiotherapy may not help to repair a nerve, but it helps to maintain muscle strength. Having stronger muscles will aid mobility in patients with damaged nerves in the legs or feet.
If the patient is having trouble walking due to an injured peroneal nerve, there are orthopedic devices that can help. Custom footwear can be made; this helps to correct a poor gait and improve mobility. Splints and adjustable leg braces can also be fitted to patients if necessary, to aid mobility.
After reading the information about the peroneal nerve, it’s clear to see how important this nerve is for mobility and quality of life. It’s also interesting to note that some causes of peroneal nerve damage are preventable. Moreover, it’s good to know that several treatments are available to repair peroneal nerve injuries. If the damage is irreparable, there are many ways to help manage the symptoms.