Pinched nerve in knee is very common among the elderly. The knee just like every part of the body has nerves. These nerves comes from the brain and spinal cord and their function is to send important messages to the body. They travel through narrow spaces and are found in vulnerable places but they have soft tissues that protect them.
When the nerves are pressed between tissues like the bones, tendons, the ligaments and other structures around them, it results to nerve compression which can cause pain. This is called pinched nerve, nerve compression or entrapment. The compression injures the nerves such that they cannot perform their functions. They can happen in the neck, shoulder, arm, elbow, wrist, hand, back , upper chest as well as knees.
This compression or pinched nerve is not only limited to the knees it can happen to every other nerve in the body. Pinched nerve in knees is the most common. Medical studies show that up to 25% of adults are affected by frequent knee pain ( Armour Physical Therapy, Michigan).
CAUSES OF PINCHED NERVE IN KNEE
The sciatic nerve also called the peroneal nerve is the only nerve going through the knee from the lower back and down to the lower leg, it is also at risk of being compressed or being pressured. The nerve lies at the bottom of the knee between the bone and the skin, this makes it vulnerable to be compressed by anything that puts pressure on the outside of the knee. This compression can be caused by traumatic injuries and other causes like:
Knee brace : Wearing a knee brace if it is tight or too rigid for a long period of time can compress the nerve in the knee.
Crossing your legs: Crossing your leg over the other can cause the knee under to be compressed thereby pressuring the nerve.
Squatting for long periods of time : This posture, when it is maintained for a long time can put pressure on the knee especially the sides.
Bone fracture: When the larger lower leg bone called the tibia or the smaller leg bone known as the fibula is fractured, the nerves around them can be entrapped.
Knee ligament injury : The ligament can be injured due to inflammation or bleeding, this can make the nerves around the knee to be pinched.
Knee-high boots: Knee-high boots are fashion clothings that lands right below the knee, a pinched nerve can develop after sometime.
Gynecologic or abdominal surgery : During surgery especially gynecologic and some abdominal surgeries, an equipment is used to keep the knees flexed and the legs rotated. This can compress the nerves around the knee.
Prolonged bed rest : While lying down, the legs can be flexed and the legs rotated outwards coupled with the bed, the nerves can be compressed.
Tumors or cysts : When tumours form around and in the nerves, these cysts can cause pressure on them.
Thigh-high compression stockings: These stockings are used to keep pressure on the legs but wearing them for a long time can cause compression on the nerves.
Complication of knee surgery : Surgeries like knee replacement or arthroscopic procedure sometimes require the nerves to be pinched.
Old age: As the body becomes older, the spine discs can loose water contents and get flat. This can make the bones in the spinal cord to move closer and the body starts growing bones, these bones can compress the nerves even in the knees.
Rheumatoid arthritis: Arthritis can happen to the knee and make the joints to be inflamed and this can pressure the nerves around the area.
Injury: Injury from sports or from movements can compress the nerves in the knee.
Obesity : When the body has excess weight, the nerve pathways can swell causing pressure on the nerves.
Pregnancy: Pregnancy can make the body to add more weight and this causes the nerves to be compressed.
SYMPTOMS OF PINCHED NERVE IN KNEE
The peroneal nerve is responsible for the sensation and movement of the lower leg and top of the foot. When the lining around this nerve is injured, it is painful. Also, when the nerve itself is injured, there is pain that is more severe. Other symptoms are:
- Numbness : The is absence of sensitivity and the inability or reduced ability to experience emotion in the knee, lower leg and top of the foot.
- Dorsiflexion: The leg can become weak and you are unable to lift your foot. This causes your foot to drag when you walk.
- Tingling or needles and pins feeling
- Burning sensation.
- Sensation that your foot has fallen asleep.
- Weak muscles.
HOW TO DIAGNOSE PINCHED NERVE IN KNEE
Most pinched nerve in knee can go away after some time while others can continue for a long time. If you continually feel the pain and other symptoms, you can see a doctor to know if it is caused by a pinched nerve in knee or another thing. To diagnose pinched nerve in knee, the doctor will carry out series of test like
(1) Nerve conduction test: This test is done to know how fast electrical impulse travels through your nerves. The nerves will be stimulated usually with electrode patches attached to your skin. This test is used to identify nerve damages.
(2) Knee X-ray: An x-ray machine is used for this test. The machine sends radiation through the knee and images are recorded on a computer screen on a special film. This image shows the lower leg bones, kneecap, bone above the knee, bones of the knee and tissues around these areas. Through this test, fractures and bone masses can be seen.
(3) Electromyogram (EMG): This procedure is used to test the health of the nerves and muscles. Electromyogram measures the electrical activity in response to the nerve’s stimulation of the muscle. ( John Hopkins Medicine ). The test is used to test abnormalities in the nerves.
(4) Knee MRI : This test is used to see the insides of the bones, ligaments, tendons, cartilage, muscles and the nerves around the knee. This will be used to detect the problems.
HOW TO RELIEVE PAIN OF PINCHED NERVE IN KNEE
Pinched nerve can be painful, the pain can be mild or severe depending on what caused the nerve to be compressed. To relieve the pain, you can use:
(1) Ice or heat : Placing an ice pack on the affected knee for at least 15 minutes can help you relieve the pain you feel. You can also use cloth dipped in hot water to massage the area, this should be done for at least 15 to 20 minutes. Be careful how long you use these things on your knee as the hot cloth can cause burn while the ice pack can make your knee numb.
(2) Over-the-counter medicine : Anti-inflammatory medicines like ibuprofen and naproxen can be used to reduce the pains. You should be careful how you take these drugs especially if you have ulcer.
HOW TO TREAT PINCHED NERVE IN KNEE
Reducing the pain should not be the end, you should also treat the cause of the pinched nerve to avoid reoccurrence. The most recognized prevalent treatment are:
- Orthotic boot: This can be used to keep your foot in a neutral position so you can walk normally. If your nerve has made your gait to be affected, an orthotic boot can help.
- Corticosteroid injection: Corticosteroids are steroids that are used to treat diseases like arthritis or rheumatism. The corticosteroid is injected to reduce the inflammation of the nerves and this can reduce the pressure.
- Surgery: If your nerves are compressed due to fracture, injury or tumor, a surgery can be performed. If conservative treatment does not work, a procedure called peroneal nerve decompression can done to remove the pressure on your nerve ( Healthline.com). Surgeries are mostly needed if the nerves have been pinched for a long time.
- Physical therapy : After surgery has been done on the knee to treat the root cause of the pinched nerve, therapy is mostly required to correct your posture and strengthen how you walk.
HOW LONG DOES IT TAKE TO HEAL AFTER TREATMENT
The most important thing is to correct the root cause of this pinched nerve, after that, the nerve will start getting better. It can take days or weeks for the compressed nerve to get better. After surgery, the symptoms will go away on its own within some days. The recovery process after the surgery can take about four months.
Pinched nerve in the knee is caused by compression and pressure on the nerves. It can be very painful and can make daily activities like walking and standing difficult for you. Pinched nerve can go on its own but if the pain and symptoms persist, you can seek help. It can be treated using methods like surgeries, therapies, injections and orthotic boot. You can also reduce the pain with drugs and hot or ice packs.