There can be a number of different symptoms of knee nerve damage, but the most common include pain, numbness and tingling, and feelings of burning on or around the kneecap. Some people may also find that they have a hard time moving the joint, or they may feel stiffness or a dull ache when the leg bends in certain ways. Discoloration around the site of the damage is common, too, particularly if the nerve damage was caused by some sort of trauma. A number of different nerves run through the knees, but diagnosing damage can be somewhat tricky. Symptoms are often really similar to other joint problems, including cartilage damage and issues related to arthritis. In general, medical professionals recommend that anyone who suspects they may be suffering from knee nerve damage get evaluated and treated.
Nerve Damage Basics
The body’s nervous system is a complex series of chemical signals that course along the nerve pathways bringing messages about sensation and pain to and from the brain. Damage can happen almost anywhere, and is usually a result of injury or trauma. Nerves can get pinched, severed, or twisted, and moving joints like the knee provide many different opportunities for this sort of injury. Local nerves can be pinched or squeezed fairly easily between the bones and ligaments that together form the joint.
Some damage is obvious right from the start. This isn’t always true, though, since the damage may not be immediate. Certain knee injuries build on themselves over time. A person may feel as though he or she has healed, but may not realize till later that that healing has actually compromised the nerve structure, for instance; or, a person may not even realize that there’s been an injury at all till certain signs of nerve damage begin appearing.
Pain that seems to radiate out of the knee is one of the most common symptoms of localized nerve damage. This often comes in varying degrees, and can alternate between throbbing and mild, dull aching. Sometimes moving the leg or changing the knee’s position can alleviate pressure, but not always. A lot has to do with whether the nerve damage is accompanied by inflammation or swelling at the site, and how seriously the nerves were impacted.
Nerves are usually responsible for carrying signals to indicate pain, and when they’re damaged they can respond in exaggerated ways — in some cases transmitting signals of pain that are disproportionate with the extent of the actual injury. Pathways that have actually been severed, on the other hand, sometimes fail to transmit any signals of pain, even if it would otherwise be warranted.
Numbness and Burning
Anther major sign of knee nerve damage is numbness or a lack of sensitivity. Numbness may be localized in the knee, or it might radiate to the upper or lower leg. Some people also describe the discomfort as a prickly “pins and needles” sensation. Tingling tends to come and go, but is usually most common after periods of inactivity.
People who have suffered these sorts of injuries sometimes also describe a feeling of burning just below the skin. Some of this is just perception, but in certain cases there are actual local skin temperature fluctuations that go hand-in-hand with these sensations. The patient's knee may feel warm to the touch, or in some cases colder than usual.
In many cases nerve damage can also restrict a person’s movement. Quick kicks, sharp bends, and other extreme or rapid movements may be delayed or too painful to perform. This is usually a result of muscle constrictions that happen in response to nerve signals indicating damage — which is to say, it isn’t caused directly by the nerves, but it is nonetheless closely related.
Patients with nerve damage to the knee may also experience weakness and immobility. This weakness may involve the knee or the entire leg. In some instances, the leg may buckle under and the patient may feel unsteady or lose his or her balance
It’s also possible for the skin along the top or backside of the knee to become discolored. A bluish tinge surrounding the knee may indicate nerve damage, although the condition does not always cause this. Color changes are most common when the damage has been caused by a trauma that has otherwise left bruising on the skin, and in these cases it can be tough to distinguish between specific causes.
Diagnosis and Treatment Options
Injury to the soft tissue of the knee does not necessarily mean nerve damage has occurred. Ligaments or tendons may have been torn, yet surrounding nerves may be left undamaged. Although a physician or other healthcare expert may recommend a magnetic resonance imaging (MRI) test to determine if there are tears of tendons or ligaments, nerve damage will not always show up on this imaging, and as such still more testing may be required. In most cases these sorts of extreme measures are only taken if there’s no other way to treat a patient’s symptoms.
Care providers often recommend diagnostic tests if symptoms of peripheral neuropathy are present, which are basically more systemic nervous system problems. A test known as an electromyography (EMG) can determine if symptoms are related to knee nerve damage. From there, medical teams can come up with treatment plans. Sometimes physical therapy and rehabilitation can bring a person back to normal, but in other cases more invasive therapies like surgery are necessary. It’s not always possible to reverse nerve damage, and a lot of times the best that can be done is to mitigate the problem and stop it from spreading or getting worse.
Can You Damage a Knee Replacement?
Knee replacement is major surgery, and once you have it done, you want to take good care of it. It's best to avoid high-impact activities, such as running and jumping, after surgery, especially if the prosthetic joint is cemented in place. Jostling your new knee could cause it to loosen from the bone and eventually fail.
Although you don't want to put too much wear and tear onto your knee replacement, that doesn't mean that you should sit back and relax. The best thing you can do for your knees is exercise to strengthen your core and quadriceps and maintain a healthy weight. You should also minimize your fall risk by using handrails on stairs and ramps, avoiding walking on slippery surfaces, and using a shower chair.
Does Squatting Damage Your Knees?
Although doing squats can cause pain in people who already have bad knees, there is no evidence that squatting damages otherwise healthy knees. Squatting is an excellent way to strengthen your knees and the leg muscles surrounding them. Feel free to squat if you need or want to. If you're going to do squats for exercise, be sure that your form is good, so you don't injure yourself. Try starting with your back against the wall if you find squats difficult. Wall squats are easier to do while you build up your quad muscles to the point where you can do them without the wall. If you want to add weights to your squats, be sure to start small and add more weight gradually, and always use a spotter.
Can Knee Replacement Cause Nerve Damage?
In rare cases, knee replacement surgery can lead to nerve damage. Symptoms include decreased range of motion in the affected leg, pain, and reduced strength. However, this is very rare, and more than half the patients who experience it fully recover without further surgery.
Localized pain, decreased strength, and reduced range of motion are typical and expected after knee replacement surgery, so don't assume that you have a damaged nerve when you experience these things. Eventually, you can get your strength and flexibility back with time and physical therapy.
How Can You Avoid Needing a Knee Replacement?
If you need knee replacement surgery, putting it off will only complicate your life. You'll likely experience more pain and a reduced ability to get around and do the things you need to do. However, if your joints are not yet to the point of needing total replacement, or if you currently have no issues in your knees and want to keep in that way, there are a few things that can help.
Perform Weight-Bearing Exercise
Although joints naturally wear out as a person ages, the best thing you can do to protect your knees throughout your life is strengthen the muscles that support them. Work your quadriceps and hamstrings at least a couple of times per week by doing things like lunges and squats as well as climbing stairs. Or try swimming, elliptical training, or water aerobics. You don't have to become a gym rat or professional bodybuilder to reap the benefits of a lower-body workout. If you're new to exercising, always start small and work your way up to longer sessions. Don't forget to warm up before working out and then stretch again afterward. Doing this helps prevent injuries.
Maintain a Healthy Body Weight
For every pound of body weight, your joints can be under four to six pounds of pressure. As you can imagine, carrying extra weight can be extremely hard on your joints. By this calculation, losing just five pounds could take 20 to 30 pounds of pressure off your knees. Losing weight isn't always easy, but it's worth it. If you have had an inactive lifestyle until now, try building a new habit of walking every day. It doesn't have to be far or fast; just start. Try incorporating more fruits, vegetables, whole grains, and legumes (like beans and peas) into your diet.
Wear Supportive Shoes
The way you walk affects wear and tear on your joints. If your walking posture is not good, perhaps because of ill-fitting shoes, it could cause your joints to wear out faster. If your feet and ankles are not stable and well-supported, your knees will be under too much strain as you walk. If you walk with an uneven gait, for example, favoring one leg or turning your toes inward, you may need corrective shoes or insoles from a podiatrist.