Common Causes of Knee Pain
There are many potential causes of knee pain. A proper diagnosis is crucial to ensuring you receive the most effective treatment for your condition.
In some instances, your knee pain may be caused by an injury associated with a one-time event. These include:
- Fractures – A sudden blow to the knee may cause one of your leg bones to break at the joint. This most commonly occurs in sports injuries, vehicle accidents and serious falls.
- Dislocations – A dislocated knee occurs when one of the bones connected to this joint gets knocked out of place. This injury can cause neurovascular damage and become limb threatening. This is an uncommon injury.
- Sprains and strains – Stretched or torn ligaments result in a sprain. Stretched or torn muscles result in a strain. These injuries occur when you place too much pressure on your muscles and ligaments, which is common when participating in sports. The knee has many associated ligaments, and any one can cause pain. The most common injuries include:
- Anterior cruciate ligament (ACL) – This ligament controls forward movement of the tibia (shin). This is the most commonly injured ligament, and injury occurs via a quick twisting movement of the knee while the foot is planted.
- Medial collateral ligament (MCL) – This ligament gives stability to the inner part of the knee. Injury occurs with a blow to the outside of the knee joint.
- Meniscus – There are two C-shaped menisci in the knee. Injury occurs with forceful twisting of the knee with full weight on that leg.
Repetitive motions can result in significant wear and tear to your knee. These injuries often occur in work environments or from athletic activities, and they can be quite painful. Common examples of repetitive motion injuries include:
- Bursitis – The bursa providing cushioning to your knee can fill with fluid and become swollen from repetitive movements, causing redness and sensitivity. It can also be damaged from trauma associated with a fall, or with excessive time kneeling.
- Tendonitis – The tendons in your knee can become damaged from overuse. “Patellar tendonitis” is the most common. This will cause pain along the front of your knee.
You may also develop repetitive use injuries from flexion and extension movements, especially with added weight, as with squatting or lunging. These motions can cause irritation and damage to the joint, resulting in increased pain.
Damage to the nerves in the knee are uncommon. The main nerve injury in the knee joint includes:
- Peroneal nerve compression – This is caused by compression or damage to the peroneal nerve, a branch of the sciatic nerve. It is often associated with numbness or burning sensations along the outside of the knee and extending down the outside of the lower leg. In severe cases, you may experience weakness of the foot. This most commonly is caused by sitting with your legs crossed.
Arthritis can develop from inflammation of the knee joint, causing pain and stiffness which gets worse over time. The most common types of arthritis impacting the knee include:
- Rheumatoid arthritis – This occurs when your immune system attacks your knee joint, causing swelling and pain.
- Osteoarthritis – This develops when the cartilage in your knee breaks down, causing the bones to rub together. The knee joint is the most commonly affected joint. Osteoarthritis results in pain and stiffness in the knee.
Infection and Blood Clots
While less common, you may experience knee pain from infection in the joint or the tissue surrounding the joint. Blood clots in the leg can also cause knee pain. These conditions can also result in redness, swelling and fever.