There are a variety of causes of inner knee pain. Many of them can be linked to an
injury. Some of the most common incidents that cause knee injury and pain include falls, sports injuries, or increased activity.
Adults — particularly those older than 60 — are most likely to experience knee pain.
Here are seven of the most common possible causes of inner knee pain.
1. Osteoarthritis (OA) Osteoarthritis (OA) is a degenerative disease that breaks down cartilage, causing the bones in your joints to grind together. If you experience inner knee pain while putting pressure on your joint, such as when walking up and down stairs or sitting down in a chair, you may have OA. Because this pressure causes the pain, your symptoms may get more severe as the day goes on.
2. Rheumatoid arthritis (RA) Rheumatoid arthritis (RA) is an autoimmune disease that can also cause inner knee pain. RA causes inflammation in your joints, so people with RA may experience severe inner knee pain in the morning, with symptoms decreasing throughout the day.
3. Medial collateral ligament (MCL) injury The medial collateral ligament (MCL) runs along the outside of your inner knee to stabilize the joint. If the ligament overstretches, you may have an MCL sprain. The MCL can also tear partially or fully. An MCL injury most commonly occurs after force is applied to the outer knee, such as in contact sports.
Symptoms of an MCL injury include:
instability while standing or walking
a popping sound at the time of impact
4. Medial meniscus injury The meniscus is cartilage that provides a cushion between bones in a joint. There are two menisci in each knee. They serve as cushions between your thigh and shin bones. Your meniscus can tear or become damaged if your knee is rotated or put under pressure, most commonly during sports or athletic activities.
There are four major types of meniscus tears:
Depending on the severity of the injury, you may also feel:
a sharp pain when twisting your knee
sense of imbalance
5. Pes anserine bursitis A bursa is a small, fluid-filled sac that helps reduce friction between joints. There are several bursae located throughout your body.
Bursae are also located in your knees between the MCL and three tendons: the sartorius, gracilis, and semitendinosus. They’re collectively called the pes anserinus. If the bursa becomes overused or irritated, it can produce extra fluid that causes swelling and pressure on your knee. This inflammation is known as pes anserine bursitis.
According to the American Academy of Orthopaedic Surgeons, there are several causes of pes anserine bursitis:
medial meniscus tear
turning out your knee or lower leg while standing or walking
tight hamstring muscles
6. Medial plica irritation Plica are small folds in the joint lining. Medial plicae cover your inner knee. Overuse, such as from repeatedly flexing your knee, can irritate the medial plicae.
This causes the folds to thicken and become stuck between the bones. In addition to dull inner knee pain, you may experience locking knees and possibly a cracking sound. Learn more about plica syndrome.
7. Knee contusion If you suffer a direct blow to your knee, such as a being hit by a blunt object or falling hard, you could bruise your knee bone. This is also known as a knee contusion.
A knee contusion could cause inner knee pain, depending on where you were hit. Other symptoms of knee contusions include:
trouble bending the knee