Inner knee pain is a common concern, ranging from a dull ache to sharp, debilitating pain. Understanding its causes is the first step toward finding appropriate management and relief. This article explores the anatomical structures involved and the most frequent causes of inner knee pain.
Inner Knee Anatomy
The inner side of the knee, also known as the medial aspect, houses several important structures that contribute to its stability and movement. The medial collateral ligament (MCL) is a strong band of tissue running along the inner knee, connecting the thigh bone to the shin bone and helping to prevent the knee from bending too far inward. The medial meniscus, a C-shaped piece of cartilage, acts as a shock absorber between the bones and helps distribute weight evenly across the joint. Additionally, the pes anserine bursa, a small fluid-filled sac, provides cushioning between tendons and bones on the lower inner knee.
Common Reasons for Inner Knee Pain
A frequent cause of inner knee pain is an injury to the medial collateral ligament (MCL). This ligament can be stretched (sprained) or torn from a direct blow to the outside of the knee or a sudden twisting motion. An MCL injury often results in pain, swelling, and tenderness along the inner knee, sometimes accompanied by instability.
Medial meniscus tears are another common source of pain. These tears can occur acutely from forceful twisting, especially with a bent knee, or develop gradually due to degenerative changes. A torn medial meniscus can cause sharp pain, particularly with twisting or squatting movements, and may lead to catching or locking sensations in the knee joint. Swelling and tenderness along the joint line are common.
Osteoarthritis, particularly affecting the medial compartment of the knee, is a progressive condition that erodes the cartilage cushioning the joint. As cartilage wears down, the bones can rub against each other, leading to pain, stiffness, and reduced range of motion. This type of arthritis commonly causes a deep, aching pain on the inner side of the knee that worsens with activity and improves with rest. Morning stiffness is also a characteristic symptom.
Pes anserine bursitis involves inflammation of the bursa located about two to three inches below the kneecap on the inner side. This inflammation often arises from repetitive friction or overuse, common in activities like running or climbing stairs. The condition causes localized tenderness and pain that intensifies with movement or direct pressure on the bursa. Swelling in the area can also make it uncomfortable to bend or straighten the knee fully.
Other Potential Causes
Pain on the inner side of the knee can originate from less common sources or be referred from other areas of the body. Referred pain from the hip or lower back, for example, can cause discomfort in the knee, even if the knee itself is not directly injured. This occurs because nerves supplying the hip and back also travel down to the knee region. A thorough examination of the entire limb and spine may be needed to pinpoint the true origin of the pain.
Patellofemoral pain syndrome, often associated with pain around or behind the kneecap, can also cause medial knee discomfort. This can happen if an imbalance in kneecap tracking causes increased pressure or friction on the inner aspects of the joint. Nerve entrapment, where a nerve becomes compressed, can lead to burning or tingling sensations on the inner knee. Medial plica syndrome, involving an irritated fold of tissue within the knee joint, can also cause inner knee pain, often accompanied by a snapping sensation.
When to Consult a Professional
Consult a healthcare professional if inner knee pain persists despite initial home care or significantly impacts daily activities. Immediate medical attention is warranted for severe pain, rapidly developing significant swelling, or an inability to bear weight on the affected leg. A locking or catching sensation in the knee, especially if it prevents full extension or flexion, also warrants professional evaluation. Pain that worsens over time, or is accompanied by fever or redness, also requires medical attention.
Initial Home Management
Several home management strategies can provide immediate relief for inner knee pain. The RICE protocol—Rest, Ice, Compression, and Elevation—is often recommended. Resting the knee by avoiding aggravating activities helps reduce stress on injured tissues. Applying ice to the affected area for 15-20 minutes several times a day can help reduce swelling and pain.
Gentle compression with a bandage can further minimize swelling, and elevating the leg above heart level can assist in fluid reduction. Over-the-counter pain relievers, such as nonsteroidal anti-inflammatory drugs (NSAIDs), can also help manage pain and inflammation temporarily.