Knee pain is one of the most common musculoskeletal complaints, affecting individuals of all ages and activity levels. Inner knee pain, in particular, can be especially frustrating, as it often disrupts daily activities and makes it difficult to move with ease. Understanding the root causes of inner knee pain can help you identify the issue more accurately, seek appropriate treatment, and find relief from the discomfort. In this article, we’ll explore seven of the most common causes of inner knee pain, their symptoms, and what you can do to address them.
1. Medial Collateral Ligament (MCL) Injury
The Medial Collateral Ligament (MCL) is a strong band of tissue on the inner side of the knee that helps stabilize the joint and prevent it from buckling sideways. The MCL connects the femur (thigh bone) to the tibia (shin bone) and plays a crucial role in keeping the knee stable during activities like running, jumping, or turning.
What It Is:
An MCL injury is often caused by trauma, such as a blow to the outer side of the knee (often seen in contact sports like football or skiing). It can also occur from a sudden change in direction or overuse, especially if the knee is forced into an unnatural position.
Symptoms:
- Pain on the inner side of the knee, which may worsen with bending or straightening the leg
- Swelling around the knee joint
- A feeling of instability, as if the knee is “giving way”
- Tenderness along the ligament
Treatment:
MCL injuries can range from mild sprains to more severe tears. Mild sprains often heal with rest, ice, compression, and elevation (the R.I.C.E method), along with physical therapy to strengthen the knee. More severe injuries may require bracing or, in rare cases, surgery.
2. Medial Meniscus Tear
The meniscus is a wedge-shaped piece of cartilage that provides cushioning and support between the femur and tibia. Each knee has two menisci—one on the inside (medial) and one on the outside (lateral) of the joint. A tear in the medial meniscus is one of the most common causes of inner knee pain.
What It Is:
A medial meniscus tear typically occurs due to sudden twisting or rotating motions, often during sports or heavy lifting. The tear can be caused by acute trauma or gradual wear and tear over time, particularly in older adults.
Symptoms:
- Pain in the inner knee, especially when twisting or rotating the leg
- Swelling and stiffness in the knee
- A popping sensation at the time of the injury
- Limited range of motion and difficulty straightening the knee
- A feeling of the knee “locking” or “catching”
Treatment:
Treatment for a meniscus tear depends on the severity and location of the tear. Non-surgical treatments include rest, ice, physical therapy, and anti-inflammatory medications. In cases where the tear is severe or does not respond to conservative treatment, arthroscopic surgery may be needed to repair or remove the damaged meniscus.
3. Pes Anserine Bursitis
The pes anserine is a group of three tendons from the muscles of the inner thigh (the sartorius, gracilis, and semitendinosus muscles) that attach to the tibia. The pes anserine bursa is a fluid-filled sac that helps reduce friction between the tendons and the underlying bone. When this bursa becomes inflamed, it can cause significant pain on the inner side of the knee.
What It Is:
Pes anserine bursitis is often caused by overuse, particularly in athletes or individuals who engage in activities that involve repetitive knee motions, such as running or cycling. It can also occur due to sudden weight gain or poor knee alignment.
Symptoms:
- Pain on the inner side of the knee, just below the joint
- Swelling and tenderness in the affected area
- Pain that worsens with activity, particularly during squatting, climbing stairs, or rising from a seated position
- Tightness or stiffness in the knee
Treatment:
Conservative treatments are typically effective for pes anserine bursitis. Rest, ice, and over-the-counter pain medications can help reduce inflammation. Physical therapy focusing on strengthening the quadriceps and improving flexibility may also be beneficial. In severe cases, corticosteroid injections or aspiration of the bursa may be considered.
4. Osteoarthritis of the Knee
Osteoarthritis (OA) is a degenerative joint disease that occurs when the cartilage that cushions the knee joint wears down over time. This condition is common among older adults but can affect younger individuals who have had knee injuries or have certain genetic factors.
What It Is:
Osteoarthritis of the knee can cause pain, stiffness, and swelling in the joint. In the case of inner knee pain, OA typically affects the medial (inner) side of the knee first. The loss of cartilage leads to bone-on-bone friction, resulting in inflammation and pain.
Symptoms:
- Chronic pain on the inner side of the knee that worsens with activity and improves with rest
- Stiffness, particularly after periods of inactivity (e.g., in the morning or after sitting for long periods)
- Decreased range of motion in the knee
- A feeling of grinding or popping when moving the knee
Treatment:
There is no cure for osteoarthritis, but treatment can help manage symptoms and slow disease progression. Non-surgical treatments include weight management, physical therapy, anti-inflammatory medications, and the use of braces or supports. In more advanced cases, surgical options such as knee replacement may be necessary.
5. Patellofemoral Pain Syndrome (Runner’s Knee)
Patellofemoral pain syndrome (PFPS), often referred to as runner’s knee, is a condition that causes pain around or behind the kneecap (patella). While the pain is usually felt in the front of the knee, it can sometimes radiate to the inner side, particularly when the knee is under stress or pressure.
What It Is:
PFPS typically occurs when the patella is misaligned or moves abnormally over the femur, causing irritation of the cartilage behind the kneecap. This condition is commonly seen in athletes, especially runners, cyclists, and individuals who engage in high-impact activities.
Symptoms:
- Pain around or behind the kneecap, with possible radiating pain to the inner side of the knee
- Pain that worsens with activities like squatting, jumping, or climbing stairs
- A feeling of instability or weakness in the knee
- Swelling or a sensation of fullness in the knee
Treatment:
Treatment for PFPS involves strengthening exercises for the quadriceps and hip muscles, as well as improving flexibility in the surrounding muscles. Ice, rest, and anti-inflammatory medications can help manage pain and swelling. In some cases, orthotics or knee braces may be recommended to improve alignment and reduce strain on the patella.
6. Tendinitis of the Knee
Tendinitis refers to the inflammation of a tendon, which is a thick cord of tissue that connects muscle to bone. In the knee, the patellar tendon, which connects the kneecap to the shin bone, is most commonly affected. Tendinitis can occur on the inner side of the knee if the tendons involved are strained or overused.
What It Is:
Knee tendinitis, also known as patellar tendinopathy or “jumper’s knee,” is often caused by repetitive activities that place stress on the knee joint, such as running, jumping, or heavy lifting. It can also occur from sudden trauma or incorrect movement patterns during physical activities.
Symptoms:
- Pain along the inner knee, particularly below the kneecap
- Tenderness and swelling in the affected tendon
- Pain that worsens with activity, particularly jumping or running
- A feeling of weakness or instability in the knee
Treatment:
Treatment for tendinitis includes rest, ice, anti-inflammatory medications, and physical therapy focused on strengthening the quadriceps and improving tendon flexibility. In severe cases, corticosteroid injections or platelet-rich plasma (PRP) therapy may be considered.
7. Baker’s Cyst
A Baker’s cyst is a fluid-filled swelling that develops behind the knee, typically as a result of another knee condition such as arthritis or a meniscus tear. The cyst can cause swelling and discomfort on the back or inner side of the knee, often leading to a feeling of tightness or fullness.
What It Is:
Baker’s cysts are most commonly caused by joint issues that lead to an accumulation of excess synovial fluid (the fluid that lubricates the knee joint). When the fluid accumulates, it can form a lump or cyst at the back of the knee, which may also radiate pain to the inner side of the joint.
Symptoms:
- Swelling and tenderness behind the knee, which may extend to the inner knee
- Tightness or stiffness in the knee, particularly when bending
- Pain that worsens with activity or prolonged standing
- A noticeable lump behind the knee
Treatment:
Treatment for a Baker’s cyst may involve addressing the underlying cause, such as treating arthritis or repairing a meniscus tear. Non-surgical treatments include rest, ice, and anti-inflammatory medications. In some cases, draining the cyst or injecting corticosteroids may be recommended.
Conclusion
Inner knee pain can be caused by a wide variety of conditions, ranging from injuries to chronic conditions like osteoarthritis. Understanding the underlying cause of your pain is the first step toward finding an effective treatment plan. Whether it’s a ligament injury, a meniscus tear, or a more complex issue like tendinitis or arthritis, early intervention can prevent further damage and help you regain function and mobility. If you’re experiencing persistent or worsening knee pain, it’s important to consult with a healthcare professional to receive a proper diagnosis and develop a treatment plan tailored to your specific needs.