Pain at the inner aspect of the knee (also referred to as medial knee pain) can be the result of a variety of conditions. It can happen suddenly after a fall, twisting injury, or gradually over time. The most common causes of inner knee pain that we see in our practice are:
What are the causes of pain at the inside of the knee?
Knee arthritis (osteoarthritis)
Knee Osteoarthritis is a degenerative condition that results from progressive wear and tear changes within the joint, resulting in thinning or loss of the articular cartilage. The cartilage is the protective tissue that covers the bone surfaces at the joints to ensure smooth and frictionless movement. In severe cases, the bones will be exposed and start to rub against each other, resulting in joint pain, reduced movement and sometimes crepitus (a grating sensation due to bone rubbing on bone). Knee osteoarthritis is often associated with fluid build-up within the joint resulting in joint swelling. This is referred to (joint effusion).
Knee arthritis is more commonly seen in the inner aspect of the knee. It is more common in people over 50 but can also happen in the younger population, especially if they have sustained a previous injury. A knee X-ray is very useful for the assessment of suspected knee arthritis. The treatment usually consists of physiotherapy, anti-inflammatory tablets and ultrasound-guided injection therapy, including knee cortisone injections, PRP and Hyaluronic acid injections.
Meniscal tear (medial)
The meniscus is a special supportive C-shaped cartilage that cushions and increases joint stability. There are two menisci in each knee (a lateral meniscus at the outer aspect of the knee joint and a medial meniscus at the inner aspect of the knee joint). Meniscal injury usually results from a sudden twisting injury but can happen progressively without significant trauma. In addition to pain, other features of a medial meniscal tear include swelling at the inner knee and sometimes locking of the joint. Giving way (feeling of the knee going under you) can also happen. The treatment depends on the type of tear. A knee MRI examination would provide very accurate assessment of the menisci. Some require surgical treatment, while others are treated conservatively with physiotherapy and ultrasound-guided intra-articular injection therapy. To find out more, please see our article about meniscal tears.
The knee cap (patellofemoral) joint pain
The patellofemoral joint is the part of the knee joint just behind the knee cap. Wear and tear changes here would lead to pain at the front of the inner aspect of the knee cap. Although this is usually seen in the older population, young people also can suffer from patellofemoral joint pain. This can happen due to increased activity that involves the knee cap (patellofemoral joint), like cycling and running. In this case, the thinning to the articular preferentially affects the knee cap and is referred to (Chondromalacia patellae). In addition, patellofemoral joint pain can happen in young people who have a predisposition for instability of the patellofemoral joint (due to altered anatomy of certain bones and tendons within the knee). This is referred to as patellofemoral joint dysplasia. The treatment for patellofemoral joint osteoarthritis and chondromalacia changes usually consists of exercise modification and physiotherapy. Please read our article if you think you have patellofemoral joint (knee cap) osteoarthritis.
Medial collateral ligament (MCL) sprain
This is an important structure that runs at the inner aspect of the knee between the femur and the shin bone. It can undergo injury secondary to direct impaction or twisting movement. The injury is usually divided into grades 1 and 2 (partial) and grade 3 (complete injury). MCL sprain is more common at its upper attachment. It can be associated with other ligamentous injuries (like the menisci and the anterior cruciate ligament), and therefore, it is important to have an appropriate clinical assessment and further knee imaging. A knee ultrasound scan is very useful in assessing suspected MCL injury. A knee MRI examination is preserved when there is suspicion of multiple injuries and internal derangement. Please see our article about knee ultrasound vs MRI for more information. Partial MCL injuries are usually treated conservatively, while complete injuries may require surgical treatment.
Pes anserine bursitis
The pes anserine refers to the three tendons with a combined attachment at the inner aspect, just below the knee. Pes anserine tendinosis results from inflammation of these tendons. Sometimes the term bursitis is also used. This refers to inflammation of the bursa (a thin fluid-containing sac) between the tendons and their attachment to the bone. The two conditions can overlap. To learn more, please see our article about Pes anserine bursitis/tendinosis. The management usually starts with physiotherapy. Ultrasound-guided injection treatment (usually cortisone) can be useful in the management.
Referred pain from the hip or spine
Impingement or irritation to the nerves within the spine can cause pain felt within the hip or knee joint. Usually, there will be an element of back pain as well here, and the clinical assessment and imaging of the knee will be normal, pointing to pain due to other causes. This is called (referred pain) as it comes from a different source.
Summary
There are a few causes for pain in the inner aspect of the knee. Clinical assessment and imaging would be very useful in establishing the diagnosis. Ultrasound is usually the first modality for the assessment, followed by MRI. MRI can give very valuable information about the inner structures within the joint. The treatment depends on the underlying cause. While significant injury to the ligaments or menisci may require surgery, other conditions can usually be managed conservatively with physiotherapy, exercise and anti-inflammatory tablets. Ultrasound-guided knee injection therapy can be useful in managing some of these conditions.
Knee conditions and treatment
