Pain on the inside (medial) aspect of the knee

The most likely structures medially are knee ligaments, muscle tendons, bones, cartilage, bursae and fibrous tissue. Pain may be the result of sporting injury, fracture, sudden overuse or normal age related changes. Knee pain has been linked to obesity, having flexible joints and is more common in teenagers and young adults. Short tight muscles or muscular weakness may also cause or refer pain to the knee plus, spinal conditions ‘sciatica’ can refer pain to the joint.

Medial collateral ligament (MCL)

The MCL provides stability for the inside of the knee connecting the thigh bone to the shin bone. A strong band of tissue the MCL generally restricts rotation at the knee and separation of the thigh bone from the shin bone. The most common causes of MCL pain are strains caused through sports and activities where pivoting is required (Tennis, football…) or through trauma where the ligament has been forced beyond its limits.

Torn cartilage (Meniscal injury)

The meniscal cartilages act as shock absorbers between the thigh bone and shin bone. Semi-circular in shape that sit on the very top of the shin bone providing extra stability and facilitating smooth movement of the joint. The meniscus can be damaged through rotation of the knee on a planted foot which is a common occurrence in many sports and occupations. If you rupture or sufficiently strain the MCL you are likely to tear the medial meniscus cartilage as they are closely connected.

Anterior cruciate ligament injury (ACL)

You will know when you have injured this ligament as it occurs during sudden rotation of the knee such as direction change in tennis or football and commonly skiing also. If you stay away from sport you are unlikely to have a problem. One of the main ligaments within the knee joint its purpose is to provide stability between the thigh and shin bone. Complete rupture may require surgical repair, a stretched ACL will not require surgery, in both cases dedicated prolonged rehabilitation is required to regain stability, strength and be able to consider a return to sporting hobbies.

Osteoarthritis (OA)

Osteoarthritis commonly affects the knees. A healthy joint is made up of two bones whose ends are covered in a shiny smooth coating of cartilage which in part allows the joint to slide, glide and rotate providing functional movement. The cartilage within each joint is bathed in synovial fluid which nourishes the cartilage, maintaining good health and further providing shock absorption.
Over time our knee joints, essentially our cartilage may become worn like the tread on a tyre following years of bending, straightening and bearing weight. Our bodies attempt to repair the cartilage however are unable to replace cartilage tissue like-for-like with the shiny smooth cartilage slowly being replaced with rough bone. The change in joint structure causes symptoms of stiffness, swelling and pain most commonly on the medial side of the knee that is known as osteoarthritis. Most common in the over 50’s.

Bursitis (Pes Anserine)

Bursae are small fluid-filled cushions that serve to reduce compressive friction caused by muscle tendons in this case the hamstring tendons, and ligaments as they pass over bone. When repetitive friction occurs the bursae become inflamed causing bursitis which can be painful. Can be considered an overuse injury, possibly due to increasing sporting hobbies and associated with rheumatoid arthritis and gout.

Plica Syndrome

The Plica is an embryonic tissue inside the medial aspect of the knee that becomes inflamed with sudden increase in activity giving acute medial knee pain.