Lateral knee pain is pain on the outside of the knee which has come on gradually as opposed to an acute knee joint or ligament injury.
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The most common causes of lateral knee pain are Iliotibial band friction syndrome and lateral cartilage injuries. Below we outline the most widely seen causes of pain on the outside of the knee, less common causes of lateral knee pain as well as important injuries that should not be missed.
Common causes of lateral knee pain
Iliotibial band friction syndrome is inflammation of the Iliotibial band on the outside of the knee as it rubs against the outside of the knee joint. Symptoms include pain over the outside of the knee which will come on gradually over time getting progressively worse until running must stop. Typically the athlete will rest for a period of time until symptoms go only for them to return so far into a run when training resumes.
Lateral cartilage meniscus injury is an injury to the semi circular cartilage on the outside of the knee joint which can be a minor tear or degeneration which happens over time through repeated pressure. Symptoms of a lateral meniscus tear include tenderness and pain around the outside surface of the knee, particularly along the joint line.
Lateral ligament injury is a sprain or tear to the ligament on the outside of the knee. It is usually caused by an impact to the inside of the knee which over stretches the lateral ligament on the outside of the knee joint. Lateral ligament injuries are graded 1 to 3 depending on severity with symptoms ranging from mild tenderness on the outside of the knee to severe pain.
Less common causes of lateral knee pain
Osteoarthritis of the knee is wear and tear on the knee joint and when it occurs in the lateral compartment or outside of the knee then symptoms can include a deep aching pain in the inner knee that is worse after exercise. Stiffness in the joint is common, particularly first thing in the morning however this may reduce with movement as lubricating synovial fluid is produced in the joint. There is likely to be swelling in the knee and sometimes a clicking or cracking noises when moving the knee.
Patellofemoral pain syndrome is usually in the anterior knee pain category causing pain at the front of the knee. However it can cause pain on the outside of the knee as the outside of the patella rubs on the bone underneath. There is likely to be swelling over the knee with pain coming on gradually over time.
Biceps femoris tendonitis is inflammation of one of the hamstring muscles at its point of attachment at the back and outside of the knee. Symptoms include tenderness and swelling where the tendon attaches to the bone. There may be pain when bending the knee against resistance with stiffness after exercise and in the mornings.
Synovitis of the knee occurs when the synovial membrane which lines and lubricates the knee joint, becomes inflamed. Symptoms include pain, swelling and tenderness in the knee joint. The cause of inflammation can vary and include rheumatoid arthritis or gout or simply develop on its own.
Superior tibiofibular joint sprain also known as proximal tibiofibular joint injury is a tear to the ligament which connects the tibia fibula bones at the top near the knee. It occurs most commonly when the athlete sustains an impact or falls with their knee in a fully bent position.
Referred pain from the lumbar spine is where an injury or problem in the lower back results in pain in the knee. This is likely due to pressure on the sciatic nerve causing pain to radiate down in the the leg and knee.
Excessive lateral pressure syndrome
Important do not miss
Peroneal nerve injury is an injury to a branch of the sciatic nerve which runs down the outside of the lower leg which contract the peroneal muscles in the lower leg. Symptoms of a peroneal nerve injury usually include numbness or tingling in the front and or side of the lower leg but pain on the outside of the leg is possible.
Slipped capital femoral epiphysis is a hip injury or fracture to the top of the thigh bone just below the ball of the bone at the top. Pain is usually felt in the hip but can radiate into the knee.
Perthes' disease is a hip condition which affects children aged between four and eight, but can also occasionally occur in younger children and teenagers. Symptoms of Perthes disease include tiredness and pain in the groin but sometimes also in the knee.