According to the Mayo Clinic, knee pain can come from damage to any of the tissues that compose the knee joint. Knee pain occurs on all sides of the knee, and the location of a person's knee pain often helps the physician diagnose the problem to establish the appropriate course of treatment. The knee joint is one of the body's most complex joints, and one if it's most vulnerable.
Lateral Knee Pain
According to the American Academy of Family Physicians, known as AAFP, lateral knee pain, or pain on the outside edge of a person's knee facing away from the body, may be caused by one or more of three principle factors: a lateral collateral ligament sprain, a lateral meniscus tear or iliotibial band tendonitis.
Injury of the lateral collateral ligament is less common than injury of the medial collateral ligament, and typically is caused by excessive varus or outward stress applied to the knee. The person will feel pain immediately and will be forced to stop their activity.
A lateral meniscus tear happens when a person experiences a sudden twisting of their knee, which may happen when a runner spontaneously changes direction. Those with lateral meniscus tears often report recurrent knee pain and bouts of knee joint catching or locking.
Iliotibial band tendonitis is the result of excessive friction between the iliotibial band and the lateral femoral condyle of the knee. It's a common musculoskeletal complaint in endurance athletes, including runners and cyclists.
Medial Knee Pain
According to the AAFP, medial knee pain, or pain on the inside of the knee, may be caused by one or more of the following factors: medial collateral ligament sprain, a medial meniscus tear, pes anserine bursitis or medial plica syndrome.
Medial collateral ligament sprains are relatively common, and are often caused by acute, blunt force trauma. A person with a suspected medial collateral ligament sprain will have experienced excessive valgus or inward stress on their knee, immediately followed by pain and swelling on the inside of the knee. A medial meniscus tear is similar to a lateral meniscus tear, in that the involved knee joint will have bouts of catching or locking, especially when the person squats or twists their knee.
Pes anserine bursitis occurs when the structures on the inside of the knee--the tendinous aspects of the sartorius, gracilis and semi-tendinosus muscles--inflame the per anserine bursa. Medial plica syndrome occurs when the plica, a fold of the knee's synovial membrane, become inflamed with repetitive activities and overuse.
Anterior Knee Pain
According to the Clinical Sports Medicine website, anterior knee pain, or pain on the front of the knee, is common among patients in a sports medicine practice. Causes of anterior knee pain include one or more of the following: dislocation or subluxation of the kneecap, tibial apophysitis, jumper's knee or patellofemoral pain syndrome.
Patellar subluxation causes the knee to give out or buckle, and occurs more frequently in girls and young women, due to the anatomy of the female knee. Tibial apophysitis, also called an Osgood-Schlatter lesion, may cause bouts of knee pain that are made worse by squatting and walking up or down stairs. Tibial apophysitis is most common in teenage boys who have recently experienced a growth spurt.
Like tibial apophysitis, jumper's knee, which involves inflammation of the patellar tendon, it is most common in teenage boys following a growth spurt. Running and stair climbing provoke anterior knee pain in those with jumper's knee.
People with patellofemoral pain syndrome complain of a mild to moderate anterior knee pain that occurs after prolonged sitting. Patellofemoral pain syndrome is more common in women.
Posterior Knee Pain
The posterior or back of the knee is a less common site for knee pain than other locations. The AAFP states that posterior knee pain may be caused by one or both of the following factors: a popliteal or Baker's cyst, or a posterior cruciate ligament injury. A Baker's cyst is a benign swelling of the semimembranosus bursa.
According to the Mayo Clinic, patients with a Baker's cyst typically experience mild to moderate knee pain, along with swelling behind the knee and knee stiffness.
The Sports Injury Clinic website states that posterior cruciate ligament or PCL tears will occur when a person experiences direct impact on the front of their tibia or shin bone, usually when their knee is bent. Tackles and collisions or falling with a bent knee are common causes of PCL tears. These tears cause pain, swelling and instability in the involved knee joint.
