Knee pain can be a complex issue that stems from multiple causes rather than just one. Some types of knee pain are more common than others depending on the population (e.g. rugby players, marathon runners, older and sedentary adults). It can be caused by external factors, like getting hit to the side of the knee, or internal factors, like arthritis and nerve impingements. This page categorizes different types of knee pain based on anatomy and location of the symptoms. Each category examines what is known about certain types of knee pain and the evidence behind certain treatments.
Anterior knee pain
Pain in the front of the knee is one of the most common bane for many pain, especially running athletes. Some common types of anterior knee pain include:
Jumper’s knee: Also known as patellar tendinopathy, jumper’s knee is often caused by repetitive landing, jumping, acceleration, and deceleration that increase the risk of getting tears in the patellar tendon.
Patellofemoral pain syndrome: Sometimes called “runner’s knee,” PFPS is generally felt in the front of the knee, usually beneath or around the kneecap. While it sometimes comes and goes or it can go away by itself, PFPS can become chronic and can impede or discourage people from exercise or simply moving.
ACL tear: One of the most common type of knee injury and source of pain in the front of the knee, a tear of the anterior cruciate ligament (ACL) can cost an athlete’s career. Like jumper’s knee, pivoting, turning, and sharp movements of the knee increase the likelihood of getting an ACL tear.
While pain the back of the knee is less common than other parts of the knee, the approach to understanding knee pain and its treatments are not that different. Posterior knee pain can stem from not only nerves or inflammation of the tissues in the back of the knee but also from other body parts, such as the hamstrings.
Baker’s cyst: Enlargement of the popliteal cyst—or Baker’s cyst—can cause pain behind the knee by tissue inflammation, nerve impingement, or a combination of various factors.
PCL tear: Injuries to the posterior cruciate ligament (PCL) is less common than other ligament injuries, but there is ample research to both clinicians and patients to decide which treatments are best.
Hamstring strain: This is a tear in the hamstring muscle, usually toward the pelvis, where symptoms may radiate to the back of the knee.
Deep vein thrombosis: Oftentimes called “DVT,” this is blood clot along one of the veins that run along from the hip to the lower leg. Symptoms may be pain behind the knee with swelling and reddish, hot skin at the site of the clot. This requires immediate medical attention and a change in lifestyle to minimize the risk of a recurrence.
Medial knee pain
Medial meniscus tear: tear to the meniscus at the inner knee, often caused by a sharp strike to the outer knee.
MCL injury: Like the medial meniscus tear, injury or tear to the medial collateral ligament are also commonly caused by external force toward the outer knee. However, internal factors, such as pivoting and turning of the knee can increase the risk of a MCL tear.
Pes anserine bursitis: Irritation to the pes anserine bursa can cause it to enlarge and get inflamed. It is a little more difficult to diagnosis and treat because pes anserine bursitis often have overlapping symptoms with other types of knee pain.
Lateral knee pain
Lateral meniscus tear: tear to the meniscus at the outer knee. Like medial meniscus tears, it is often caused by a sharp strike but to the inner knee.
LCL injury: The lateral collateral ligament (LCL) is also prone to injury, most likely in the form of a tear or sprain. Causes are similar to MCL injuries.