One of the most common causes of pain in the outside of the knee, or lateral knee pain, is iliotibial band syndrome. This is an overuse injury caused by excess friction between the band’s tissue and the underlying bone, usually during high impact activities. The lateral meniscus, which is important for cushioning impact through the joint, can cause pain if it is torn or damaged. Other potential causes of pain in this area include patellofemoral syndrome, osteoarthritis, and referred pain from the lumbar spine.
Iliotibial band (IT band) syndrome, a condition that often affects runners, is one of the most common causes of pain in the outside of the knee. The IT band runs from the hip down the side of the leg before attaching below the knee. If this band is too tight, it can rub against the bone and become inflamed, resulting in lateral knee pain that gets worse with activity. Treatment for this condition involves reducing inflammation and increasing the flexibility of the IT band.
Pain can also be caused by problems with the lateral meniscus. There are two menisci in the knee, with one band located on either side of the joint. If the outer meniscus becomes damaged, often due to sudden sharp turns or long-term degeneration, this will result in pain and swelling. Treatment for a lateral meniscus tear depends on the severity of the problem, with the worst cases requiring surgery and a lengthy break from activity.
Patellofemoral syndrome is sometimes known to cause pain in the outside of the knee. This is a condition involving excess pressure on the knee or poor tracking of the patella, and it is often seen in runners. Depending on the nature of the injury, the pain from patellofemoral syndrome can occur on both the inside and outside of the knees as well as directly beneath the kneecap. Treatment for this condition starts with relative rest and anti-inflammatory measures, along with physiotherapy techniques such as strengthening the quadriceps and taping the patella.
There are a number of other potential causes of this type of knee pain. Osteoarthritis, for example, is known to cause pain both directly beneath the patella and on the sides. In some cases, pain may be referred from other areas of the body. Injuries to the lower spine or hip can sometimes be felt in the knee, for example.