The iliotibial band is the tendon attachment of hip muscles into the upper leg (tibia) just below the knee to the outer side of the front of the leg. Where the tendon passes the knee (lateral femoral condyle) there is a bursa sac between the bone and the tendon. This tendon moves over a bony bump at the outer knee as it passes in front and behind it. The bursa functions like a water balloon to reduce friction and wear of the tendon against the bony bump. In this condition, overuse causes excessive friction at this bump, resulting in inflammation and pain of the bursa (bursitis), tendon (tendinitis), or both.
Iliotibial band syndrome is caused by excessive friction of the iliotibial band and the underlying bursa due to repetitive knee-bending activities. This is an overuse injury, although direct trauma to the outer knee may cause the bursa to get inflamed. Often the deceleration of running down hills may lead to the excessive friction.
Initial treatment consists of medication and ice to relieve the pain, stretching and strengthening exercises (particularly the iliotibial band), and modification of the activity that initially caused the problem. These all can be carried out at home, although referral to a physical therapist or athletic trainer for further evaluation and treatment may be helpful. An orthotic (arch support) for those with flat feet or a wedge for the shoe for those with tight iliotibial bands may be prescribed to reduce friction to the bursa. A knee sleeve or bandage may help keep the tendon and bursa warm during activity and reduce some symptoms. Training techniques can be altered by lessening the amount of the training activity, changing the stride length, avoiding running on hills or stairs, changing the direction you run on a circular or banked track, or changing the side of the road you run on if you run next to the curb in the same direction all the time. Cyclists may need to change the seat height or foot position on their bicycles. An injection of cortisone into the bursa may be recommended. Surgery to remove the inflamed bursa and part of the scarred or inflamed iliotibial band is usually only considered after at least six months of conservative treatment.