Iliotibial band syndrome
Iliotibial band (ITB) syndrome (ITBS) is the most common cause of lateral knee pain among athletes. It is an injury to the knee, generally associated with running, cycling, hiking or weight-lifting (especially squats).
Other popular names
- ITB Syndrome / ITBS
- Runner's Knee
Who does it affect?
ITB and usually affects athletes who are involved in sports that require continuous running or repetitive knee flexion and extension. This condition is most common in long-distance runners and cyclists. It may also be observed in athletes who participate in volleyball, tennis, soccer, skiing, weight lifting, and aerobics.
Unlike many overuse injuries, however, IT band pain afflects seasoned runners almost as much as beginners.
Iliotibial Band Syndrome is more common in women, possibly because some women's hips tilt in a way that causes their knees to turn in.
Why does it happen?
ITB syndrome can result from any activity that causes the leg to turn inward repeatedly. This can include wearing worn-out shoes, running downhill or on banked surfaces, running too many track workouts in the same direction, or simply running too many miles. When the iliotibial band comes near the knee, it becomes narrow, and rubbing can occur between the band and the bone. This causes inflammation.
The Ilio Tibial Band (ITB) is a tough length of fascia that attaches to the outer side of the pelvis (which is known as the Ilium), goes down the outer side of the thigh and inserts into the outer side of the shin bone (Tibia). As such, the Ilio Tibial Band forms a length of taught fibrous tissue that connects the hip and knee.
The Lateral Epicondyle is a bony prominence that is the widest point of the thigh bone. When the knee is straight the ITB is in front of the Lateral Epicondyle of the thigh bone and when the knee is fully bent the ITB is behind the Lateral Epicondyle of the thigh bone. During movements of the knee, the ITB moves over the Lateral Epicondyle of the thigh, with maximum friction at 30 degrees of knee bend.
During activities such as running and cycling, where there is repeated bending and straightening of the knee joint, the ITB can 'impinge' upon the Lateral Epicondyle and the resultant friction can lead to inflammation of the tissues. If the ITB is tight, then the degree of friction is increased and a tight ITB can predispose people to Runner's Knee.
Between the ITB and the thigh there is a sac of fluid, called a bursa, which is meant to prevent friction. However, where there are repeated knee bending movements with a tight ITB, the bursa can become impinged between the ITB and the Lateral Epicondyle of the thigh. The bursa itself, as well as the ITB, can become inflamed and painful.
ITBS symptoms range from a stinging sensation just above the knee joint, to swelling or thickening of the tissue in the area where the band moves over the femur. The stinging sensation just above the knee joint is felt on the outside of the knee or along the entire length of the iliotibial band. Pain may not occur immediately during activity, but may intensify over time. Pain is most commonly felt when the foot strikes the ground, and pain might persist after activity. Pain may also be present above and below the knee, where the ITB attaches to the tibia.
Often there is severe tenderness when the Lateral Epicondyle of the thigh bone is palpated. There is usually maximum friction at the area of the Lateral Epicondyle when the knee is bent to around 30 degrees.
An x-ray of the knee will not show Runner's Knee.
It can be picked up on an MRI scan, where there is inflammation and thickening of the tissue.
An Ultrasound scan is usually the most effective way of confirming the diagnosis. If the bursa underlying the ITB is inflamed it can be seen quite easily on the Ultrasound scan, as can inflammation in the surrounding tissue.
- Many cases of Runner's Knee respond well to physiotherapy treatment. The aims of treatment are to resolve the localised inflammatory response and identify and address any underlying postural and body alignment issues that may be contributing to the problem.
- Rest and ice therapy are very important and Non Steroidal Anti Inflammatory Drugs (NSAIDs) can be very helpful where there is acute pain. A Knee Cryo/Cuff Ice Therapy Device can provide excellent pain relief. Stretching of the ITB and the muscles that attach to it (Gluteus Maximus and Tensor Fascia Latae) is undertaken to try and relieve tension in the ITB.
- In cases where rest and ice fail to settle the symptoms fully, then a corticosteroid injection into the area of the bursa over the Lateral Epicondyle of the thigh is usually very effective. Most doctors advise a period of seven days rest following the injection and postural and alignment faults should be corrected before returning to sporting activities.
- In mild cases of Runners Knee a Knee Strap can relieve symptoms very effectively during running. It provides compressive forces above and below the knee cap which reduce tension in the Ilio Tibial Band and the pain associated with Runners Knee.
When conservative therapy does not resolve the pain, surgery may be indicated.
With the knee in 30° of flexion, a longitudinal incision is made centered over the lateral epicondyle. The posterior portion of the iliotibial band (ITB) is then exposed. The knee is flexed and extended to identify the portion of the ITB that is impinging on the lateral epicondyle. A triangular piece of the ITB is then resected. The base of the triangle is approximately 2 cm and centered over the posterior fibers of the ITB. The height of the triangle is roughly 1.5 cm. The knee is then moved through the full range of motion to confirm adequate release of the ITB. The wound is then irrigated and closed. Excision of an elliptical section of the ITB also has been described.
Return to normal routine
Surgical release of the iliotibial band (ITB) is typically successful in eliminating pain. Patients are usually walking reasonably comfortably by 2 weeks and by 6 weeks can generally commence running. It is important not to over-exert too early after the procedure as this can increase the discomfort and swelling. Gradual reintroduction of activities within levels of comfort is recommended. Drive a car is allowed the next day. People with desk jobs can return to work as early as 1-2 days, while people in more heavy manual employment may require 6 weeks.
ITB release is a very safe procedure. The most common side effect is temporary discomfort or slight bruising. Potential postoperative problems with ITB release include infection, blood clots, and an accumulation of blood in the knee. These occur infrequently.
Anything that increases friction between the ITB and the Lateral Epicondyle of the thigh can increase the likelihood of developing Runner's Knee. Because tightness in the ITB can increase friction it would seem logical to stretch the ITB and the muscles that attach to it - the Gluteus Maximus and Tensor Fascia Latae.
Discrepancies in leg length can lead to Runner's Knee. This is because there is more tension on the outer side of the knee in the longer leg. This tightens the ITB and causes increased friction. Leg length differences over 1cm should be corrected with a 'build up' insole on the shorter leg in order to restore symmetry.
A 'false' leg length discrepancy can be created if someone runs on a road that has a camber. The leg that is on the side closest to the gutter may experience increased tension in the ITB, which could lead to Runner's Knee. For this reason it is wise to run on a flat surface.
Weakness in the Gluteus Medius muscle has been linked with Runner's Knee in distance runners. The Gluteus Medius muscle is located at the top of the buttocks and is responsible for both raising the leg out to the side and turning the hip inwards. During running, it prevents the thigh from 'buckling' and rotating inwards. If there is a weakness and the knee 'buckles' then the tension in the ITB is increased. A strengthening programme to target the Gluteus Medius muscle can be very helpful for ITBFS, by helping to prevent the thigh from 'buckling in' during running.