The iliotibial band friction syndrome (ITBFS) is a syndrome caused by inflammation deep to the iliotibial band (ITB), which is a band of tough fascia going from the hip to the knee along the outer aspect of the knee. The iliotibial band acts as a stabilizing structure, supporting the lateral part of the knee as the joint flexes and extends.

This condition is characterized by pain in the area over the lateral femoral condyle, more or less, following repetitive knee action. This condition is  most common in runners, cyclists and those who participate in similar sports. In fact, is known to be the most frequent among running injuries of the lateral or outer part of the knee.

ITBFS is the most common form of running injury affecting the lateral knee with an incidence of 1.6% and 12%, but makes up a fifth of injuries to the leg. It is also the most widespread overuse injury of the lower extremity among cyclists and in female athletes and in the rowers.

Causes

The outer part of the leg contains bursa, which is a water-filled sac between the bone and the tendon. When there is rubbing of the tendon, it can cause pain and swelling of the bursa, the tendon, or both. An injury or repeated bending of the knee can also lead to swelling of the tendon. Other common causes include:

• A compromised physical condition
• Tight ITB
• Bowed legs
• Alteration in the activity levels
• Not warming up before exercising

Symptoms

The patients usually experience pain over the lateral condyle of the femur or the outer side of the knee, and this area is tender on touch, especially just above the knee joint line. Other symptoms include difficulty and pain on climbing stairs, snapping of the ITB, poor muscle strength and difficulty in playing sports or taking part in such activities. The Ober test is done to measure the tightness of the band which is believed to correlate with the syndrome, though this is still controversial.

Pathology

The iliotibial band is a thickened part of the lateral fascia. When the knee performs a repetitive movement as in sports such as those mentioned above, the iliotibial band moves back and forth, rubbing over the lateral condyle, producing friction and then inflammation of the band. Some researchers think that such is not the case, and instead it is repeated tightening of the fascial band which compresses deeper connective tissue fibers against the underlying bone and irritates or damages them. Others have described a bursa below the ITB, excision of which relieved the symptoms. Both these views may be correct depending on the situation and the individual anatomy of the patient.

When the hip abductor muscles are weak, hip adduction may occur during walking, causing the ITB to undergo excessive strain. Other factors, such as the angle of knee flexion when the heel strikes the ground, or abnormal pronation of the foot, increased landing force and other biomechanical forces may be relevant to this injury.

Diagnosis and Treatment

The diagnosis of ITBFS is made by the history and examination findings, with imaging if required to rule out some other medical condition. The condition is treated by relieving the acute inflammation followed by a corrective treatment.

Acute inflammation may be treated with ice, oral non-steroidal anti-inflammatory drugs, or steroids, and the patient must desist from active movements at the knee. However, the healing may be delayed by such agents in many cases, though pain is alleviated.

Stretching of the ITB is frequently advocated but is doubtful in utility due to the correlation of the syndrome itself with a looser ITB. Other measures include the use of manual release techniques to release myofascial tightness in the band and neighboring structures.

Exercises to strengthen hip adductors is often advised as is improving the neuromuscular coordination. Many of these have been combined to construct a complex physical therapy and exercise program with stretches, massage, orthotic shoe inserts, and muscle training in multiple aspects.

Hard surface running and uphill jogging should be avoided until healing is complete.

If a cyst or bursa is also present, excision should be a necessary part of treatment.