Runners Knee

The knee is a common site of pain and injuries in sportspersons because of its involvement in all kinds of sports. Many factors can cause knee pain, with runner’s knee or iliotibia

l band syndrome being one of the commonest.

Iliotibial band syndrome (ITBS) is an overuse injury characterised by pain on the outer side of the knee, caused by constant friction of the iliotibial band at the lower end of the thigh bone (near the outer aspect of the knee joint). It is common in long-distance runners, cyclists and other athletes, as well as military personnel.

The iliotibial band/tract is a thick band of fascia (a tissue that surrounds the muscles); it runs from the outside of the hip down to the knee. At its upper end it is attached to the Tensor Fasica Lata muscle in the front and the gluteus muscle at the back. From here it travels down on the outer side of the thigh, inserting at its lower end into the kneecap (patella) and the shin-bone (tibia).

Mechanism of injury:

The ITB is a very strong tissue that stabilises the knee in the extended as well as in the partially flexed position. When the knee is bent, the band shifts behind the femoral epicondyle (prominence at the lower end of the femur) and when the knee is extended, the band is again pulled forward in front of the epicondyle. A small fluid-filled sac (bursa) is interposed between the band and the femur to reduce friction; however repeated knee stretching and bending irritates the adjacent structures, leading to inflammation of the bursa, the band and the bone as well.

Cause:

Iliotibial band friction syndrome or ITBS is caused by functional overload. Factors that lead to ITBS include:

• sudden increase in activity level
• weak hip abductors (muscles that rotate the hip externally)
• poorly conditioned knee muscles (especially the front group, i.e., quadriceps)
• imbalance of power between the anterior and posterior hip muscles (both attach to the ITB at its upper end)
• a tight/short iliotibial band, as when in an adolescent the thigh grows faster than the band
• faulty biomechanics (overpronation, leg length discrepancy, etc.)
• sudden increase in duration or intensity of activity
• inadequate warm-up
• ill-fitting footwear.

Symptoms:

• Pain on the lateral side of the knee; may extend upwards along the length of the ITB or below the knee where it inserts into the shin-bone.
• Pain develops gradually, initially presenting as a stinging sensation on the lateral side of the knee during running or hiking, disappearing after cessation of the painful activity.
• With time the intensity increases, pain is particularly felt as the heel strikes the ground, the painful area becomes larger and pain may be initiated by walking or going up and down stairs, moreover it may persist longer
• Moving the hip outwards becomes difficult, bending or extending the knee causes pain
• A popping or snapping sound may be heard with knee movement.
• The outer side of the knee is tender and may swell in severe inflammation. The band itself thickens at the point where it rubs against the thigh bone.
• Pain along the upper end of the ITB is also possible. It is common in pregnant females and in the elderly.

Diagnosis:

Physical findings are enough to reach a diagnosis. X-rays may be taken to rule out any bone fractures or outgrowths. In severe cases, MRI is helpful in defining the extent of damage. It shows a thickening of the band (at the site of friction) along with fluid accumulation.

Treatment:

• Stop any painful activity and rest thoroughly,
• Use a pillow between the legs in bed at night to reduce the tension on the band.
• Apply ice packs and gentle compression to the area.
• Elevate the leg above heart level.
• Use insole devices to overcome problems with lower limb biomechanics such as overpronation.

A comprehensive rehabilitation program should be devised to:

• Improve mobility at the joint without causing pain
• Strengthen weak hip abductors and knee stabilisers
• Return to normal activity level

Stretching:

Start with mild stretching. Stop if it hurts. Hold the stretch for a few seconds, or more if it stays pain free. Repeat 3 to 4 times daily.

A warm band stretches better, use a heat pad or take a warm shower before stretching.

Strengthening:

Once movement is pain free, commence muscle strengthening exercises focusing on the:

• Hip abductors (Gluteus Medius, Tensor Fasciae Latae)
• Knee flexors (Hamstrings, calf muscles)
• Knee extensors (Quadriceps)

Sports massage improves circulation and helps to release excess tension in the band. It is recommended on a regular basis, the frequency depends on the person’s activity level.

Surgery for ITBS includes:

• Resecting a small piece of the ITB at the point where it creates the most tension
• Contouring the femoral epicondyle
• Removing the bursa

Surgery is not usually required as symptoms usually improve with proper rehabilitation.