June 10, 2004 |
By Stephanie Riesenman for Knee1
For years doctors have used cortisone shots to help relieve pain and inflammation in the knees of injured long-distance runners, and although the practice is common, there has been limited research to show the treatment actually works. But now a small trial involving South African runners has shown that a corticosteroid injection does reduce running pain after two weeks.
As many as 12% of running injuries are diagnosed as iliotibial band friction syndrome, or ITBFS. It is an inflammatory condition on the lateral side of the knee resulting from repetitive friction between the tendon and knee bone. The pain starts gradually and becomes most unbearable at a predictable distance or after running for a certain period of time. ITBFS is aggravated by repetitive knee flexion and is therefore also common in cyclists, down hill skiers, football players, and weight lifters.
Other causes of ITBFS have been suggested. Those causes include inflexibility of the tendon, hip abductor muscle weakness, abnormal limb alignment or rotation, the angle of the knee at which the foot strikes the floor while running, and even body type.
Research has shown that the bursa, or fluid layer surrounding the knee, becomes reddish brown and thickened at the site of pain when a runner develops ITBFS. If left untreated, this acute inflammatory response can become chronic, requiring surgery.
Treating ITBFS in the acute phase—during the first few weeks of the onset of pain—involves a variety of options including: ice, rest, reducing the intensity of workouts, running in a swimming pool, stretching, massage, oral non-steroidal anti-inflammatory drugs, and injections of cortisone.
In this study, conducted by Professor P. Gunter and Professor M. P. Schwellnus of the University of Cape Town Sports Science Institute of South Africa, a single injection of a corticosteroid at the site of knee pain was tested against a placebo to see if the cortisone would reduce ITBF syndrome in a population of 18 long-distance runners who completed the trial.
On the first day, all the athletes ran on a treadmill for 30 minutes or until they reached a pain measurement of 8 on a scale of 1 to 10—10 being the most painful. The participants were then randomly assigned to receive one injection of either 40 milligrams of methylprednisolone acetate or a placebo. The athletes were told not to run for 14 days and to ice their injured knees twice a day for 20 minutes. After 7 days and 14 days they were instructed to return to the lab for follow-up treadmill tests.
Between days 7 and 14, the runners injected with the methylprednisolone reported a significantly greater decrease in pain while running on a treadmill than the placebo group. But during the first seven days after injection the difference in pain scores between the placebo and cortisone groups was minimal.
The researchers concluded in their article, which was published in the June issue of the British Journal of Sports Medicine, that "local infiltration with corticosteroid decreases pain during running more so than placebo after 14 days in patients with ITBFS of recent onset."
While both groups experienced a reduction in pain overall, which the researchers attribute to 14 days icing of rest, injection with a corticosteroid as an early treatment of ITBFS provides a greater reduction of pain with no serious side-effects. But the researchers emphasized that injections should be delivered in conjunction with proper identification and correction of the underlying causes of ITBFS.
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