IT Band Syndrome Secondary to Osteogenic Cysts of the Proximal Tibia: A Rare Case Report

Pain on the outside of the knee is a common complaint, often blamed on overuse. When the thick band of tissue running down the side of the leg, known as the iliotibial band, rubs against the bone, it can become inflamed and painful. This condition, called iliotibial band syndrome, is usually treated as a simple injury caused by too much running or climbing. Doctors typically look for signs of wear and tear or inflammation in the soft tissue itself. However, sometimes the source of the pain is not the tissue rubbing, but something underneath it that is making the rubbing worse. In rare cases, a hidden problem inside the bone can change the shape of the surface, turning a normal movement into a constant, irritating friction.

A team of surgeons at the All India Institute of Medical Sciences in Jodhpur, India, recently documented one such rare instance. They treated a forty-five-year-old woman who had been suffering from worsening pain on the outer side of her left knee for several months. Her pain grew worse when she walked, stood for long periods, or climbed stairs. She had not injured her knee, and she had no fever or other signs of illness. When the doctors examined her, they found a specific spot on the upper part of her shinbone that was tender to the touch. The knee could move fully, but the very end of the movement caused sharp pain.

Standard X-rays and magnetic resonance imaging scans revealed the true cause. Instead of a simple soft-tissue injury, the images showed a small, well-defined hole in the outer layer of the bone near the knee. This hole, measuring 2.2 by 1.5 centimeters, was an osteogenic cyst. While the scans showed the cyst's location and size, a fluoroscopy-guided assessment during the procedure confirmed that the cystic material had a bony, cement-like consistency. The scans also showed that the bone around this cyst was slightly swollen and that the soft tissue directly above it was reacting to the irritation. The cyst had altered the smooth surface of the bone, creating a rough spot that the iliotibial band rubbed against with every step.

To confirm the diagnosis and treat the problem, the surgeons performed an operation. They made an incision on the side of the knee and found the cyst inside the bone. Directly above it, the iliotibial band had become thick and fibrous, a clear sign that it had been rubbing against the cyst for a long time. The team carefully removed the cyst and the thickened section of the band. A microscope examination of the removed tissue confirmed that the cyst contained bony material and that the band showed signs of chronic irritation and scarring.

The patient recovered quickly and was able to return to her normal activities. At her follow-up visit, she reported that the pain had completely disappeared and had not returned. This case highlights that while iliotibial band syndrome is often a simple overuse injury, it can sometimes be a secondary effect of a hidden bone cyst. When a patient has persistent pain on the outside of the knee accompanied by a visible spot on the bone in imaging tests, doctors should consider that a cyst might be the root cause. Removing both the cyst and the irritated tissue can provide a complete cure, whereas treating only the symptoms might leave the underlying problem unresolved.