Osteophyte-related medial collateral ligament injury in asymptomatic osteoarthritis following minor trauma: a case report

A proximal deep medial collateral ligament (MCL) injury usually occurs in high-impact sports such as football or hockey. This injury is not common in low-energy trauma but the predisposing factor, in this case, was an osteophyte located next to the deep MCL ligament, which had likely caused degenerative changes to the ligament from chronic irritation, resulting in reduced strength of the ligament. CASE PRESENTATION: A 78-year-old Thai female presented with left knee pain 1 h after a low-energy trauma caused by a fall. The MRI showed deep MCL and medial meniscal root injuries, a nondisplaced lateral femoral condyle, and also revealed a large osteophyte near the midpart of the MCL, with a blunt persistent projection from the osteophyte pushing against the MCL where the injury was located. She was treated with a knee brace, a gait aid for walking, and analgesic pain control. Her symptoms gradually improved over the next few weeks. CLINICAL DISCUSSION: If an osteophyte touches a ligament, it can cause degenerative changes to the ligament from chronic irritation, resulting in reducing the strength of the ligament and may be causing some degree of degenerative changes and tightening of the MCL in its at-rest state, resulting in an increased chance of injury when it is required to resist a sudden external force, even from a minor trauma. CONCLUSION: When there is an osteophyte pushing against a ligament, there is an increased chance of ligament injury when even a minor trauma stresses that ligament.