Sprain of lateral collateral ligament of knee

This code signifies an injury to the lateral collateral ligament (LCL) of the knee, characterized by stretching or tearing of its fibers. This ligament is located on the outer side of the knee joint and helps stabilize it against varus stress. The injury can range from a mild stretch to a complete rupture.

Use this code for documented diagnoses of LCL sprains resulting from trauma, such as a direct blow to the inside of the knee or a hyperextension injury. Supporting documentation should include a physical examination noting tenderness, swelling, and instability on varus stress testing, often accompanied by imaging findings (e.g., MRI) confirming LCL involvement.

• Differentiate from medial collateral ligament (MCL) sprains, which are coded separately.
• Ensure documentation specifies "lateral" to avoid confusion with other knee ligament injuries.
• Consider sequencing with external cause codes (E-codes) if the injury resulted from an accident.