Fistula, left knee

This code signifies the presence of an abnormal, pathological tract or opening involving the left knee joint. This tract typically connects the joint space to another structure, such as the skin (cutaneous fistula) or another internal organ, allowing for the passage of fluids. It often results from infection, trauma, or surgical complications.

Use this code when documentation clearly indicates a fistula originating from or involving the left knee. This diagnosis is supported by findings such as purulent drainage from the knee, imaging studies (e.g., fistulogram, MRI) demonstrating the tract, or direct visualization during surgery. It is appropriate for both acute and chronic presentations of a knee fistula.

• Always specify laterality (left knee) as indicated by the code.
• Look for documentation of the underlying cause of the fistula (e.g., infection, osteomyelitis, post-surgical complication) and code it as a secondary diagnosis if applicable.
• Differentiate from sinus tracts, which are blind-ended and do not connect two epithelialized surfaces.