Orthopedic Coding Alert

Question: What is compartment syndrome, and how do I choose a diagnosis code for it? Notes indicate ‘nontraumatic compartment synd, lower ext.’

North Carolina Subscriber

Answer: Compartment syndrome is a reduction in circulation caused by traumatic or nontraumatic factors; it causes pain due to increased pressure due to swelling within a compartment.

The diagnosis codes for nontraumatic compartment syndrome are broken into four sets:

• M79.A1- (Nontraumatic compartment syndrome of upper extremity)
• M79.A2- (Nontraumatic compartment syndrome of lower extremity)
• M79.A3- (Nontraumatic compartment syndrome of abdomen)
• M79.A9- (Nontraumatic compartment syndrome of other sites).

So let’s say that encounter notes indicate that the provider diagnosed a patient with compartment syndrome of the left calf without any signs of trauma. You’d choose M79.A22 (Nontraumatic compartment syndrome of left lower extremity) for this patient.

Symptoms: There are a lot of symptoms that could add up to a compartment syndrome diagnosis. “Nontraumatic compartment syndrome of lower extremity may result in pain, tightness, tenderness, numbness or tingling sensation, muscle weakness, and restricted range of motion,” according to Codify.