Radiology Coding Alert

Question: A patient experienced a hard fall in their home and presented to the emergency department (ED) with severe right ankle pain. The radiologist captured three views of the patient’s right leg and diagnosed them with a displaced closed lateral and medial malleoli ankle fracture.

What ICD-10-CM codes do I need to assign to the report?

New Hampshire Subscriber

Answer: A bimalleolar ankle fracture involves two bones, such as the medial malleolus and the lateral malleolus. The medial malleolus consists of the medial, distal, end of the tibia, whereas the lateral malleolus includes the distal, outside, end of the fibula. A lateral and medial malleoli ankle fracture is an example of a bimalleolar fracture. In this example, you need to assign only one code — S82.841A (Displaced bimalleolar fracture of right lower leg, initial encounter for closed fracture) — to report the diagnosis.

Why? You’ll find Fracture, traumatic (abduction) (adduction) (separation) > bimalleolar in the ICD-10-CM index. This directs you to Fracture, ankle, bimalleolar, which, in turn, leads you to S82.84- (Bimalleolar fracture of lower leg).

To verify the ICD-10-CM code, turn to the tabular list in Chapter 19: Injury, Poisoning, and Certain Other Consequences of External Causes (S00-T88). In the tabular list, you’ll find S82.84- features a 6th character required icon. When you examine the available codes, you’ll notice the 6th character differentiates between displaced and nondisplaced fractures, allows you to choose between the right or left leg, or choose an unspecified lower leg if the information isn’t listed in the documentation. Furthermore, each of the six-character codes in the S82.84- family requires a 7th character.

Parent code S82.- (Fracture of lower leg, including ankle) features a 7^th character note that applies to all subsequent codes. The note instructs you to add the appropriate 7^th character to your code to indicate an open or closed fracture, type I, II, or III fracture; routine or delayed healing; nonunion or malnunion; initial encounter or subsequent encounter; or sequela. Since the patient presented to the ED for the displaced closed fracture, you’ll assign 7^th character A to report the diagnosis as an initial encounter for a closed fracture.

Remember: ICD-10-CM Official Guidelines, Section I.C.19.c, “Coding of Traumatic Fractures,” states, “A fracture not indicated whether displaced or not displaced should be coded to displaced.” In your question, you indicated the fracture was displaced, but if you receive a report where that information isn’t indicated, you’ll default to code the fracture as displaced according to the guideline.