Orthopedic Coding Alert

Question: Encounter notes indicate that the orthopedist performed a knee arthrotomy. How should I report this procedure?

Tennessee Subscriber

Answer: You’ll need more information from the provider in order to report the exact knee arthrotomy code. And since there are six codes to choose from, you’ll need to know the difference between a few procedures that can occur along with the arthrotomy.

First, a look at the codes. Choose one of the following codes, depending on encounter specifics:

• 27330 (Arthrotomy, knee; with synovial biopsy only)
• 27331 (…  including joint exploration, biopsy, or removal of loose or foreign bodies)
• 27332 (Arthrotomy, with excision of semilunar cartilage (meniscectomy) knee; medial OR lateral)
• 27333 (… medial AND lateral)
• 27334 (Arthrotomy, with synovectomy, knee; anterior OR posterior)
• 27335 (… anterior AND posterior including popliteal area).

Key terms: If you aren’t in the know about all the terms in these descriptors, here’s a quick rundown of some of the most often confused terms:

• Arthrotomy: A procedure involving the incision of a joint.
• Synovial biopsy: Removing synovial fluid — thick fluid located in the synovial joints — for pathologic examination.
• Synovectomy: Excision of a synovium—the membrane that lines the joint cavity.
• Modifier alert: When reporting knee arthrotomies, be sure to use laterality modifiers LT (Left side) and RT (Right side) if your payer requires it.