Podiatry Coding & Billing Alert

Learn how similar procedures are reported differently.

An ankle arthroscopy operative report may describe excision of a talar dome lesion, microfracture, synovectomy, removal of impingement tissue, and retrieval of loose fragments. The same report may mention several surgical steps, multiple diagnoses, and numerous locations. That does not necessarily mean there are several separately reportable procedures.

Conversely, a report titled “ankle debridement” may contain enough detail to support a more specific osteochondral procedure. You have to look beyond the procedure heading and determine exactly what the surgeon treated.

Both problems are present in orthopedic coding audits. In one case, general debridement is added to a lesion excision because the surgeon worked in more than one area of the ankle. In another, the coder reports only limited or extensive debridement even though the operative description documents removal of an unstable osteochondral defect. These decisions can produce different reimbursement results, but reimbursement should never drive the code selection. The operative work, CPT^® instructions, and applicable payer policy have to support the claim.

Talar osteochondral lesions are a good example of why knowing the procedure matters as much as knowing the code. The operative report terminology can sound similar whether the surgeon is trimming a cartilage flap, excising an osteochondral defect, drilling subchondral bone, or repairing a fragment. Those are not interchangeable services.

In this three-part article series, Revenue Cycle Insider will show you how to approach ankle arthroscopy procedures and reports.

Begin With the Anatomy and the Procedure Performed

The talar dome forms the superior articular surface of the talus and articulates with the tibial plafond. Together with the surrounding ankle mortise, these structures make up the tibiotalar joint. An osteochondral lesion involves the articular cartilage and, to varying degrees, the bone beneath it. The surgeon may describe the defect as medial, lateral, or central on the talar dome and may identify it more precisely as anterior, middle, or posterior. These details are useful because they establish where the lesion was found and help the coder follow the treatment described in the body of the report.

The anterior gutter, medial and lateral gutters, and posterior region are common sites of additional arthroscopic work. The surgeon may resect synovial tissue to improve visualization, remove scar tissue and osteophytes to address impingement, or shave damaged cartilage along a different articular surface. That regional detail tells you what happened during surgery. It does not automatically establish a second procedure for coding purposes. The anterior gutter and the talar dome are different areas of the same tibiotalar joint, a point that becomes important when evaluating separate debridement reporting under Medicare.

The subtalar joint is a different matter. Located below the talus, it has a separate arthroscopic code family (29904-29907 [Arthroscopy, subtalar joint, surgical …]). If the surgeon enters and treats the subtalar joint in addition to the tibiotalar joint, the report should distinguish the joints, findings, portals, and work performed. Do not interpret a different location within the ankle as though it were a different joint, and do not assume that the word “posterior” establishes subtalar arthroscopy.

Another basic arthroscopy rule to keep in mind is that a surgical arthroscopy includes the diagnostic inspection of that same joint. The initial survey, probing of the lesion, and examination needed to plan the operative work do not create an additional diagnostic arthroscopy service. When the provider converts an arthroscopic procedure to an open procedure, the Medicare National Correct Coding Initiative (NCCI) generally directs reporting of the open procedure rather than the converted arthroscopy. An independent diagnostic arthroscopy followed by a separately indicated open procedure requires its own analysis of the facts and coding guidance.

Find out What Was Done to the Osteochondral Lesion

For a talar or tibial osteochondral defect, the central question is whether the surgeon excised the defect, repaired a fragment, or performed a different type of cartilage treatment. Code 29891 (Arthroscopy, ankle, surgical, excision of osteochondral defect of talus and/or tibia, including drilling of the defect) describes arthroscopic excision of an osteochondral defect of the talus and tibia and includes drilling when performed. The descriptor does not mean that drilling must occur in every case, but it does mean that you cannot report the drilling separately merely because the surgeon performed it after excision.

Example: An operative report describes an unstable 10 x 8 mm lesion along the medial talar dome. The surgeon lifts and removes delaminated cartilage, debrides nonviable tissue, prepares stable margins and the underlying base, and then uses a microfracture awl to penetrate the subchondral bone.

This is more than an isolated cartilage shave. The excision of the osteochondral defect supports consideration of 29891; the preparation of the defect and marrow stimulation are components of treating that lesion. Reporting another ankle code merely for microfracture would misrepresent how this procedure is captured.

The same report may use the word “chondroplasty” to describe smoothing the cartilage surrounding the lesion. That term should be read in context. When the surgeon trims unstable cartilage at the edge of the defect to prepare for excision or marrow stimulation, the work belongs to the lesion procedure. A separate chondral flap elsewhere in the joint is a different finding, but whether the associated debridement is separately reportable is a second question governed by bundling policy. You should first identify what the surgeon did, and only then decide how to report the complete operation.

Code 29892 (Arthroscopically aided repair of large osteochondritis dissecans lesion, talar dome fracture, or tibial plafond fracture, with or without internal fixation (includes arthroscopy)) addresses a different surgical approach: arthroscopically aided repair of a large osteochondritis dissecans lesion or a specified talar dome or tibial plafond fracture, with or without fixation.

Here, the fragment is retained and repaired rather than excised. The diagnosis alone does not determine the code. Two patients may both have an osteochondral lesion, yet one undergoes removal of the unstable defect with microfracture while the other undergoes reduction and fixation of a viable fragment. The surgeon’s operative technique determines which code family deserves consideration.

Drilling of a stable lesion with intact overlying cartilage requires more attention than a simple comparison of the words in the descriptor. The surgeon may use retrograde drilling without excising the articular surface.

A published orthopedic coding discussion from the Journal of the Pediatric Orthopaedic Society of North America identifies 29891 for arthroscopic drilling of a stable talar osteochondritis dissecans lesion. At the same time, the excision language in the code descriptor warrants careful review of current AMA guidance and the applicable payer’s instructions when the documentation describes drilling alone.

Expert tip: Avoid downgrading the work to general debridement or moving directly to an unlisted code solely because the surgeon didn’t remove any cartilage. Identify the exact technique and resolve any payer-specific questions before release.

Next month, Revenue Cycle Insider will look at how to report debridement with arthroscopic procedures.

Jennifer McNamara, CPC, CRC, CPMA, CDEO, CVBA,
COSC, CGSC, COPC, CEMA, Contributing Writer