Orthopedic Coding Alert

"Total knee replacement presents a double challenge for codersmodifiers must be used correctly and the global surgical package must be understood.

The scenario: An obese 45-year-old woman suffering from end stage (degenerative) arthritis endured as much pain and loss of mobility in her knees as she could tolerate. Despite her relatively young age and the difficulty she would have during rehabilitation because of her weight, she and her orthopedic surgeon (OS) agreed during an office visit that she should have a total knee replacement (TKR) in each knee.

To provide the best chance of successful rehabilitation, the OS replaces only the right knee. After the woman regains function in that knee, the OS will replace the left knee.

The diagnosis for the womans condition is degenerative arthritis, 715.96 (osteoarthrosis; lower leg). Modifier -57 (decision for surgery) should be attached to the appropriate level of established patient evaluation and management (E/M) service (99211-99215) that resulted in the initial decision to perform surgery. If the womans obesity is of unspecified origin (278.00) and the OS records the condition as contributing to or exacerbating her knee problems, it could be listed as a secondary diagnosis.

The coding: Pat Strubberg, CPC, processing team manager at Physician Data Management in St. Louis, shares details about coding for TKR and the potential pitfalls.

A total joint replacement is sometimes called an arthroplasty, she explains. Arthroplasty is defined as reconstructive surgery of a joint to restore motion. But not all arthroplasty involves all the components required to make it a TKR in the lexicon of CPT. A knee replacement can be a total knee or a single component, says Strubberg. The components are medial and lateral. It is important to read the operative report to ensure that it is truly a total knee.

The correct code for a total knee replacement is 27447 (arthroplasty, knee, condyle and plateau; medial AND lateral compartments with or without patella resurfacing [total knee replacement]). If only a medial or lateral component is the target of the replacement (unicondylar knee replacement), use 27446 (arthroplasty, knee, condyle and plateau; medial OR lateral compartment).

Special Coding Considerations

Modifiers: Strubberg reminds, It is appropriate to use modifier -RT (right side) or -LT (left side) when coding 27447. If the knee replacement is bilateral, use modifier -50 (bilateral procedure) and double the normal fee. Many carriers will reimburse only the bilateral procedure at 150 percent of the single one.

Global period: The global surgery package is 90 days and it includes synovectomy, removal of loose bodies, debridement of the knee, meniscectomy, lateral retinacular release, ligament or capsular release or reconstruction, manipulation of knee and arthrotomy, explains Strubberg. In short, do not try to code separately for any of those procedures or it will constitute unbundling. Note: See below for a refresher on the global period.

Tricky combinations: Cindy Parman, CPC, CPC-H, principal of Coding Strategies in Dallas, Ga., a company that does billing for medical practices, says, Many times a patient goes to a VA (Veterans Administration) facility for the TKR and after having the replacement, wants to be seen by an orthopedist (in private practice).

Because the patient is arriving at the orthopedist after surgery and the orthopedist takes over care during the global period, modifier -55 (postoperative management only) would be attached to 27447 by the orthopedist. The OS at the VA hospital would be required to submit 27447 with modifier -54 (surgical care only).

An orthopedist in Florida who sees a winter visitor who had a TKR in New York just before traveling often does not know whether the OS in New York used a modifier. E/M codes can be used from the beginning for follow-up care, but the OS is obligated to use modifier -54 when he or she knows it applies. Even if the OS does not know, an insurance company may follow a payment trail later and ask the OS to pay back a portion of the money allotted for a global package.

When the TKR fails: There are separate CPT codes for revision surgery. If the failure of the TKR requires a revision to only one component, use 27486 (revision of total knee arthroplasty, with or without allograft; one component). For the entire knee, use 27487 (revision of knee arthroplasty, with or without allograft; femoral and entire tibial component).

If the knee fails during the global period (for 27447), use modifier -78 (return to the operating room for a related procedure during the postoperative period) with 27487, says Catherine Brink, CMM, CPC, president of HealthCare Resource Management, Spring Lake, N.J. And always send a copy of the operative note.

The ICD code for the revision depends on the reason for the failure. For example, it might be a loose femoral component (996.4, mechanical complication of internal orthopedic device, implant, and graft) or infection (996.66, infection and inflammatory reaction due to internal joint prosthesis). The correct V code to reflect the patients health status (V43.65, replaced knee joint) should be recorded."