Coding Corner August 2009

Daniel J Nagle MD

First CMC arthroplasty techniques and relative values continue to evolve.  I thought this would be a good time to provide you with an update on first CMC arthroplasty coding.

Arthroscopically assisted interposition arthroplasty

Arthroscopically assisted interposition arthroplasty is becoming popular.  While this procedure certainly qualifies as an “interposition arthroplasty,” 25447 Arthroplasty, interposition, intercarpal or carpometacarpal joints, does not accurately describe the work associated with an arthroscopically assisted first CMC arthroplasty. The AMA Relative Value Update Committee database service descriptor for 25447 clearly describes a standard open approach and therefore it would not be appropriate to use that code for this procedure.

One way of reporting arthroscopically assisted first CMC interposition arthroplasty would be to use the wrist arthroscopy code 29846 Arthroscopy, wrist, surgical; excision and/or repair of triangular fibrocartilage and/or joint debridement. The use of this code is perfectly rationale given that the first CMC joint is a part of the wrist. Clearly a debridement of the joint is performed. The setup for both standard wrist arthroscopy and first CMC arthroscopy are similar.  The postoperative regimen includes immobilization just as in the case of a TFCC repair. The work associated with the insertion of the arthroplasty material would not be accounted for but this represents a small portion of the total physician work associated with this procedure. (There are currently no codes to describe the work associated with the preparation and insertion of off-the-shelf interposition materials.)

If, during an arthroscopically assisted first CMC arthroplasty a free autologous graft is harvested from a different site and is inserted in the arthroplasty site, the work associated with the harvesting of the graft should be coded separately with 20924 Tendon graft, from a distance (e.g., palmaris, toe extensor, plantaris) with a -51 modifier added to 20924. 

Hematoma Arthroplasty

Dr. Roy Meals and others have popularized  “hematoma arthroplasty.” This procedure does not fulfill the definition of an interposition arthroplasty since nothing is interposed in the arthroplasty site. This procedure is in fact a carpectomy and therefore, the correct coding for this procedure would be 25210 Carpectomy; one bone.

First CMC excisional arthroplasty

The traditional first CMC excisional arthroplasty that includes partial or complete excision of the trapezium, with or without resection of some of the base of the first metacarpal and insertion of either a locally harvested graft or a graft harvested through a separate incision should be coded with 25447 Arthroplasty, interposition, intercarpal or carpometacarpal joints. If a tendon graft is harvested from a site other than the operative wound 20924 Tendon graft, from a distance (e.g., palmaris, toe extensor, plantaris) should be reported with a -51 modifier added to 20924.

Suspension arthroplasty

The suspension arthroplasty described by Dr. Richard Burton in the early 1980s is similar to the procedure described above except that in addition to the excision of the trapezium and base of the first metacarpal, a tendon transfer is performed to stabilize the first metacarpal (26480 Transfer or transplant of tendon, carpometacarpal area or dorsum of hand; without free graft, each tendon.) The coding for this procedure has not significantly changed but the relationship between the tendon transfer code that is used in addition to 25447 needs to be updated in view of the change in the relative value of 26480. The current total relative value (RVU) for 26480 is 18.8 and the total RVU for 25447 is 20.81. The multiple procedure rules dictate that the primary code is that code with the highest RVU, which in this situation would be 25447 with a total RVU of 20.81. Therefore, the correct coding combination for a “Burton suspension arthroplasty” is as follows:

25447 Arthroplasty, interposition, intercarpal or carpometacarpal joints
26480-51 Transfer or transplant of tendon, carpometacarpal area or dorsum of   hand; without free graft, each tendon

There are no Correct Coding Initiative (CCI) edits that preclude this combination.

First MCP stabilization

The following codes can be used in addition to the above listed codes to describe the work associated with the stabilization of a hyperextensible first metacarpophalangeal joint. The - 51 modifier should be appended to these codes when they are used with other procedures with higher RVUs.

 26516 Capsulodesis, metacarpophalangeal joint; single digit
 26850 Arthrodesis, metacarpophalangeal joint, with or without internal fixation

Summary

I will endeavor to keep you updated on the rapid changes occurring in health care reform.

I wish you all a pleasant summer.  

Dan