Orthopedic Coding Alert

Thermal anterior cruciate ligament (ACL) shrinkage is a new surgery that differs from traditional ACL reconstruction. Although less invasive than a reconstruction, the procedure requires significant work and expertise. But because thermal ACL shrinkage is a relative newcomer in orthopedics, no code exists to describe it accurately. As with so many techniques or services too new to have a CPT code, adequate documentation and comparative codes are the surest path to reimbursement.

An ACL Overview

ACL injuries are complete or partial tears to the ligament that provides stability in the knee. Although they can sometimes be treated conservatively, ACL injuries are often surgically corrected. The most common form of ACL repair is through arthroscopy (29888, arthroscopically aided anterior cruciate ligament repair/augmentation or reconstruction). During a traditional ACL repair for a complete tear to the ligament, a graft tendon is inserted in place of the damaged one.

Thermal ACL shrinkage is used to treat partial tears of the ligament that are due to stretching injuries. With arthroscopic guidance to visualize the operative site, a thermal probe is inserted into the knee, where it heats the damaged ligament to shrink and tighten it. The stretched ligament shrinks to its normal size, thus returning stability to the knee.

Therefore, when patients have elongated but otherwise intact ACLs, thermal shrinkage is a less invasive procedure that avoids the use of drill holes, large incisions and the harvesting of ligament graft from the hamstring muscle.

Traditional ACL reconstructions take about two hours, and the thermal shrinkages take about 45 minutes to one hour. Some orthopedic surgeons use 29888 to code for the procedure, but questions have arisen as to whether there is a more appropriate code. Carrier reactions to 29888 for thermal shrinkages have been mixed. Yet for coding, 29888 appears to be the closest match. The ACL is still reconstructed using the thermal probe, but the thermal shrinkage does not use an allograft or autograft as is traditionally done in an ACL reconstruction.

Coding Options

Of existing CPT codes, 29888 comes closest to describing the thermal shrinkage procedure, but only in the sense that both procedures repair a damaged ACL. According to the AAOS Complete Global Service Data for Orthopedic Surgery, 29888 includes harvesting and insertion of fascial, tendon or bone graft. Because thermal shrinkage does not include a graft component, the procedure takes half the time of a traditional repair. Therefore, if using 29888, modifier -52 (reduced services) should be appended with a note explaining how the procedure performed differs from 29888.

The downside to using the -52 modifier is that it may mean a substantial reduction from the original procedure. Rather than making the reduction before submitting the claim, coders should see what the carrier comes back with for reimbursement. If the payment seems much lower than what the practice deems a fair reimbursement for the surgery, they can appeal with further documentation describing the procedure and why they think the reimbursement should be increased.

Still, some coding experts feel that appending modifier -52 to 29888 is a logical coding decision, it is not the most accurate. ACL repair is very extensive and requires a great deal more work than thermal shrinkage, says Stanley M. Szelazek, CPC, a surgical review analyst with Kemper Insurance in Plantation, Fla. Although I dont downplay the work and skill involved in a thermal shrinkage, it does not meet the criteria for 29888 by any stretch of the imagination, and we would deny such a claim. Szelazek says an unlisted procedure code is the best choice until a new code is developed. Other coding experts agree that 29888-52 is best reserved for those carriers that will not reimburse for unlisted procedure codes.

Unlisted Procedure Code Choices

When using an unlisted procedure code for thermal ACL shrinkage, there are two codes to consider. Code 27599 (unlisted procedure, femur or knee) is used for virtually any knee procedure where there is no exact code match. Submitting an unlisted procedure code such as this means including an operative report and a KISS (keep it short and simple) letter describing the surgery. The letter should also explain the reimbursement amount requested on the claim.

The other unlisted procedure code, and likely the better choice, is 29909 (unlisted procedure, arthroscopy). Documentation methods for this code are the same as with 27599 submitting an operative report and KISS letter. But the unlisted arthroscopy code is more likely to impart to claims adjusters that this was something beyond a basic procedure. The letter you include should describe how the arthroscope is used as a guide for the thermal probe.

Code 29909 is the choice of Sheri Benton, CPC, a coding and reimbursement specialist for the department of orthopedics at the Cleveland Clinic Foundation in Cleveland, where thermal shrinkage procedures are done for shoulders and knees, but even this has its pitfalls. Benton says that virtually every claim for a thermal ACL shrinkage using 29909 is initially denied as being an experimental procedure. But we always appeal, she says. And we have about an 85 percent success rate with our appeals, especially if the ACL shrinkage is not done in combination with another procedure.

When submitting unlisted procedure codes, cite a comparative code, or one that is similar in both nature and amount of work to the unlisted procedure. This is the best place to employ 29888. When citing 29888 in the KISS letter (which should be written by the surgeon, not the coder), the physician can describe 29888 and how it compares and contrasts to the thermal ACL shrinkage. Because you will be asking for less payment than would accompany 29888, the letter should say, for example, It is my estimation that the thermal ACL shrinkage is ___ percent less work than 29888, therefore, I am requesting $___ in reimbursement.

Conversion Coding

Thermal shrinkage operative reports commonly note that an ACL is assessed for the suitability of thermal shrinkage. If attempted, and the ACL is of poor quality and does not shrink appropriately, or if it is unstable, the full arthroscopic repair with autograft or allograft will be completed. Because the success or failure of the thermal probe procedure is seen with the arthroscope, the surgeon knows whether he will need to carry out a graft in the same operative session.

When circumstances call for both the thermal attempt and the full reconstruction with graft, coders can attempt to obtain additional reimbursement by appending modifier -22 (unusual procedural services) to 29888. This is by no means a guarantee of payment because many payers may view thermal ACL shrinkage as an experimental procedure for which they will not reimburse. But, in the process of educating insurance companies as to which procedures are the most beneficial to their patients and in many cases the most cost-effective to the carrier it is worthwhile to illustrate the benefits of new procedures like thermal ACL shrinkage.

Benton also encourages her surgeons to encourage the AAOS and other professional societies to lobby the AMA to create new codes. With there being so many orthopedic procedures for which there is no CPT code, I really try to get our surgeons active in the lobbying process in order for us to move forward, Benton says. The payoff may not be immediate, but your efforts will pave the path for future reimbursements.