Part B Insider (Multispecialty) Coding Alert

Original surgeon may have missed posterolateral corner instability

There's no such thing as a simple anterior cruciate ligament revision. But you just never know how complicated an arthroscopy with ACL revision can become.

As techniques for ACL reconstruction have become more refined in recent years, surgeons have also discovered that instability in the posterolateral corner of the knee often comes with ACL tears. The kinds of injuries that shred someone's ACL often cause problems in the PLC as well.

Chances are, the surgeon who performed the original ACL reconstruction or repair missed this problem, but your surgeon is more likely to come across it in the revision process.

But an injury to the posterolateral corner can require open surgical reconstructions to a number of structures, including the popliteus tendon, arcuate ligament, lateral collateral ligament, biceps tendon and iliotibial band, says Heidi Stout, coding and reimbursement manager of University Orthopedic Associates in New Brunswick, N.J.

If a patient requires a surgical repair of a PLC injury associated with an acute knee dislocation, you can code this extra work using either CPT 27557 (Open treatment of knee dislocation ...; with primary ligamentous repair) or 27558 (... with augmentation/dislocation), Stout says.

But if the patient has chronic instability of the PLC, you can code it using either 27427 (Liga-mentous reconstruction [augmentation], knee; extra-articular), 27428 (... intra-articular [open]) or 27429 (... intra-articular [open] and extra-articular). Which code you use depends on the details of the operative report, Stout says. And these are just examples; you may have to use other codes to convey the details of what happened.

Another possibility for coding a PLC repair in addition to an ACL revision is to use 27405 (Repair, primary, torn ligament and/or capsule, knee;collateral) for the PLC repair, alongside 29888 for the ACL revision, says Mary Brown, orthopedic coding specialist at OrthoWest in Omaha, Neb. But if the surgeon somehow managed to repair the PLC arthroscopically, then you can just use 29999 (Unlisted procedure, arthroscopy).

"For all of these complex procedures, I also include the operative report and a letter explaining why these codes were used," Brown says.

Also, you can report the removal of any hardware separately using 20680 (Removal of implant; deep [e.g. buried wire, pin, screw, metal band, nail, rod, or plate]). But many payers won't pay separately for 20680, Brown says. They consider it included in 29888.