Q&A: CPT code assignment for a trochleoplasty

Q: Which procedure code would you use for a surgical correction of the femoral trochlea (i.e., trochleoplasty)?

A: It depends what work is performed during the trochleoplasty. The procedure may require a simple debridement or a more extensive realignment of the patella.

The term “trochleoplasty” can be broken down into two parts: “trochlear,” which refers to the anatomic area known as the trochlear groove, and “-plasty” which refers to the molding, grafting, or formation of a specified part.

On the front of the knee, the patella (knee cap) glides up and down in the trochlear groove as the knee bends and straightens. However, if there is a problem with the shape of the groove or the patella, the patella may become unstable and dislocate. In such cases, a trochleoplasty may be performed to reshape the trochlear groove and stabilize the patella.

The patella may also be debrided, and a physician may perform tendon and muscle work. This is an open procedure performed under general anesthesia.

Per the CPT Manual, the work done on the trochlear groove is reported with CPT code 27418 (anterior tibial tubercleplasty [e.g., Maquet-type procedure]).

If work is also done on the patella to treat a subluxation or for re-alignment, one of the following codes would be reported for the reconstruction of a dislocating patella:

• 27420, reconstruction of a dislocating patella (e.g., Hauser type procedure)
• 27422, …performed by extensor realignment and/or muscle advancement or release (e.g., Campbell or Roux-Goldwaite type procedure)
• 27424, …performed with patellectomy

If an open procedure is performed for debridement or shaving of the articular cartilage and smoothing of the surface, an arthrotomy code may be appropriate. If the same procedure is performed via scope, debridement code 29877 (arthroscopy, knee, surgical; debridement/shaving of the articular cartilage [chondroplasty]) may be appropriate.

Select the most specific code based on documented indications for the procedure as well as the actual description (body of the note), which describes what was done.  

Editor’s note: Margie Scalley Vaught, CPC, CPC-H, CCS-P, MCS-P, ACS-EM, ACS-OR, is a healthcare consultant in Chehalis, Washington. She recently spoke on correct coding for spine surgeries at the 2018 Advanced Specialty Coding, Compliance & Reimbursement Symposium in Orlando.  

This answer was provided based on limited information. Be sure to review all documentation specific to your own individual scenario before determining appropriate code assignment.

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