AAOS Bulletin - April, 2005

Accurately code knee procedures

Address bundling issues to avoid questions of medical necessity

By Margie Scalley Vaught, CPC, CPC-H, CCS-P, ASC-OR and ; M. Bradford Henley, MD; William R. Beach, MD; Blair C. Filler, MD; and Bernard A. Pfeifer, MD

With more than half (52 percent) of AAOS fellows who responded to the 2004 Orthopaedic Census reporting adult knee as a primary focus area in their practices, it’s no wonder that there are so many coding questions on various knee procedures. This column will address accurately coding anterior cruciate ligament (ACL) reconstructions, chondroplasties, miniscectomies and meniscal repairs. The next issue will include the five new CPT codes for 2005 and minimally invasive/incision arthroplasty procedures.

Knee Anatomy

According to the Centers for Medicare and Medicaid Services (CMS), the knee has three separate, distinct compartments. The medial and lateral compartments comprise the femoral-tibial articulation; the third compartment is the patellofemoral compartment. The AAOS has endorsed this division for coding purposes.

The medial compartment contains the medial meniscus and the medial collateral ligament; the lateral compartment contains the lateral meniscus and lateral collateral ligament. The knee also contains the anterior and posterior cruciate ligaments.

When reporting services, the first determinations need to be: what type of procedure was performed, such as a repair, a reconstruction, a debridment, or an excision; and what technique was used: open or arthroscopic.

Take care when reporting ICD-9 codes in addition to the CPT codes for the surgical procedure. Knee problems can be acute or chronic, and there are specific ICD-9 codes relating to the type of condition. Correct coding requires that specific ICD-9 codes must be linked with the individual CPT codes for each knee procedure. Reporting the wrong ICD-9 code may mean you’ll have to answer questions later about the medical necessity of the procedure.

ACL reconstruction

The CPT code for an arthroscopic ACL reconstruction is 29888, “Arthroscopically aided anterior cruciate ligament repair/augmentation or reconstruction.” According to the AAOS Global Service Data Book (GSD), this code covers: minor synovial resection for visualization; notchoplasty; ACL stump removal; partial synovectomy and fat pad resection; intra-articular ligament reconstruction; harvesting and insertion of fascial, tendon or bone graft; diagnostic knee arthroscopy; internal fixation for graft; arthroscopic lysis of adhesions; manipulation of the knee, and additional or enlarging portals.

Excluded from an arthroscopic ACL reconstruction are: meniscectomy; meniscus repair; extra-articular augmentation, exclusive of screw tenodesis of the illiotibial band; arthroscopic chondroplasty, separate compartment; arthroscopic abrasionplasty; and arthroscopic removal of loose bodies.

Some orthopaedic surgeons have begun using thermal treatments to “tighten” a stretched ACL or to treat ACL laxity. CPT warns that it is incorrect to select a code that “merely approximates” the service being rendered and specifies that the anatomically specific unlisted code should be used. This means that code 29888 should not be used for thermal ACL procedures. The unlisted code 29999 should be used instead.

Because there is also no code for a revision (re-do) arthroscopic ACL reconstruction, this procedure could be reported with either code 29999 (unlisted) or code 29888-22. An open revision ACL could also be reported with the unlisted code (29999) or by appending modifier –22 to the original ACL code.

Harvesting and inserting the graft is included in code 29888, regardless of whether the graft is a patellar tendon or a hamstring tendon. If, however, the tendon is obtained from a distant site, such as the opposite leg, you may report the harvesting separately, using the most appropriate graft harvesting code (such as 2902X).

The rules for using the bone harvesting codes (20900, 20902) and the codes for harvesting other grafts are often misunderstood. These codes are only to be reported when the graft is harvested from a “separate” site through a separate skin or separate fascial incision, and “when the graft is not already listed as part of the basic procedure,” according to notes at the beginning of the Musculoskeletal System Section of the CPT Manual.

Some surgeons are now harvesting bone from the proximal tibia (e.g., from the bone tunnel) and grafting it to the patellar bone defect. This is considered a local bone graft, which is included in the base procedure, and should not be reported. Reporting this as a harvest and transplant would be considered unbundling.

Meniscus repair

Meniscus repair has two arthroscopic codes and one open code. Code 29882 is for “arthroscopy, knee, surgical; with meniscus repair (medial OR lateral).” Code 29883 is for “arthroscopy, knee, surgical; with meniscus repair (medial AND lateral).” The open code, 27403, is for “arthrotomy with meniscus repair, knee.”

Because the open code does not address the issue of compartments, there is some question about whether it covers both medial and lateral menisci or whether it can be reported twice. The CPT Manual refers coders to the arthroscopic code 29882, which seems to indicate that the open code 27403 is for medial OR lateral, and thus can be reported twice. However, carriers can have their own interpretations.

According to the AAOS Coding, Coverage and Reimbursement Committee, a surgeon who performs a medial and a lateral meniscus repair using open technique should report codes 27403 and 27403-59 (or -51, depending on carrier issues) to indicate two separate compartments were addressed. This is in line with both the relative value units and the recognized three compartments.

AAOS has requested that CMS clarify that listing a code for one compartment of the knee should not and will not affect coding for the other compartments. A change in the parenthetical notes reflecting this should appear in the 2006 edition of the CPT Manual.

According to the AAOS GSD, code 27403 includes: synovial biopsy; exploration of joint; resection of plica (partial or total); partial synovectomy; diagnostic arthroscopy; manipulation of the knee, and partial meniscectomy.

The AAOS GSD states that the arthrsocopic codes 29882 and 29883 include: plica/synovial resection; debridement/shaving of the meniscus; meniscal tissue removal (same meniscus); diagnostic arthroscopy; lavage and drainage; manipulation of the knee, and lysis of adhesions. Code 29882 does not include: meniscectomy of the other meniscus; removal of loose bodies (nonmeniscal) larger than 5 mm and/or through a separate incision.


CPT has two codes for synovectomy: 29875 for one compartment and 29876 for two or more compartments. However, this can be misleading.

Consider this example: A patient has a medial meniscectomy (29881) along with both medial and lateral synovectomies. Although this is technically a two-compartment synovectomy, the medial synovectomy is included in the code for the medial meniscectomy. Therefore, only a single compartment synovectomy (29875) can be reported.


The code for chondroplasty (29877) has caused much confusion, which is now aggravated by the addition of a Medicare HCPSC Level II code (G0289). Part of the confusion stems from the misreporting of the appropriate ICD-9 code. Chondromalacia of the patella is reported with ICD-9 code 717.7. However, chondromalacia of the medial or lateral knee should be reported with ICD-9 code 733.92.

The introduction of code G0289 for Medicare patients invalidates the use of CPT code 29877 when the chondroplasty is performed with another arthroscopic knee procedure. This does not mean that you cannot report a concomitant knee chondroplasty performed in a different compartment. However, it does mean that you must report the G0289 with the other procedures.

Here are some examples: you would report 29881 and G0289 for a Medicare patient who has a medial meniscectomy and a lateral chonroplasty. If just chondroplasties are performed in both the medial and lateral compartments, you would report code 29877. A medial meniscectomy with chondroplasties in both the lateral and patellofemoral compartments would be reported with 29881, G0289 and G0289-59. (Remember that modifiers can be carrier-driven issues.)

It can be a bit trickier for non-Medicare patients. Many third-party carriers are adopting the G code and requiring its use (instead of 29877) in reporting chondroplasties performed concurrent with other arthroscopic knee procedures. Carriers should understand that the G code can be reported more than once, provided each mention is for a separate compartment. However, code 29877 can be reported only once, regardless of how many compartments are affected.

Whether you use 29877 or G0289, you must have adequate documentation. In Medicare guidance published in the Nov. 7, 2002, Federal Register, “this add-on code is used only when the procedure performed is a substantive procedure needed to produce a significant improvement in the patient’s condition. Documentation supporting this should be reflected in the operative notes.”

Your documentation needs to describe what you found, how you performed the chondroplasty and whether it resolved the patient’s problem. A chondroplasty can be reported along with other arthroscopic procedures if it is supported by documentation.

Abrasion arthroplasty

AAOS guidelines permit reporting of abrasion arthroplasty if the documentation supports that debridement was performed down to “bleeding bone.” Abrasion arthroplasty is not limited by compartments and can be reported twice if performed in both the medial and lateral compartments (as 29879 and 29879-59 or -51, depending on carrier issues).

Many offices are reporting an abrasion arthroplasty (29879) when the documentation supports a chondroplasty (29877). Reporting a chondroplasty as an abrasion arthroplasty is considered “upcoding” and should not be done.

According to the AAOS GSD, code 29879 covers: synovial resection for visualization; removal of osteochondral and/or chondral bodies (attached); diagnostic arthroscopy; chondroplasty; lavage and drainage; lysis of adhesions, and manipulation of the knee. It does not include arthroscopic meniscectomy and/or repair or arthroscopic removal of loose bodies or foreign bodies 5 mm or greater and/or through a separate incision.

According to the August 2001 CPT Assistant, “When smoothing down the cartilage and/or drilling holes to create microfractures, code 29879 may be reported. Abrasion arthroplasty is usually performed to promote cartilage regeneration by creating access to blood and nutrients by smoothing down the cartilage and/or drilling holes to create microfractures. Code 29879 includes chondroplasty performed as part of the abrasion arthroplasty, so code 29877 should not be separately reported. If, however, chondroplasty is performed in a separate knee compartment, code 29877 may be reported separately. Modifier -59, Distinct Procedural Service, should be appended to indicate that a separate compartment was involved.”

Margie Scalley Vaught, CPC, CCS-P, CPC-H, ACS-OR, is an independent coding specialist in Ellensburg, Wash., a BONES member and a past member of the National Advisory Board, American Academy of Professional Coders. She can be reached at vaught@kvalley.com

M. Bradford Henley, MD, is chair of the AAOS Coding, Coverage and Reimbursement Committee; William R. Beach, MD; Blair C. Filler, MD; and Bernard A. Pfeifer, MD, are members of the committee.

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