Bicompartmental knee arthroplasty is proposed for those individuals with osteoarthritis limited to the medial and patellofemoral compartments of the knee. The bicompartmental knee arthroplasty procedure replaces only the diseased medial and patellofemoral compartments while sparing the lateral compartment and cruciate ligaments.

Investigational and Not Medically Necessary:

Bicompartmental knee arthroplasty is considered investigational and not medically necessary.

Bicompartmental knee arthroplasty has been proposed for those individuals with osteoarthritis limited to the medial and patellofemoral compartments. To estimate the utility of bicompartmental knee replacement Rolston et al (2007) conducted a study of 100 consecutive patients older than 40 years (average age 63.7; range: 40-88 years). The individuals were observed for arthritic compartmental involvement. Radiographic interpretation found that 73 of 100 patients had involvement of both the medial and patellofemoral compartments, but no lateral involvement. Identification of this subset of osteoarthritis patients supports the need for a treatment option between unicondylar knee arthroplasty and total knee replacement (TKR). A total of 95 patients were implanted by one surgeon beginning in October 2003 and followed for 33 months. Eighty-two of the 95 patients were discharged 2 days postoperatively. The average range of motion (ROM) for the group was 0° to 117°. Two weeks' postoperatively, most patients were able to walk with only a minimal limp and without the aid of assistive devices. Lateral joint line tenderness was not present. No participant required a blood transfusion. Although participants reported a high level of satisfaction following the procedure, this study was not randomized, controlled or blinded.

In a meta analysis, Callahan and colleagues (1995) studied unicompartmental and bicompartmental knee arthroplasties. Original studies were included if they enrolled 10 or more patients at the time of an initial knee arthroplasty and measured patient outcomes using a global knee rating scale. For the bicompartmental component, 18 studies met these criteria. The total number of enrolled patients was 884, with a mean enrollment of 44 patients and a mean follow-up period of 3.6 years. The mean patient age was 61 years; 79% were women, 31% had osteoarthritis, and 29% underwent a bilateral arthroplasty. The mean postoperative global rating scale score was 78.3. The overall complication rate was 30% and the revision rate was 7.2%. Patient outcomes were worse for bicompartmental arthroplasties than for other prosthetic designs; however, patients enrolled in these studies had more poorly functioning knees before surgery and actually had greater absolute improvements in global knee rating scores.

Currently, the published literature is insufficient and does not adequately demonstrate clinical efficacy and safety. Larger, well-designed studies comparing bicompartmental arthroplasty with total knee arthroplasty, the gold standard, are warranted.

A formal position is not taken by the American Academy of Orthopedic Surgeons (AAOS) with regard to bicompartmental knee replacement as a method of treatment for osteoarthritis of the knee in their 2008 clinical practice guideline (AAOS 2008).

Osteoarthritis (OA) of the knee is an increasingly common problem due to a more active society, prior knee injuries, an increase in the elderly population and a growing percentage of the population that is overweight. Osteoarthritis of the knee should be suspected when a patient presents with knee pain that has been longstanding, increases with activity, (e.g. weight bearing, stair climbing) and improves with rest. Onset of pain and dysfunction is often insidious. Deformity, fixed contracture, crepitance and effusion are common findings (AAOS 2003).

The knee has three compartments:

1. Patellofemoral compartment: behind the kneecap riding over the end of the femur "trochlea/sulcus" groove;
2. Medial compartment: the area of joint contact between the femur and tibia on the "inside" or medial aspect of the knee;
3. Lateral compartment: the area of joint contact between the femur and tibia on the "outside" or lateral aspect of the knee. 

OA can affect any or all of the compartments of the knee. Primary total knee replacement (TKR) is most commonly performed for knee joint failure caused by osteoarthritis. The success of primary TKR in most patients is strongly supported by more than 20 years of follow-up data. Bicompartmental research is focused on replacing the medial and patellofemoral compartments of the knee most often affected by OA, via minimally invasive surgery. Using this approach, it is expected that the lateral compartment, anterior cruciate ligament and posterior cruciate ligament will be preserved. These structures would provide increased stability during physical activity, such as walking, climbing stairs or simply standing up from a seated position.

Arthroplasty:  surgical replacement of all or part of a joint 

Femur: a bone of the leg situated between the pelvis and knee in humans 

Osteoarthritis: osteoarthritis (OA), which is also known as osteoarthrosis or degenerative joint disease (DJD), is a progressive disorder of the joints caused by gradual loss of cartilage. 

Range of motion (ROM): measurement of the extent to which a joint can go through all its normal spectrum of movements. 

Tibia: larger of the two bones of the lower leg and is the weight-bearing bone of the shin

The following codes for treatments and procedures applicable to this document are included below for informational purposes.  Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy.  Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.

When Services are Investigational and Not Medically Necessary:
When the code describes a procedure indicated in the Position Statement section as investigational and not medically necessary.

Peer Reviewed Publications: 

1. Callahan CM, Drake BG, Heck DA, Dittus RS. Patient outcomes following unicompartmental or bicompartmental knee arthroplasty. A meta-analysis. J Arthroplasty. 1995; 10(2):141-150.
2. Rolston L, Bresch J, Engh G, et al. Bicompartmental knee arthroplasty: a bone-sparing, ligament-sparing and minimally invasive alternative for active patients. Orthopedics. 2007; 30(8 Suppl):70-73.

Government Agency, Medical Society, and Other Authoritative Publications: 

1. American Academy of Orthopaedic Surgeons (AAOS). Treatment of osteoarthritis of the knee (non-arthroplasty). 2008.   Available at: http://www.aaos.org/research/guidelines/OAKguideline.pdf . Accessed on July 27, 2008.

1. Arthritis Foundation. Available at:  http://www.arthritis.org/. Accessed on July 27, 2009.

Arthroplasty
Bicompartmental