DESCRIPTION
The unicondylar interpositional spacer has been proposed for knee joint repair due to conditions such as early-stage osteoarthritis. The device is a U-shaped metallic shim that does not require any bone resection or mechanical fixation (e.g., cement, screws) due to being self-centering in the knee. Following arthroscopic debridement and resection of the meniscus, the device is inserted into the joint space above the affected tibial plateau, resting within the boundaries of the resected meniscus. The femur then articulates against the curved surface of the device.
Examples of U. S. Food and Drug Administration approved devices used for this procedure include the UniSpacer® Knee System, Oti Unicondular Interpositional Spacer, Orthoglide Medical Knee Implant and the Knee Interpositional Mini-Repair System.
POLICY
Unicondylar interpositional spacer for the treatment of osteoarthritis is considered investigational.
See also:
ADDITIONAL INFORMATION
Well-designed studies in peer-reviewed journals regarding this technology are lacking. Comparative studies of this technology to current medical (i. e., analgesics, antiinflammatory medications) or surgical (i.e., osteotomy, total joint replacement) treatments are not available. Long-term studies are not yet available to establish the safety and efficacy of this technology, especially whether the technology may postpone or prevent the need for total knee joint replacement.
SOURCES
BlueCross BlueShield Association. Medical Policy Reference Manual. (5:2008). Unicondylar interpositional spacer as a treatment of unicompartmental arthritis of the knee (7.01.88). Retrieved February 6, 2009 from BlueWeb.
Scott, R. D. UniSpacer: (2003). Insufficient data to support its widespread use. Clinical Orthopaedics and Related Research, 416, 164-6.
Sisto, D. J., & Mitchell, I. L. (2005). UniSpacer arthroplasty of the knee. The Journal of Bone and Joint Surgery, 87 (8), 1706-1711.
U. S. Food and Drug Administration. (2003, December). Center for Devices and Radiological Health. 501(k) notification K033242. Retrieved July 1, 2009 from http://www.accessdata.fda.gov/cdrh_docs/pdf3/k033242.pdf.
ORIGINAL EFFECTIVE DATE: 4/12/2007
MOST RECENT REVIEW DATE: 10/9/2008
ID_BT
Policies included in the Medical Policy Manual are not intended to certify coverage availability. They are medical determinations about a particular technology, service, drug, etc. While a policy or technology may be medically necessary, it could be excluded in a member's benefit plan. Please check with the appropriate claims department to determine if the service in question is a covered service under a particular benefit plan. Use of the Medical Policy Manual is not intended to replace independent medical judgment for treatment of individuals. The content on this Web site is not intended to be a substitute for professional medical advice in any way. Always seek the advice of your physician or other qualified health care provider if you have questions regarding a medical condition or treatment.
This document has been classified as public information.