A893. KNEE DESIGN AND SURGICAL TECHNIQUE SIGNIFICANTLY REDUCE LATERAL RETINACULAR RELEASE RATES IN PRIMARY TOTAL KNEE ARTHROPLASTY

Abstract

Lateral retinacular release (LRR) may be necessary to balance the patellofemoral articulation in primary total knee arthroplasty (TKA). However, lateral retinacular release may be associated with an increased risk of patellar necrosis, loosening, perioperative bleeding, and pain.

Additionally, the need for lateral retinacular release may herald a more significant problem with implant positioning, rotation, and balance. The purpose of this study is to report the lateral retinacular release rate with a “patella friendly” femoral TKA design, and to identify if a less invasive approach is associated with reduced need for lateral retinacular release.

A retrospective review of our database identified 4667 primary TKA performed by two surgeons between October 2002 and January 2009. Beginning in 2002, a less invasive approach has been used in over 95% of primary TKA. Also beginning in 2002, the authors began using a new TKA design with a more swept back patellofemoral articulation (Vanguard Complete Knee System; Biomet). During the first two years of the study, the authors also used the Maxim Complete Knee System (Biomet). We previously reported a lateral retinacular release rate associated with the Maxim of 22%. There were 555 Maxim and 4112 Vanguard TKA performed. Lateral retinacular release with Maxim TKA was 12.8% (71/555), significantly less than that previously reported for the same implant design using a standard approach. Lateral retinacular release for Vanguard TKA was 1.8% (72/4112), significantly less than that with the Maxim TKA using either a standard or less invasive approach (p< 0.005).

Implant design, surgical technique, and a less invasive exposure combine to significantly reduce the need for lateral retinacular release in primary TKA.