THE INFLUENCE OF POSTERIOR CRUCIATE LIGAMENT TREATMENT IN MEDIAL PIVOT TOTAL KNEE ARTHROPLASTIES

Abstract

Medial pivot total knee arthroplasty is designed to permit posterior rolling and sliding of the lateral femoral condyle around a stable medial femoral condyle. The purpose of the current study was to analyze the weight-bearing kinematics of medial pivot TKA’s with three different treatments of the posterior cruciate ligament: PCL resected, PCL partially released and PCL retained, to determine if the PCL status had a significant effect on tibiofemoral translations or rotations in a medial pivot TKA design.

In vivo kinematics were determined for 17 clinically successful total knee arthroplasties during a stair-climbing activity using lateral fluoroscopy and shape matching techniques.

All three groups showed similar medial pivot motions. PCL retained knees showed significantly greater tibial internal rotation than PCL resected knees for flexion of 30° and greater. Rotation of the PCL released knees was midway between PCL resected and PCL retained knees

Regardless of PCL treatment, patients with medial pivot total knee arthroplasties had medial pivot motion patterns during stair climbing activities. This study showed a clear and intuitive trend in motions with PCL-treatment, such that knees with partially released PCL’s had kinematics midway between those where the PCL was either fully maintained or fully resected.