The effect of femoral component rotation on the extensor retinaculum of the knee
Document Type
Article
Publication Date
1-1-2010
Abstract
Malrotation of the femoral component may cause patellofemoral complications after total knee replacement (TKR). We hypothesized that femoral component malrotation would cause excessive lengthening of the retinacula. Retinacular length changes were measured by threading fine sutures along them and attaching these to the patella and to displacement transducers. The knee post-TKR was flexed-extended while the quadriceps were tensed, then the measurements repeated after rotating the femoral component 5 degrees internally and then 5 degrees externally. Internal rotation shortened the medial patellofemoral ligament (MPFL) significantly from 100 degrees to 0 degrees extension. External rotation lengthened the MPFL significantly from 90 degrees to 0 degrees extension. The transverse fibers of the lateral retinaculum showed no significant differences. The MPFL attaches directly from bone to bone, so it was lengthened directly by movement of the trochlea and patella, whereas the deep transverse fibers of the lateral retinaculum attach to the mobile iliotibial tract, so they were not lengthened directly. (C)2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1136-1141, 2010
Keywords
Extensor retinaculum, total knee arthroplasty, femoral component rotation, patellar tracking, lateral release
Publication Title
Journal of Orthopaedic Research
Volume
28
Issue
9
Publisher
Wiley-Blackwell
Publisher Location
COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA