Sagittal Laxity After Posterior Cruciate Ligament-Retaining Mobile-Bearing Total Knee Arthroplasty

Julien Chouteau, MD,*yz Jean Luc Lerat, MD,* Rodolph Testa,*yBernard Moyen, MD,*y and Banks A. Scott, PhDz

The Journal of Arthroplasty Vol. 24 No. 5 2009

Abstract:

Posterior cruciate ligament stretching after posterior cruciate ligamentretaining (CR) total knee arthroplasty (TKA) can lead to an increase in sagittal laxity, knee dysfunction, or accelerated damage to the tibial bearing surface. We conducted a prospective study on 74 consecutive mobile-bearing CR TKA to determine if knee laxity changed with time or if knees with large initial laxity experienced greater increases in laxity. Patients were studied with radiographic posterior and anterior drawer examinations at 3 and 23 months. Model-based shape-matching techniques were used to measure TKA kinematics. We found a 1-mm increase in posterior drawer. Knees with large postoperative drawers did not exhibit increased laxity at last follow-up. The use of a mobile-bearing CR TKA did not significantly modify the midterm knee sagittal laxity.

* Service de chirurgie orthopédique, de traumatologie et de médecine du sport, Centre, Hospitalier Lyon Sud, Chemin du Grand Revoyer, 69495 Pierre Bénite, Cedex, France
† Université Lyon 1, F-69003; Institut National de Recherche sur les Transports et leur, Sécurité, Bron, F-69675, Laboratoire de Biomécanique et Mécanique des Chocs—UMR_T 9406, Faculté de médecine Lyon Sud, Oullins, France
‡ Orthopaedic Biomechanics Lab, Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida