In vivo deep-flexion kinematics in patients with posterior-cruciate retaining and anterior-cruciate substituting total knee arthroplasty
Received 24 November 2008; accepted 23 September 2009. published online 23 October 2009.
Abstract
Background
Posterior-cruciate ligament retaining total knee arthroplasty designs have long been used with excellent clinical success, but often have shown kinematics and flexion performance that are significantly different from the natural knee. The purpose of this study was to compare deep-flexion knee kinematics in patients with two types of posterior-cruciate ligament retaining total knee arthroplasty.
Methods
One group received a traditional curved symmetric articular configuration, and one group received a design incorporating a lateral compartment which constrains the lateral condyle to the antero-posterior center of the tibial plateau in extension, but allows translation in flexion – roughly approximating the role of the anterior cruciate ligament. In vivo kinematics were analyzed using three-dimensional model registration and plain radiographs of kneeling and squatting activities in 20 knees in 18 patients.
Findings
Knees with the anterior cruciate ligament substituting design exhibited greater flexion, femoral antero-posterior translation and tibial internal rotation.
Interpretation
Geometric features intended to improve knee flexion, including greater antero-posterior stability, a more posterior tibial sulcus, and reshaped femoral condyles, do provide measurable and significant differences in deep-flexion knee kinematics.
cDepartment of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL, USA
dDepartment of Orthopaedics and Rehabilitation, University of Florida, Gainesville, FL, USA
Corresponding author. Address: University of Florida, Department of Mechanical and Aerospace Engineering, MAE-A Room 318, Gainesville, FL 32611-6250, USA.
ABSTRACT