Kinematic analysis of a posterior cruciate retaining mobile-bearing total knee arthroplasty.

Using video fluoroscopy, 10 subjects having a mobile-bearing posterior cruciate-retaining total knee arthroplasty were analyzed to determine their in vivo kinematic patterns. Under weight-bearing conditions, while in extension, the average contact position was posterior to the mid-tibia sagittal plane with posterior translation of both condyles to 60 degrees of flexion, followed by anterior translation to 120 degrees of flexion. Under non-weight-bearing conditions, the average condylar contact positions were significantly more anterior from full extension to 90 degrees of knee flexion (P=.

In vivo determination of knee kinematics for subjects implanted with a unicompartmental arthroplasty.

Femorotibial contact positions for 20 subjects implanted with a unicompartmental knee arthroplasty (UKA) were analyzed using videofluoroscopy. Femorotibial contact paths were determined using a computer-automated model-fitting technique. Subjects having a medial UKA experienced on average -0.

In vivo determination of posterior femoral rollback for subjects having a NexGen posterior cruciate-retaining total knee arthroplasty.

This study determines the in vivo kinematics during a deep-knee bend activity for subjects implanted with a posterior cruciate-retaining total knee arthroplasty having asymmetric geometries. Of 20 subjects, 19 experienced posterior femoral rollback (PFR) of the lateral condyle (average -3.9 mm), and 13 subjects experienced PFR of the medial condyle (average -3.

In vivo kinematics for subjects with and without an anterior cruciate ligament.

The objective of the current study was to compare kinematic patterns of anterior cruciate retaining total knee arthroplasty and posterior stabilized total knee arthroplasty. Fifteen patients received an anterior cruciate retaining total knee arthroplasty and 15 received a posterior stabilized total knee arthroplasty. All total knee arthroplasties were clinically successful (Hospital for Special Surgery score > 90).

Correlation between condylar lift-off and femoral component alignment.

The current study analyzed subjects having a total knee arthroplasty to determine the incidence of condylar lift-off and correlate lift-off with the alignment of the femoral component with respect to the transepicondylar axis. Twenty-five subjects, implanted with a posterior stabilized total knee prosthesis, were asked to do weightbearing deep knee bends while under fluoroscopic surveillance. The two-dimensional fluoroscopic images were converted into three-dimensional images using a fully automated computer model-fitting technique.

Kinematic comparison of posterior cruciate sacrifice versus substitution in a mobile bearing total knee arthroplasty.

Interest in mobile bearing total knee arthroplasty (TKA) has increased significantly. The objective of this in vivo study was to analyze 2 different mobile bearing TKAs during gait and during a knee bend from 0 degrees to 90 degrees flexion. Femorotibial contact positions for 10 subjects, implanted by a single surgeon, were analyzed using videofluoroscopy.

In vivo comparison of femorotibial contact positions for press-fit posterior stabilized and posterior cruciate-retaining total knee arthroplasties.

The objective of this study was to determine the in vivo medial and lateral femorotibial condyle contact positions for 20 subjects having either a posterior cruciate-retaining (PCR) or posterior-stabilized (PS) total knee arthroplasty (TKA) while sitting and kneeling. The two-dimensional radiographic images were converted into three-dimensional images using an iterative computer model-fitting technique. Anteroposterior contact positions, axial rotation, and condylar lift-off were assessed for each subject.