Abstract
Introduction This study determined the relationship between the in vivo kinematics and joint laxity of mobile-bearing knees. Materials and methods Ten subjects who were judged clinically successful after a posterior-cruciate-ligament-retaining mobile-bearing total knee arthroplasty were analyzed under dynamic conditions using fluoroscopy, following a quantitative evaluation of coronal and sagittal laxity using Telos and KT-2000 arthrometers under static conditions. Results Under static conditions, the anteroposterior laxity averaged 10.3 mm at 30° of flexion, and 8.3 mm at 75°. Abduction and adduction at full extension averaged 3.7 and 4.4 mm, respectively. Under dynamic conditions, 7/10 subjects demonstrated posterior femoral rollback of their lateral condyle moving from full extension to maximum knee flexion, and 8/10 experienced normal axial rotation patterns during deep knee bend activity. Furthermore, 7/10 subjects exhibited screw-home motion. 4/10 subjects experienced greater than 1.0 mm of condylar liftoff. Conclusion We could not predict a consistent relationship between the laxity and kinematics. The activity of the muscles and ligamentous tension under dynamic conditions might have a much greater effect on the kinematics with currently used prosthetic designs than the laxity of ligamentous structures under static conditions.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
