2015 ISAKOS Biennial Congress ePoster #1446
Rotational Kinematic Analysis of a Cruciate Retaining and Posterior Stabilized Total Knee Arthroplasty
Tatsuhiko Kutsuna, MD, PhD, Toon, Ehime JAPAN
Kazunori Hino, MD, PhD, Toon, Ehime JAPAN
Yoshio Onishi, MD, Toon, Ehime JAPAN
Kunihiko Watamori, MD, Toon, Ehime JAPAN
Hiromasa Miura, MD, PhD, Prof., Toon, Ehime JAPAN
Department of Bone and Joint Surgery Ehime University Graduate School of Medicine, Toon, Ehime, JAPAN
FDA Status Cleared
Summary: Rotational kinematics patterns after total knee arthroplasty (TKA) had a variety. Both Cruciate Retaining and Posterior Stabilized-TKA had a tendency to remain preoperative kinematic patterns. Pre-operative knee extension angle affected to the change of rotational kinematics pattern in Posterior Stabilized -TKR.
Abstract:
Purpose:The purpose of this study was to analyze rotational kinematic patterns in knees treated with either cruciate-retaining (CR) or posterior-stabilized (PS) total knee arthroplasty (TKA), using an intra-operative navigation technique, and to clarify the factors that affect of the rotational kinematics and the difference rotational kinematics patterns between CR- and PS- TKA.
Methods
A total of 34 knees (34 patients) were included in this study, deformed valgus, sever flexion contractures, and highly unstable knees were excluded. These knees were allocated to CR or PS implants and underwent TKA with a computer navigation system. There was no significant difference in pre-operative parameters between CR- and PS-TKA group: age, femorotibial angle (FTA), and chondylar twist angle (CTA). The surgeon gently applied a manual range of motion from full extension to flexion. The angle of internal rotation in tibia to the functional plane of tibia and femur was measured automatically at max extension, 0, 30, 45, 60, 90 degrees, and max flexion throughout the passive knee motion.
Result: We categorized the post-operative rotational kinematics patterns to five types. Type A was increasing with the internal rotation angle in tibia with knee flexion. Type B was decreasing the internal rotation with knee flexion. Type C was decreasing the internal rotation from 0 to 45 or 60 degrees, Then graduated increasing until full flexion. Type D was the opposite type of type C. Type E was not able to categorize any pattern. The individual kinematic pattern was variable in pre- and post-operative knee motion. Both CR- and PS-TKA had a tendency to remain the preoperative kinematic pattern (CR-TKA 66% and PS-TKA 59%) by comparing the pre- and post-operative kinematic pattern. We analyzed factors (age, pre-operative FTA, CTA, pre-operative knee extension, and post-operative FTA) that affect the change of rotational kinematics patterns before and after TKA. In CR-TKR, there were not any factors that influence with the changes of kinematic pattern. In PS-TKR, pre-operative knee extension angle affected accompanied by significant difference in the change of rotational kinematics patterns.
Discussion
& Conclusion: Pre- and post-operative knee kinematics after TKA had a variety of rotational kinematics patterns. Both CR- and PS-TKA had a tendency to remain the preoperative kinematic pattern. Pre-operative knee extension angle affected to the change of rotational kinematics pattern in PS-TKR.