Influence of Medial Collateral Ligament Release for Internal Rotation of Tibia in Posterior-Stabilized Total Knee Arthroplasty : A Cadaveric Study

Background: Previous studies suggested that changes in kinematics in total knee arthroplasty (TKA) affected satisfaction level. The aim of this cadaveric study was to evaluate the effect of medial collateral ligament (MCL) release by multiple needle puncture on knee rotational kinematics in posterior-stabilized TKA.
Methods: Six fresh, frozen cadaveric knees were included in this study. All TKA procedures were performed with an image-free navigation system using a 10-mm polyethylene insert. Tibial internal rotation was assessed to evaluate intraoperative knee kinematics. Multiple needle puncturing was performed 5,10, and 15 times for the hard portion of the MCL at 90° knee flexion. Kinematic analysis was performed after every 5 punctures. After performing 15 punctures, a 14-mm polyethylene insert was inserted, and kinematic analysis was performed.
Results: The tibial internal rotation angle at maximum knee flexion without multiple needle puncturing was significantly larger (9.42°) than that after 15 punctures (3°). Negative correlation (Pearson r.＝0.715, P < .001) between tibial internal rotation angle at maximum knee flexion and frequency of puncture was observed. The tibial internal rotation angle with a 14-mm insert was significantly larger (7.25°) compared with the angle after 15 punctures.
Conclusion: Tibial internal rotation during knee flexion was reduced by extensive MCL release using multiple needle puncturing and was recovered by increasing of medial tightness. From the point of view of knee kinematics, medial tightness should be allowed to maintain the internal rotation angle of the tibia during knee flexion which might lead to patient satisfaction.

内容要旨・審査要旨・論文本文の公開
本論文は, 著者Keizo Wadaの学位論文として提出され, 学位審査・授与の対象となっている。