Hiroshi Inui1, Shuji Taketomi2, Ryota Yamagami3, Kenichi Kono4, Kohei Kawaguchi5, Kentarou Takagi6, Tomofumi Kage7, Sakae Tanaka8. 1. Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan. Electronic address: hiroshi_inu0707@yahoo.co.jp. 2. Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan. Electronic address: taketomis-ort@h.u-tokyo.ac.jp. 3. Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan. Electronic address: yamagamir-ort@h.u-tokyo.ac.jp. 4. Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan. Electronic address: kounok-ort@h.u-tokyo.ac.jp. 5. Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan. Electronic address: kawaguchik-ort@h.u-tokyo.ac.jp. 6. Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan. Electronic address: takagik-ort@h.u-tokyo.ac.jp. 7. Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan. 8. Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan. Electronic address: tanakas-ort@h.u-tokyo.ac.jp.
Abstract
BACKGROUND: Of all the intraoperative kinematic parameters recorded using navigation systems, femorotibial rotational alignment is reportedly associated with the clinical outcomes of cruciate retaining and posterior stabilized (PS) total knee arthroplasty (TKA). However, to our knowledge, there are no reports on the relationship of newly designed bi-cruciate stabilized (BCS) TKA and intraoperative rotational kinematics. We aimed to clarify and compare the relationships between the intraoperative kinematics and clinical outcomes of BCS TKA and PS TKA. METHODS: We compared the intraoperative rotational kinematics and clinical outcomes at two years postoperatively of 56 BCS TKA patients and 55 PS TKA patients. Further, we evaluated the relationship between the femorotibial rotational kinematics and clinical outcomes. RESULTS: The maximum flexion angle and the pain subscale of the Knee injury and Osteoarthritis Outcome Score (KOOS) in BCS TKA were significantly better than those in PS TKA. The intraoperative kinematic data of BCS TKA showed "screw-home" movement, while that of PS TKA did not show this movement. The rotational angular differences between at maximum flexion angle and at 60° flexion of BCS TKA showed positive correlations with the improvement of KOOS pain, symptom, activity of daily living and sports subscales. The rotational angular differences between at maximum flexion angle and at 30° flexion in PS TKA showed positive correlations with the maximum flexion angle. CONCLUSION: Intraoperative femorotibial rotational kinematics and its influence on the clinical outcomes were different between BCS and PS TKA. BCS TKA showed more normal-like kinematics and better clinical results than PS TKA.
BACKGROUND: Of all the intraoperative kinematic parameters recorded using navigation systems, femorotibial rotational alignment is reportedly associated with the clinical outcomes of cruciate retaining and posterior stabilized (PS) total knee arthroplasty (TKA). However, to our knowledge, there are no reports on the relationship of newly designed bi-cruciate stabilized (BCS) TKA and intraoperative rotational kinematics. We aimed to clarify and compare the relationships between the intraoperative kinematics and clinical outcomes of BCS TKA and PS TKA. METHODS: We compared the intraoperative rotational kinematics and clinical outcomes at two years postoperatively of 56 BCS TKA patients and 55 PS TKA patients. Further, we evaluated the relationship between the femorotibial rotational kinematics and clinical outcomes. RESULTS: The maximum flexion angle and the pain subscale of the Knee injury and Osteoarthritis Outcome Score (KOOS) in BCS TKA were significantly better than those in PS TKA. The intraoperative kinematic data of BCS TKA showed "screw-home" movement, while that of PS TKA did not show this movement. The rotational angular differences between at maximum flexion angle and at 60° flexion of BCS TKA showed positive correlations with the improvement of KOOS pain, symptom, activity of daily living and sports subscales. The rotational angular differences between at maximum flexion angle and at 30° flexion in PS TKA showed positive correlations with the maximum flexion angle. CONCLUSION: Intraoperative femorotibial rotational kinematics and its influence on the clinical outcomes were different between BCS and PS TKA. BCS TKA showed more normal-like kinematics and better clinical results than PS TKA.