KEN OKAZAKI
   Department   School of Medicine(Tokyo Women's Medical University Hospital), School of Medicine
   Position   Professor and Division head
Article types Original article
Language English
Peer review Peer reviewed
Title Gradual-radius femoral component with s-curve post-cam provides stable kinematics at mid-flexion after total knee arthroplasty.
Journal Formal name:Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association
Abbreviation:J Orthop Sci
ISSN code:14362023/09492658
Domestic / ForeginForegin
Volume, Issue, Page pp.Epub
Author and coauthor USHIO Tetsuro, HAMAI Satoshi, OKAZAKI Ken, GONDO Hirotaka, IKEBE Satoru, HIGAKI Hidehiko, NAKASHIMA Ysuharu
Publication date 2021/04
Summary BACKGROUND:Mid-flexion instability is the one of the reasons for patient dissatisfaction after total knee arthroplasty (TKA). The purposes of this study were to evaluate in vivo knee kinematics and clinical outcomes using a novel TKA design with a gradual femoral radius component and s-curve post-cam, which are intended to prevent the instability initiated by sudden reductions in the femoral radius observed with conventional components.METHODS:We used radiographic-based, image-matching techniques to analyze femorotibial anteroposterior translation, axial rotation, and anterior/posterior cam-post contact during two dynamic movements, squatting and stair climbing, in 20 knees that had undergone posterior-stabilized fixed-bearing TKA with an improved sagittal profiles of the femoral component and post-cam mechanism. We also evaluated patient-reported outcomes assessed by the 2011 Knee Society Score (KSS 2011).RESULTS:Squatting and stair climbing produced a similar trend in anteroposterior translation and a relatively small standard deviation at mid-flexion. Although the rotation angles varied widely during squatting and stair climbing, the femoral component was consistently externally rotated. Anterior/posterior cam-post contact during squatting and stair climbing were observed in 0/17 knees and 0/0 knees, respectively. The "Symptoms", "Satisfaction", and "Functional activities" subscales of the KSS 2011 were significantly (P < 0.05) improved postoperatively compared to preoperatively ("Symptoms", 10 to 21; "Satisfaction", 15 to 26; "Functional activities", 25 to 71).CONCLUSION:A gradual femoral radius component with an s-curve post-cam provided stable kinematics and favorable clinical results during squatting and stair climbing at 1 year after surgery.
DOI 10.1016/j.jos.2021.02.015
PMID 33933328