How does laxity after single radius total knee arthroplasty compare with the native knee?
Patients with total knee arthroplasties (TKAs) continue to report dissatisfaction in functional outcome. Stability is a major factor contributing to functionality of TKAs. Implants with single-radius (SR) femoral components are proposed to increase stability throughout the arc of flexion. Using computer navigation and loaded cadaveric legs, we characterized the "envelope of laxity" (EoL) offered by a SR cruciate retaining (CR)-TKA compared with that of the native knee through the arc of flexion in terms of anterior drawer, varus/valgus stress, and internal/external rotation. In both the native knee and the TKA laxity increased with increasing knee flexion. Laxities measured in the three planes of motion were generally comparable between the native knee and TKA from 0° to 110° of flexion. Our results indicate that the SR CR-TKA offers appropriate stability in the absence of soft tissue deficiency.
Institute of Cellular Medicine, Framlington Place Newcastle University, Newcastle upon Tyne, United Kingdom; Freeman Hospital, High Heaton, Newcastle upon Tyne, United Kingdom.
Nicola C
NC
Hunt
Kanishka M
KM
Ghosh
Alasdair P
AP
Blain
Kiron K
KK
Athwal
Steve P
SP
Rushton
Andrew A
AA
Amis
Lee M
LM
Longstaff
David J
DJ
Deehan
D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D001696:Biomechanical Phenomena; D002102:Cadaver; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology*; D007719:Knee Joint / Q000502:physiology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular / Q000502:physiology*; D025321:Surgery, Computer-Assisted; D016474:Weight-Bearing / Q000502:physiology
biomechanics; cruciate retaining; knee replacement; navigation; stability