Effect of posterior design changes on postoperative flexion angle in cruciate retaining mobile-bearing total knee arthroplasty.
The Dual Bearing Knee (DBK) prosthesis is a new concept which has a mobile-bearing insert. In May 2001, the posterior femoral condyle design of the DBK was changed to become smaller and there was a posterior shift in the base of the insert dish (Hi-Flex). Between 1998 and 2004, 371 DBKs (112 Hi-Flex and 220 Standard) were performed by one surgical team. There was a significant difference in postoperative flexion angle between the Hi-Flex and Standard DBKs (117.0° and 111.3°; p = 0.001). The delta flexion angle in the Hi-Flex (-2.4°) was significantly increased compared with that in the Standard DBK (-9.6°) (p = 0.001). In the Hi-Flex DBK, the postoperative flexion angle (5.7°) and the delta flexion angle (7.2°) were significantly larger than for the Standard DBK (p < 0.001). These results suggest that the flexion is greater for a design with smaller posterior condyle prosthesis and with a posterior shift in the base of the insert dish in CR mobile-bearing TKA.
Orthopaedic Surgery, Hoshigaoka Koseinenkin Hospital, Hirakata, Osaka, Japan.
Shigeyoshi
S
Tsuji
Tetsuya
T
Tomita
Hideo
H
Hashimoto
Masakazu
M
Fujii
Hideki
H
Yoshikawa
Kazuomi
K
Sugamoto
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation* / Q000379:methods; D005260:Female; D005269:Femur / Q000601:surgery; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery*; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D016059:Range of Motion, Articular