Comparison of Alignment Correction Angles Between Fixed-Bearing and Mobile-Bearing UKA.
Good outcomes have been reported with both fixed-bearing and mobile-bearing unicompartmental knee arthroplasty (UKA). However, overcorrected alignment could induce the progression of arthritis on the non-arthroplasty side. Changes of limb alignment after UKA with both types of bearings (fixed bearing: 24 knees, mobile bearing: 28 knees) were investigated. The mean difference between the preoperative standing femoral-tibial angle (FTA) and postoperative standing FTA was significantly larger in mobile bearing UKA group. In fixed-bearing UKA, there must be some laxity in MCL tension so that a 2-mm tension gauge can be inserted. In mobile-bearing UKA, appropriate MCL tension is needed to prevent bearing dislocation. This difference in MCL tension may have caused the difference in the correction angle between the groups.
Department of Orthopaedics, Japanese Red Cross Kyoto Daiichi Hospital, Kyoto, Japan; Department of Orthopaedics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Atsuo
A
Inoue
Department of Orthopaedics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Yuji
Y
Arai
Department of Orthopaedics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Shuji
S
Nakagawa
Department of Orthopaedics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Hiroaki
H
Inoue
Department of Orthopaedics, Japanese Red Cross Kyoto Daiichi Hospital, Kyoto, Japan; Department of Orthopaedics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Shoichi
S
Yamazoe
Department of Orthopaedics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Toshikazu
T
Kubo
D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D018450:Disease Progression; D005260:Female; D005269:Femur / Q000601:surgery; D006801:Humans; D007717:Knee / Q000601:surgery; D007719:Knee Joint / Q000601:surgery*; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D010020:Osteonecrosis; D011184:Postoperative Period; D011474:Prosthesis Design; D016059:Range of Motion, Articular; D013314:Stress, Mechanical; D013977:Tibia / Q000601:surgery; D016896:Treatment Outcome
MCL tension; femoral-tibial angle; fixed-bearing; mechanical axis; mobile-bearing; unicompartmental knee arthroplasty