title: The effectiveness of minimally invasive total knee arthroplasty to preserve quadriceps strength: a randomized controlled trial.
abstract: We performed a single-center, randomized, double-blind study to compare muscle strength in patients who had undergone primary total knee arthroplasty (TKA), performed using either a minimally invasive or a conventional surgical technique. We evaluated 30 knees in healthy age-matched subjects, 22 knees after conventional TKA (conventional group), and 23 knees after minimally invasive surgery TKA (MIS group). The Hospital for Special Surgery (HSS) score, Oxford knee score (OKS), and isokinetic (60º/s) muscle strength were evaluated the day before surgery and 3, 6, and 12 months after surgery. HSS and OKS improved significantly over time during follow-up (p<0.001), but there was no significant difference between the groups (p>0.05). The extensor peak torque (EPT) and flexor peak torque (FPT) improved significantly over time (p<0.001) and EPT was greater in the MIS group than in the conventional group during the follow-up period (p<0.05). There was no difference in FPT and the hamstring-to-quadriceps ratio between the groups. Although MIS patients had a significant deficit in extensor strength following TKA, compared with healthy controls, this approach offers a significant improvement in extensor muscle strength over conventional surgery. These results suggest that the MIS approach results in better outcomes with regard to maintaining extensor strength than the conventional surgical approach.
authors.affiliation: Department of Orthopedic Surgery, Seoul Paik Hospital, University of Inje College of Medicine, Seoul, Republic of Korea. boram107@hanmail.net
authors.forename: Jin Goo
authors.initials: JG
authors.lastname: Kim
authors.forename: Soo Won
authors.initials: SW
authors.lastname: Lee
authors.forename: Jeong Ku
authors.initials: JK
authors.lastname: Ha
authors.forename: Hong Joon
authors.initials: HJ
authors.lastname: Choi
authors.forename: Sang Jin
authors.initials: SJ
authors.lastname: Yang
authors.forename: Mi Young
authors.initials: MY
authors.lastname: Lee
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D007431:Intraoperative Complications / Q000517:prevention & control*; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery; D008297:Male; D019060:Minimally Invasive Surgical Procedures; D009119:Muscle Contraction / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology; D053581:Muscle Strength Dynamometer; D020370:Osteoarthritis, Knee / Q000503:physiopathology / Q000601:surgery; D052097:Quadriceps Muscle / Q000293:injuries* / Q000473:pathology / Q000502:physiology; D020127:Recovery of Function; D016896:Treatment Outcome