title: Knee Extensor Strength and Gait Characteristics After Minimally Invasive Unicondylar Knee Arthroplasty vs Minimally Invasive Total Knee Arthroplasty: A Nonrandomized Controlled Trial.
abstract: In light of the existing lack of evidence, it was the aim of this study to compare gait characteristics and knee extensor strength after medial unicondylar knee arthroplasty (MUKA) with those after total knee arthroplasty (TKA), given the same standardized minimally invasive surgery (MIS) approach in both groups.
  
  
  
  Patients scheduled for MIS-MUKA or MIS-TKA as part of clinical routine were invited to participate. A posterior cruciate ligament-retaining total knee design was used for all MIS-TKA. A 3-dimensional gait analysis was performed preoperatively with a VICON system and at 8 weeks postoperative to determine temporospatial parameters, ground reaction forces, joint angles, and joint moments. At the same 2 times, isokinetic tests were performed to obtain peak values of knee extensor torque. A multivariate analysis of variance was conducted and included the main effects time (before and after surgery) and surgical group and the group-by-time interaction effect.
  
  
  
  Fifteen MIS-MUKA patients and 17 MIS-TKA patients were eligible for the final analysis. The groups showed no differences regarding age, body mass index, sex, side treated, or stage of osteoarthritis. We determined neither intergroup differences nor time × group interactions for peak knee extensor torque or any gait parameters (temporospatial, ground reaction forces, joint angles, and joint moments).
  
  
  
  It is concluded that MUKA is not superior to TKA with regard to knee extensor strength or 3-dimensional gait characteristics at 8 weeks after operation. As gait characteristics and knee extensor strength are only 2 of the various potential outcome parameters (knee scores, activity scores…) and quadriceps strength might take a longer time to recover, our findings should be interpreted with caution.
authors.affiliation: Department of Orthopaedic Surgery, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Matthias
authors.initials: M
authors.lastname: Braito
authors.affiliation: Department of Psychiatry and Psychotherapy, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Johannes M
authors.initials: JM
authors.lastname: Giesinger
authors.affiliation: Department of Orthopaedic Surgery, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Fischler
authors.affiliation: Institute for Sports Medicine, Alpine Medicine & Health Tourism, Innsbruck, Austria.
authors.forename: Arnold
authors.initials: A
authors.lastname: Koller
authors.affiliation: Department of Cardiology, Zurich University Hospital, Zürich, Switzerland.
authors.forename: David
authors.initials: D
authors.lastname: Niederseer
authors.affiliation: Department of Orthopaedic Surgery, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Liebensteiner
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D021621:Imaging, Three-Dimensional; D007719:Knee Joint / Q000503:physiopathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D053580:Muscle Strength / Q000502:physiology*; D016119:Posterior Cruciate Ligament / Q000601:surgery; D052097:Quadriceps Muscle / Q000503:physiopathology* / Q000601:surgery; D025321:Surgery, Computer-Assisted
keywords: gait analysis; minimally invasive surgery; partial knee arthroplasty; unicompartmental; unicondylar