title: Clinical Outcomes of Patients with Valgus Deformity Undergoing Minimally Invasive Total Knee Arthroplasty Through the Medial Approach.
abstract: OBJECTIVE
  The purpose of this study was to compare the clinical outcomes between patients with a valgus or varus deformity undergoing minimally invasive total knee arthroplasty through the medial approach.
  
  
  METHODS
  The patients were classified into 2 groups according to the preoperative femorotibial angle measured on an anteroposterior long leg roentgenogram. The valgus group comprised of 26 knees in 21 patients with a femorotibial angle <170° (163.5 ± 5.7), and the varus group comprised of 24 knees in 21 patients with a femorotibial angle >190° (195.9 ± 5.5). The following background variables were compared between the groups: age at the time of the operation, sex, causative disease, preoperative femoral mechanical-anatomical angle, and postoperative knee range of motion, Knee Society score, femorotibial angle, and implant position.
  
  
  RESULTS
  There were significant differences between the valgus and varus groups in the age (68.0 ± 6.9vs75.8 ± 6.2 years), percentage of males (23.8%vs0%), percentage with rheumatoid arthritis (61.9%vs4.8%), and preoperative femoral mechanical-anatomical angle (6.2 ± 1.0°vs7.4 ± 2.1°). Clinical outcome variables of postoperative femorotibial angle (173.1 ± 3.9°vs175.2 ± 1.6°) and α angle (96.6 ± 3.1°vs95.0 ± 1.9°) also differed.
  
  
  CONCLUSIONS
  It was assumed that over-valgus resection of the femur is a contributory factor to residual valgus alignment. However, knee range of motion and Knee Society score did not differ between the groups. We suggest that minimally invasive total knee arthroplasty through the medial approach is one of the treatment options for patients with valgus deformity.
authors.affiliation: Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine, Kanagawa, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Hamahashi
authors.affiliation: Department of Orthopaedic Surgery, Tokai University Oiso Hospital, Kanagawa, Japan.
authors.forename: Genya
authors.initials: G
authors.lastname: Mitani
authors.affiliation: Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine, Kanagawa, Japan; Department of Orthopaedic Surgery, Tokai University Oiso Hospital, Kanagawa, Japan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Takagaki
authors.affiliation: Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine, Kanagawa, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Serigano
authors.affiliation: Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine, Kanagawa, Japan; Department of Orthopaedic Surgery, Tokai University Oiso Hospital, Kanagawa, Japan.
authors.forename: Joji
authors.initials: J
authors.lastname: Mochida
authors.affiliation: Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine, Kanagawa, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Sato
authors.affiliation: Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine, Kanagawa, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Watanabe
keywords: Femoral Mechanical‒Anatomical Angle; Medial Approach; Minimally Invasive Total Knee Arthroplasty; Pie Crust Technique; Posterior-Stabilized Implant; Valgus Deformity