title: Cartilage Degeneration and Alignment in Severe Varus Knee Osteoarthritis.
abstract: OBJECTIVE
  The aim of this study was to examine the relationship between cartilage, ligament, and meniscus degeneration and radiographic alignment in severe varus knee osteoarthritis in order to understand the development of varus knee osteoarthritis.
  
  
  METHODS
  Fifty-three patients (71 knees) with primary varus knee osteoarthritis and who underwent total knee arthroplasty were selected for this study. There were 6 men and 47 women, with 40 right knees and 31 left knees studied; their mean age at operation was 73.5 years. The ligament, meniscus, degeneration of joint cartilage, and radiographic alignments were examined visually.
  
  
  RESULTS
  The tibial plateau-tibial shaft angle was larger if the condition of the cartilage in the lateral femoral condyle was worse. The femorotibial angle and tibial plateau-tibial shaft angle were larger if the conditions of the lateral meniscus or the cartilage in the lateral tibial plateau were worse.
  
  
  CONCLUSIONS
  Based on the results of this study, progression of varus knee osteoarthritis may occur in the following manner: medial knee osteoarthritis starts in the central portion of the medial tibial plateau, and accompanied by medial meniscal extrusion and anterior cruciate ligament rupture, cartilage degeneration expands from the anterior to the posterior in the medial tibial plateau. Bone attrition occurs in the medial tibial plateau, and the femoro-tibial angle and tibial plateau-tibial shaft angle increase. Therefore, the lateral intercondylar eminence injures the cartilage of the lateral femoral condyle in the longitudinal fissure type. Thereafter, the cartilage degeneration expands in the whole of the knee joints.
authors.affiliation: Department of Orthopaedic Surgery, National Hospital Organization Kyoto Medical Center, Kyoto, Japan.
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Nakagawa
authors.affiliation: Department of Orthopaedic Surgery, National Hospital Organization Kyoto Medical Center, Kyoto, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Mukai
authors.affiliation: Department of Orthopaedic Surgery, National Hospital Organization Kyoto Medical Center, Kyoto, Japan.
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Yabumoto
authors.affiliation: Department of Orthopaedic Surgery, National Hospital Organization Kyoto Medical Center, Kyoto, Japan.
authors.forename: Eri
authors.initials: E
authors.lastname: Tarumi
authors.affiliation: Department of Orthopaedic Surgery, National Hospital Organization Kyoto Medical Center, Kyoto, Japan ; Department of Orthopaedic Surgery, Faculty of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakamura
keywords: cartilage degeneration; development; radiographic alignment; varus knee osteoarthritis