title: Alignment in total knee arthroplasty following failed high tibial osteotomy.
abstract: In total knee arthroplasty (TKA) following failed high tibial osteotomy, the mechanical axis does not intersect the center of the tibial component if the tibia has been resected perpendicular to the anatomical axis. Therefore, tibial resection referencing the predicted postoperative mechanical axis instead of the tibial shaft axis is advocated. To obtain the optimal tibial resection, characteristics of the tibial proximal deformity were measured radiographically and predicted postoperative lower limb alignment was calculated using full-length, weight-bearing, lower limb anteroposterior radiographs. Two finite element analysis models also were examined. The proximal tibia was resected perpendicular to the tibial shaft axis in model 1, and perpendicular to the predicted postoperative tibial mechanical axis in model 2. When the proximal tibia was resected perpendicular to the tibial shaft axis, the predicted lower limb mechanical axis was significantly shifted medially to the center of the tibial joint surface. The results of the finite element analysis reflected the medial shift of the lower limb mechanical axis in model 1, where stresses were increased in the medial tibial compartment. Tibial resection referencing the predicted postoperative tibial mechanical axis, instead of the tibial shaft axis, should be performed, especially in cases with a deformed tibia.
authors.affiliation: Dept of Orthopedic Surgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Kawano
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Miura
authors.forename: Ryuji
authors.initials: R
authors.lastname: Nagamine
authors.forename: Ken
authors.initials: K
authors.lastname: Urabe
authors.forename: Shuichi
authors.initials: S
authors.lastname: Matsuda
authors.forename: Taro
authors.initials: T
authors.lastname: Mawatari
authors.forename: Takaaki
authors.initials: T
authors.lastname: Moro-Oka
authors.forename: Yukihide
authors.initials: Y
authors.lastname: Iwamoto
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D001696:Biomechanical Phenomena; D005260:Female; D020342:Finite Element Analysis; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging*; D008297:Male; D010027:Osteotomy / Q000009:adverse effects*; D011859:Radiography; D012086:Reoperation; D013977:Tibia / Q000000981:diagnostic imaging* / Q000601:surgery*; D017211:Treatment Failure; D016474:Weight-Bearing