title: Comparison of intraoperative anthropometric measurements of the proximal tibia and tibial component in total knee arthroplasty.
abstract: BACKGROUND
  Precise matching of the tibial component and resected bony surfaces and proper rotational implanting of the tibial component are crucial for successful total knee arthroplasty. We aimed to analyze the exact anthropometric proximal tibial data of Japanese patients undergoing total knee arthroplasty and correlate the measurements with the dimensions of current total knee arthroplasty systems.
  
  
  METHODS
  A total of 703 knees in 566 Japanese patients who underwent total knee arthroplasty for osteoarthritis were included. The bone resection in the proximal tibia was performed perpendicular to the tibial axis in the frontal plane. Measurements of the proximal tibia were intraoperatively obtained after proximal tibial preparation.
  
  
  RESULTS
  There were significant positive correlations between the lateral anteroposterior and medial anteroposterior and mediolateral dimensions. A progressive decrease in the mediolateral/lateral anteroposterior ratio with an increasing lateral anteroposterior dimension or the mediolateral/anteroposterior ratio with an increasing anteroposterior dimension was observed. The lateral anteroposterior dimension was smaller than the medial anteroposterior dimension by a mean of 4.8 ± 2.0 mm. The proximal tibia exhibited asymmetry between the lateral and medial plateaus. A comparison of the morphological data and dimensions of the implants, one of which was a symmetric tibial component (NexGen) and the others were asymmetric (Genesis II and Persona), indicated that an asymmetric tibial component could be beneficial to maximize tibial plateau coverage.
  
  
  CONCLUSIONS
  This study provided important reference data for designing a proper tibial component for Japanese people. The proximal tibial cut surface was asymmetric. There was wide dispersion in the lateral anteroposterior, medial anteroposterior, and mediolateral dimensions depending on the patient. Our data showed that the tibial components of the Genesis II and Persona rather than that of the NexGen may be preferable for Japanese people because of their asymmetric design.
authors.affiliation: Department of Orthopedic Surgery, Tohoku Orthopedic Clinic, 4-9-22 Kamiyagari, Izumi-ku, Sendai-city 981-3121, Japan.
authors.forename: Naohisa
authors.initials: N
authors.lastname: Miyatake
authors.affiliation: Department of Orthopedic Surgery, Tohoku Orthopedic Clinic, 4-9-22 Kamiyagari, Izumi-ku, Sendai-city 981-3121, Japan. Electronic address: t-sugita@tohokuseikei.com.
authors.forename: Takehiko
authors.initials: T
authors.lastname: Sugita
authors.affiliation: Department of Orthopedic Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai-city 980-8574, Japan.
authors.forename: Toshimi
authors.initials: T
authors.lastname: Aizawa
authors.affiliation: Department of Orthopedic Surgery, Tohoku Orthopedic Clinic, 4-9-22 Kamiyagari, Izumi-ku, Sendai-city 981-3121, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Sasaki
authors.affiliation: Department of Orthopedic Surgery, Tohoku Orthopedic Clinic, 4-9-22 Kamiyagari, Izumi-ku, Sendai-city 981-3121, Japan.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Maeda
authors.affiliation: Department of Orthopedic Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai-city 980-8574, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kamimura
authors.affiliation: Department of Orthopedic Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai-city 980-8574, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Fujisawa
authors.affiliation: Department of Orthopedic Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai-city 980-8574, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takahashi
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000886:Anthropometry; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007564:Japan; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000601:surgery*; D012189:Retrospective Studies; D018570:Risk Assessment; D012737:Sex Factors; D013977:Tibia / Q000033:anatomy & histology*; D016896:Treatment Outcome