title: The tibial crest as a practical useful landmark in total knee arthroplasty.
abstract: BACKGROUND
  The middle one-third of the tibial crest in the coronal plane and the fibula in the sagittal plane are known as landmarks for extramedullary guides in total knee arthroplasty (TKA). However, there are few foundational anatomic studies about them. We conducted this study to confirm whether these landmarks are reliable.
  
  
  METHODS
  We evaluated 100 Japanese knees using 3D imaging software. We examined our data for correlations between the angle of deviation from the mechanical axis and patient-specific factors (i.e. hip-knee-ankle angle, tibial length, tibial bowing, and tibial torsion) to determine whether there are any individual factors affecting their reliability.
  
  
  RESULTS
  The mean angles between each of the axes defined by the fibula and the tibial crest with the mechanical axis were 2.9°±0.6° of valgus and 0.7°±0.9° of varus in the coronal plane and 2.2°±0.8° of posterior and 3.6°±1.0° of anterior inclination in the sagittal plane. The middle one-third of the tibial crest (TCL) was revealed as a useful landmark, especially in female patients, who possess TCLs that were within 3° of the tibial mechanical axis in the coronal plane. There were no patient-specific factors strongly affecting reliability of these landmarks.
  
  
  CONCLUSIONS
  We can use these landmarks even if the patient has tibial bowing or severe varus deformity. Although not considering soft tissue thickness, our study demonstrated that the tibial crest in the coronal and sagittal planes could be useful guidelines in performing TKAs.
  
  
  METHODS
  II.
authors.affiliation: Department of Orthopaedic Surgery, Chiba Rehabilitation Center, Japan. Electronic address: mdddd940@ybb.ne.jp.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Tsukeoka
authors.affiliation: Department of Orthopaedic Surgery, Chiba Rehabilitation Center, Japan.
authors.forename: Tae Hyun
authors.initials: TH
authors.lastname: Lee
authors.affiliation: Department of Orthopaedic Surgery, Chiba Rehabilitation Center, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Tsuneizumi
authors.affiliation: Chiba University Research Center for Frontier Medical Engineering, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Suzuki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D005360:Fibula / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D006801:Humans; D021621:Imaging, Three-Dimensional; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D017755:Prosthesis Fitting / Q000379:methods*; D015203:Reproducibility of Results; D012727:Sex Characteristics; D013977:Tibia / Q000033:anatomy & histology / Q000000981:diagnostic imaging*