title: Morphological classification of the femoral trochlear groove based on a quantitative measurement of computed tomographic models.
abstract: OBJECTIVE
  This study aimed to investigate the natural morphology of the femoral trochlear groove based on quantitative measurement.
  
  
  METHODS
  Computed tomographic femur models of 50 male and 50 female healthy Chinese adults (30-60 years) were analysed using three-dimensional software. Coaxial cutting planes (15° increments) rotating about the trochlear groove axis from the proximal to distal point were created, followed by the deepest point of the trochlear groove marked at each cross section. The shape, position, and orientation of the trochlear groove were analysed.
  
  
  RESULTS
  The trochlear groove was located laterally relative to the mechanical axis and consisted of the laterally oriented proximal part and medially oriented distal part. Based on the turning points located on different cross sections, the trochlear groove was classified into four types: types 45°, 60°, 75°, and 90°. The mediolateral position relative to the mechanical axis was types 45°, 60°, 75°, and 90°, from the lateral to medial side, while the distal parts of them extended along the same path. The orientation of the trochlear groove was relatively consistent and smooth, which oriented at approximately 1° medially between two adjacent segments, except at approximately 10° medially at the turning point.
  
  
  CONCLUSIONS
  The trochlear groove tracking varies greatly amongst a population that is mainly categorized into four types. This study may be helpful for better understanding of the natural trochlear groove anatomy, prosthetic design modification, and provide the reference value for studying patellofemoral diseases such as patellar maltracking and trochlear dysplasia.
  
  
  METHODS
  Prospective study, Level II.
authors.affiliation: Department of Orthopaedic Surgery, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, 639 Zhizaoju Road, Shanghai, 200011, China.
authors.forename: Shichang
authors.initials: S
authors.lastname: Chen
authors.affiliation: Shanghai Key Laboratory of Orthopaedic Implants, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Du
authors.affiliation: Department of Orthopaedic Surgery, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, 639 Zhizaoju Road, Shanghai, 200011, China.
authors.forename: Mengning
authors.initials: M
authors.lastname: Yan
authors.affiliation: Department of Orthopaedic Surgery, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, 639 Zhizaoju Road, Shanghai, 200011, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Yue
authors.affiliation: Shanghai Key Laboratory of Orthopaedic Implants, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China. drwangyou@163.com.|Department of Orthopaedic Surgery, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, 639 Zhizaoju Road, Shanghai, 200011, China. drwangyou@163.com.
authors.forename: You
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000328:Adult; D005260:Female; D005269:Femur / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D064368:Healthy Volunteers; D006801:Humans; D021621:Imaging, Three-Dimensional; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D057071:Patellofemoral Joint / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D011446:Prospective Studies; D011474:Prosthesis Design; D014057:Tomography, X-Ray Computed
keywords: Chinese population; Computed tomography; Femoral trochlear groove; Morphological analysis; Total knee arthroplasty