title: Malposition of the tibial tubercle during flexion in knees with patellofemoral arthritis.
abstract: OBJECTIVE
  To assess the mechanisms contributing to the induction of patellofemoral arthritis (PF-OA).
  
  
  METHODS
  A computed tomography scan was taken at three levels of the lower extremity in full extension and at 30 degrees of flexion. The cuts were superimposed and 12 parameters were compared in 17 PF-OA knees and 27 normal knees to assess the rotation angle of the tibial tubercle.
  
  
  RESULTS
  Although the tibial tubercle was in almost the same position in full extension in the normal and PF-OA knees, it was positioned significantly laterally at 30 degrees of flexion in PF-OA knees. Also the articular surface of the lateral femoral condyle was significantly narrower or steeper in PF-OA knees.
  
  
  CONCLUSIONS
  Anatomic variations and mechanical abnormalities were identified in the PF-OA knees.
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, Kyushu University, Fukuoka City, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Nagamine
authors.forename: H
authors.initials: H
authors.lastname: Miura
authors.forename: Y
authors.initials: Y
authors.lastname: Inoue
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
authors.forename: K
authors.initials: K
authors.lastname: Urabe
authors.forename: Y
authors.initials: Y
authors.lastname: Okamoto
authors.forename: M
authors.initials: M
authors.lastname: Nishizawa
authors.forename: Y
authors.initials: Y
authors.lastname: Iwamoto
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005269:Femur / Q000473:pathology; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D008875:Middle Aged; D009068:Movement; D010003:Osteoarthritis / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D010329:Patella / Q000473:pathology; D013977:Tibia / Q000000981:diagnostic imaging / Q000473:pathology*; D014057:Tomography, X-Ray Computed