title: Increase of patellofemoral height has decreased maximum knee flexion after total knee arthroplasty of posterior cruciate-substituting prosthesis in a clinical series.
abstract: BACKGROUND
  Biomechanical studies in vitro suggested that patellofemoral (PF) stuffing would cause knee flexion restriction after total knee arthroplasty (TKA). We investigated the effect of anterior PF stuffing on the postoperative knee flexion after cemented TKA of posterior cruciate-substituting (PS) design.
  
  
  METHODS
  A retrospective review of 140 primary TKAs for osteoarthritis with an average age of 68.5 was conducted. The patella was resurfaced. The height of PF joint and the patella thickness were evaluated radiographically, preoperatively and 2-year postoperatively.
  
  
  RESULTS
  The maximum flexion angle was 129.7° (standard deviation: SD 16.9) pre-operatively and 129.3° (SD 11.9) 2-year postoperatively. The increase in height was associated with the differences in maximum flexion angle between preoperatively and postoperatively (R = 0.254 P < 0.01). The patella thickness change did not show any significant influences.
  
  
  CONCLUSIONS
  The increase in patellofemoral volume has decreased range of motion after total knee arthroplasty of posterior cruciate-substituting prosthesis.
authors.affiliation: Department of Orthopaedic Surgery, Tokyo Medical and Dental University, Hospital for Medicine, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Katagiri
authors.affiliation: Department of Orthopaedic Surgery, Tokyo Medical and Dental University, Hospital for Medicine, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Department of Orthopaedic Surgery, Tokyo Medical and Dental University, Hospital for Medicine, Japan.
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Department of Orthopaedic Surgery, Tokyo Medical and Dental University, Hospital for Medicine, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Koga
authors.affiliation: Department of Orthopaedic Surgery, Tokyo Medical and Dental University, Hospital for Medicine, Japan.
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Yagishita
authors.affiliation: Department of Orthopaedic Surgery, Tokyo Medical and Dental University, Hospital for Medicine, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Sekiya
authors.affiliation: Department of Orthopaedic Surgery, Tokyo Medical and Dental University, Hospital for Medicine, Japan. Electronic address: muneta.orj@tmd.ac.jp.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Muneta
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D057071:Patellofemoral Joint / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D011474:Prosthesis Design; D016059:Range of Motion, Articular; D012189:Retrospective Studies