title: Effect of posterior condylar offset on clinical results after posterior-stabilized total knee arthroplasty.
abstract: OBJECTIVE
  To determine the effect of the posterior condylar offset (PCO) on clinical results after total knee arthroplasty (TKA) using a high-flex posterior-stabilized (PS) fixed-bearing prosthesis.
  
  
  METHODS
  We prospectively studied the clinical and radiographic materials of 89 consecutive female patients (89 knees), who had undergone primary TKAs for end-stage osteoarthritis. All operations were performed by a single senior surgeon or under his supervision using the same operative technique. Based on the corrected PCO change, we divided all cases into two groups: group A (corrected PCO change ≥0 mm, 58 knees) and group B (corrected PCO change<0 mm, 31 knees). One-year postoperatively, clinical and radiographic variables from the two groups were compared by independent t-test. The associations between the corrected PCO changes and the improvements of clinical variables in all patients were analyzed by Pearson linear correlation.
  
  
  RESULTS
  One-year postoperatively, the Knee Society Scores, the Western Ontario and McMaster Universities Osteoarthritis Index, non-weight-bearing active and passive range of knee flexion, flexion contracture, extensor lag, and their improvements had no statistical differences between the two groups (all p>0.05). The corrected PCO change was not significantly correlated with the improvement of any clinical variable (all p>0.05). Group A demonstrated greater flexion than group B during active weight bearing (p<0.05).
  
  
  CONCLUSIONS
  Restoration of PCO plays an important role in the optimization of active knee flexion during weight-bearing conditions after posterior-stabilized TKA, while it has no benefit to non-weight-bearing knee flexion or any other clinical result.
authors.affiliation: Department of Orthopedics, Nankai University Tianjin Union Medical Center, Tianjin 300121, China.
authors.forename: Jian-Tao
authors.initials: JT
authors.lastname: Wang
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Qing
authors.initials: Q
authors.lastname: Liu
authors.forename: Qiang
authors.initials: Q
authors.lastname: He
authors.forename: Dong-Liang
authors.initials: DL
authors.lastname: Zhang
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ji-Xuan
authors.initials: JX
authors.lastname: Xiao
authors.forename: Xin
authors.initials: X
authors.lastname: Mu
authors.forename: Ming
authors.initials: M
authors.lastname: Hu
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology; D007720:Knee Prosthesis; D008875:Middle Aged; D010003:Osteoarthritis / Q000503:physiopathology / Q000601:surgery*; D011446:Prospective Studies; D016059:Range of Motion, Articular