title: Total knee replacement following intra-articular malunion.
abstract: BACKGROUND
  There is a lack of data on the management of osteoarthritis of the knee associated with intra-articular malunion. The present study sought to analyze and report results of total knee replacement (TKR) in this indication, including complications and technical specificities.
  
  
  OBJECTIVE
  TKR for osteoarthritis of the knee associated with intra-articular malunion entails an elevated risk of complication, with impaired functional results.
  
  
  OBJECTIVE
  To test this hypothesis in a retrospective series of 74 cases of osteoarthritis of the knee associated with intra-articular malunion.
  
  
  METHODS
  A multicenter retrospective series collated the records of 74 patients (mean age, 63 ± 14 years) who underwent TKR for post-traumatic osteoarthritis of the knee associated with intra-articular malunion between 2000 and 2008. Mean trauma-to-TKR interval was 21.8 ± 19 years (range 1 to 56 years). Patients were assessed clinically and radiologically at last follow-up, using the Knee Society score as modified by the Western France Orthopedic Society (Société orthopédique de l'Ouest).
  
  
  RESULTS
  At a mean overall follow-up of 4 ± 3 years (range 1 to 9 years), mean knee score improved from 25 ± 12 to 85 ± 7 (P<0.001) and mean functional score from 52 ± 13 to 66 ± 10 (P=0.004). Mean flexion gain was 6°: mean preoperative flexion, 104° ± 28° (10° to 150°), vs. 110° ± 19° (20° to 130°) at follow-up. Nineteen patients (26%) had complications, 13 of which were severe and liable to affect the functional result: three extensor system avulsions, four infections, five cases of stiffness and one of instability.
  
  
  CONCLUSIONS
  The present results highlight an elevated rate of complications, with poorer clinical results than those found with osteoarthritis of the knee secondary to constitutional deformity. The initial trauma, with associated hemarthrosis, and sometimes iterative surgery to reduce and fix the initial fracture, induce fibrosis and synovial attachments, leading to stiffness and hindering exposure. The patient should be informed, and warned that postoperative flexion amplitude may be improved but is bound to remain limited, especially in case of initial stiffness.
  
  
  METHODS
  Level IV: non-comparative retrospective study.
authors.affiliation: Arthritis Surgery Center, Sainte-Marguerite hospital, University Hospital Center South, 270, boulevard Sainte-Marguerite, 13009 Marseille, France.
authors.forename: S
authors.initials: S
authors.lastname: Parratte
authors.forename: P
authors.initials: P
authors.lastname: Boyer
authors.forename: P
authors.initials: P
authors.lastname: Piriou
authors.forename: J-N
authors.initials: JN
authors.lastname: Argenson
authors.forename: G
authors.initials: G
authors.lastname: Deschamps
authors.forename: P
authors.initials: P
authors.lastname: Massin
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000379:methods; D005260:Female; D017759:Fractures, Malunited / Q000601:surgery*; D006801:Humans; D057072:Intra-Articular Fractures / Q000150:complications / Q000601:surgery*; D007719:Knee Joint / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000150:complications; D016059:Range of Motion, Articular / Q000502:physiology; D012189:Retrospective Studies