title: Relationship between range of motion and femoral rollback in total knee arthroplasty.
abstract: OBJECTIVE
  The aim of this study was to evaluate the relation between femoral rollback and range of motion (ROM) in patients with cruciate retaining (CR) and posterior stabilized (PS) total knee arthroplasty (TKA).
  
  
  METHODS
  The study included 38 knees of 31 patients (26 female and 5 male) with primary knee arthrosis who underwent TKA. The posterior cruciate ligament (PCL) was sacrificed in 24 knees in the PS group and preserved in 14 in the CR group. Mean follow-up was 30.6 months. Patients were submitted to fluoroscopic lateral evaluation for ROM and femoral rollback assessment.
  
  
  RESULTS
  Average ROM of the CR group was 106.43±9º and 105.43±11.7º for the PS group (p=0.78). Average femoral rollback was 10.5±9.7 mm and was significantly lower in the CR group (5.8±6.5 mm) than the PS group (13.2±10.5 mm) (p=0.026615). While there was no correlation between the femoral rollback and ROM for CR prostheses (p=0.78 and r=0.8), there was a significant correlation for PR prostheses (p=0.01 and r=0.49) with regression pointing to an increase of 0.545 degrees ROM for each unit of femoral rollback.
  
  
  CONCLUSIONS
  Despite increase in femoral rollback and its relation with ROM in PS TKA, there were no differences in ROM between CR and PS TKA.
authors.affiliation: Faculty of Medicine, Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Lúcio Honório
authors.initials: LH
authors.lastname: Carvalho
authors.affiliation: The Knee Group, Madre Teresa Hospital, Belo Horizonte, Brazil.
authors.forename: Eduardo Frois
authors.initials: EF
authors.lastname: Temponi
authors.affiliation: The Knee Group, Madre Teresa Hospital, Belo Horizonte, Brazil.
authors.forename: Luiz Fernando Machado
authors.initials: LF
authors.lastname: Soares
authors.affiliation: The Knee Group, Madre Teresa Hospital, Belo Horizonte, Brazil.
authors.forename: Matheus Jacques Braga
authors.initials: MJ
authors.lastname: Gonçalves
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D016059:Range of Motion, Articular