title: Three different cruciate-sacrificing TKA designs: minor intraoperative kinematic differences and negligible clinical differences.
abstract: OBJECTIVE
  The goal of this study was to compare three types of mobile-bearing posterior cruciate ligament (PCL)-sacrificing TKA. The hypothesis was that the three designs provide differences in flexion stability and femoral rollback and improved clinical score at 2-year follow-up.
  
  
  METHODS
  Three groups of patients, divided according to implant design, were analysed retrospectively. All operations were guided by a non-image-based navigation system that recorded relative femoral and tibial positions in native and implanted knees during: passive range of motion and anterior drawer test at 90° flexion. WOMAC, KSS and SF36 scores were collected pre-operatively and at 2-year follow-up.
  
  
  RESULTS
  There are no differences in kinematic or clinical performance of the three implants, except for the antero-posterior translation during stress test in flexion: only Cohort B had comparable pre- and post-operative laxity test values (p < 0.001). All three TKA designs allowed to maintain pre-operative tibial rotation pattern through all range of knee flexion. All clinical scores of the three patient cohorts were significantly improved post-operatively compared to the pre-operative values (p < 0.001). Moreover, we found no differences among post-operative results of the three designs.
  
  
  CONCLUSIONS
  Despite design variations, mobile-bearing PCL-sacrificing TKA reproduces femoral rollback and screw-home with little or no difference in clinical or functional scores at a follow-up of 2 years.
  
  
  METHODS
  III.
authors: Laboratorio di Biomeccanica e Innovazione Tecnologica, Istituto Ortopedico Rizzoli, Via di Barbiano 1/10, 40136, Bologna, Italy, s.bignozzi@biomec.ior.it.
authors: Simone
authors: S
authors: Bignozzi
authors: Stefano
authors: S
authors: Zaffagnini
authors: Ibrahim
authors: I
authors: Akkawi
authors: Tedi
authors: T
authors: Marko
authors: Danilo
authors: D
authors: Bruni
authors: Maria Pia
authors: MP
authors: Neri
authors: Francesca
authors: F
authors: Colle
authors: Maurilio
authors: M
authors: Marcacci
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000379:methods*; D001696:Biomechanical Phenomena; D005260:Female; D005269:Femur / Q000503:physiopathology; D006801:Humans; D007593:Joint Instability / Q000209:etiology / Q000517:prevention & control; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000503:physiopathology / Q000601:surgery*; D016119:Posterior Cruciate Ligament / Q000601:surgery*; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D012399:Rotation; D013977:Tibia / Q000503:physiopathology