title: Does a new implant design with more physiological kinematics provide better results after knee arthroplasty?
abstract: BACKGROUND
  Improved knee kinematics is one of the major goals to obtain better satisfaction after total knee arthroplasty. This study examined whether a guided motion knee design improves functional outcome and satisfaction as compared to a conventional design.
  
  
  METHODS
  In a retrospective manner, from January 2005 to December 2008, patients with two different kinematic TKA designs were enrolled. The 150 patients were divided into two groups: guided motion group (77) with kinematic design (Journey) and control group (73) with no kinematic design (LCS). All the patients had the same surgical technique and postoperative protocols. The functional and radiographic results were interpreted with the Hospital for Special Surgery (HSS) knee score and WOMAC score.
  
  
  RESULTS
  After a mean follow-up of 84.2months, the guided motion group had higher mean postoperative range of motion (p=0.022), functional status in the WOMAC function subscale (p=0.002), but had higher residual pain in the WOMAC pain subscale (p=0.018 and p=0.013) and higher iliotibial band syndrome incidence (6.6% vs 0%; p=0.02). There were no significant differences in HSS score between the two groups. No differences were seen between groups in patient satisfaction in the WOMAC total score (p=0.46) and survival rate.
  
  
  CONCLUSIONS
  The guided motion design can improve functional status according to WOMAC but not to HSS knee scores. Poorer pain scores and no higher patient satisfaction were observed with this kinematic design.
authors.affiliation: Hospital General Universitario Gregorio Marañón, Spain. Electronic address: pablo.sanzruiz@gmail.com.
authors.forename: Pablo
authors.initials: P
authors.lastname: Sanz-Ruiz
authors.affiliation: Hospital General Universitario Gregorio Marañón, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Carbo-Laso
authors.affiliation: Hospital General Universitario Gregorio Marañón, Spain.
authors.forename: Berta
authors.initials: B
authors.lastname: Alonso-Polo
authors.affiliation: Hospital General Universitario Gregorio Marañón, Spain.
authors.forename: Jose Antonio
authors.initials: JA
authors.lastname: Matas-Diez
authors.affiliation: Hospital General Universitario Gregorio Marañón, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Vaquero-Martín
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018771:Arthralgia / Q000503:physiopathology / Q000601:surgery*; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation*; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery*; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000503:physiopathology / Q000601:surgery*; D011474:Prosthesis Design; D016059:Range of Motion, Articular; D012189:Retrospective Studies
keywords: Guided motion arthroplasty; Knee arthroplasty; Knee kinematic; Patient satisfaction