title: In vivo comparisons of patellofemoral kinematics before and after ADVANCE Medial-Pivot total knee arthroplasty.
abstract: OBJECTIVE
  ADVANCE Medial-Pivot (MP) (Wright Medical Technology, Arlington, TN, USA) total knee arthroplasty (TKA) was developed to replicate normal tibiofemoral knee joint kinematics, allowing medial-pivot knee motion. The design concept of the prosthesis is unique; therefore, the influence on the patellofemoral knee joint remains unclear at present. The purpose of this study was to determine the in vivo patellofemoral kinematics with ADVANCE MP TKA and compare them with the pre-operative conditions.
  
  
  METHODS
  ADVANCE MP TKA was performed in ten subjects with osteoarthritis (OA). At before and one month after surgery, lateral radiographs with weight-bearing at maximum extension, 30, 60 and 90° were taken, and patella flexion angle (PF), tibiopatellar angle (TP) and estimated patellofemoral contact point (PC) were evaluated, according to a previously reported method.
  
  
  RESULTS
  In PF and TP, there was no statistically significant change between pre-operative and postoperative values. Pre-operative PC reached its peak at 90°; however, its peak was at 60° at one month after surgery. Postoperative PC at maximum extension was significantly higher compared to before surgery.
  
  
  CONCLUSIONS
  The results in this study indicated that ADVANCE MP TKA changed patellofemoral joint kinematics compared to before surgery. Early postoperative evaluation is the limitation of this study; however, we consider that the results in this study might be one of the keys to resolving the kinematic features of this prosthesis, helping clinicians to comprehend this prosthesis.
authors.affiliation: Department of Orthopaedic Surgery, Hyogo Rehabilitation Centre Central Hospital, 1070 Akebono-cho, Nishi-ku, Kobe 651-2181, Japan. wavedreamer17@yahoo.co.jp
authors.forename: Kazunari
authors.initials: K
authors.lastname: Ishida
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Tsumura
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Chinzei
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kitagawa
authors.forename: Seiji
authors.initials: S
authors.lastname: Kubo
authors.forename: Takaaki
authors.initials: T
authors.lastname: Chin
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Iguchi
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Akisue
authors.forename: Kotaro
authors.initials: K
authors.lastname: Nishida
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kurosaka
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Kuroda
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D001696:Biomechanical Phenomena; D006801:Humans; D007720:Knee Prosthesis; D020370:Osteoarthritis, Knee / Q000503:physiopathology / Q000601:surgery; D057071:Patellofemoral Joint / Q000503:physiopathology / Q000601:surgery*; D011183:Postoperative Complications; D057234:Preoperative Period; D011474:Prosthesis Design; D016059:Range of Motion, Articular; D016896:Treatment Outcome; D016474:Weight-Bearing