title: The P.F.C. sigma RP-F TKA designed for improved performance: a matched-pair study.
abstract: The press fit condylar P.F.C. Sigma RP-F (rotating-platform, high flexion) knee is designed to provide a range of motion (ROM) of 155 degrees without compromising wear, polyethylene contact stresses, patellofemoral tracking, or stability. The first 50 TKA surgeries using the Sigma RP-F knee performed at the author's institution were matched to 50 rotating-platform knees for age, sex, body mass index, preoperative diagnosis, duration of follow-up, and preoperative ROM to determine the effect of design on postoperative ROM. The mean increase in active ROM in the Sigma RP-F group was 17 degrees, compared with 6 degrees in the rotating-platform group (P =.0011). The mean increase in active ROM in patients who had less than 120 degrees of preoperative motion was 27 degrees in the Sigma RP-F group, compared with 16 degrees in the rotating-platform group (P = .006). With the new P.F.C. Sigma RP-F design, greater ROM can be achieved independent of preoperative ROM.
authors.affiliation: Department of Orthopedic Surgery, Lenox Hill Hospital, New York, NY 10021, USA.
authors.forename: Sanjay K
authors.initials: SK
authors.lastname: Gupta
authors.forename: Amar S
authors.initials: AS
authors.lastname: Ranawat
authors.forename: Vineet
authors.initials: V
authors.lastname: Shah
authors.forename: Bashir A
authors.initials: BA
authors.lastname: Zikria
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Zikria
authors.forename: Chitranjan S
authors.initials: CS
authors.lastname: Ranawat
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D016555:Matched-Pair Analysis; D008875:Middle Aged; D011474:Prosthesis Design; D016059:Range of Motion, Articular