title: A randomized controlled trial comparing "high-flex" vs "standard" posterior cruciate substituting polyethylene tibial inserts in total knee arthroplasty.
abstract: The purpose of this study is to compare the range of motion and clinical outcomes of a standard posterior-stabilized (PS) vs the high-flex (HF) polyethylene tibial insert of a posterior cruciate substituting total knee arthroplasty system. One hundred patients were entered into a prospective, blinded, randomized clinical trial in which 50 patients received a Genesis II PS insert and 50 patients received a Genesis II HF insert (Smith & Nephew, Memphis, TN). At an average follow-up of 2.7 years (range, 2.3-3.1 years), there were no differences in any outcome measures (Western Ontario and McMaster Universities osteoarthritis index, Short-Form 12, Knee Society clinical rating scores, anterior knee pain). There were no differences (P = .811) in average knee flexion at 2 years (standard, 123 degrees +/- 7 degrees; HF, 124 degrees +/- 7 degrees). In summary, this prospective blinded randomized clinical trial demonstrated no differences between a PS and HF polyethylene design. Long-term evaluation will be required to comment on differences in polyethylene wear and implant longevity.
authors.affiliation: London Health Sciences Center, London, Ontario, Canada.
authors.forename: Richard W
authors.initials: RW
authors.lastname: McCalden
authors.forename: Steven J
authors.initials: SJ
authors.lastname: MacDonald
authors.forename: Robert B
authors.initials: RB
authors.lastname: Bourne
authors.forename: Juliana T
authors.initials: JT
authors.lastname: Marr
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation* / Q000379:methods; D001696:Biomechanical Phenomena; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000502:physiology / Q000601:surgery*; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D020959:Polyethylene; D016119:Posterior Cruciate Ligament / Q000601:surgery*; D011446:Prospective Studies; D011474:Prosthesis Design; D016059:Range of Motion, Articular / Q000502:physiology; D016037:Single-Blind Method; D013977:Tibia / Q000601:surgery*; D016896:Treatment Outcome
chemical_list: D020959:Polyethylene