title: Patient, implant, and alignment factors associated with revision of medial compartment unicondylar arthroplasty.
abstract: The investigators reviewed 245 fixed-bearing unicondylar arthroplasties that one surgeon performed as treatment of medial compartment osteoarthritis between 1988 and 1997 using a variety of cemented metal-backed tibial components and gamma-irradiated-in-air polyethylene bearings. Multivariate statistical analysis was used to evaluate how the event of revision was influenced by 3 patient factors, 3 implant factors, and 7 factors assessed from preoperative and early postoperative radiographs. Five factors were statistically associated with revision: (younger) patient age, (thinner) tibial component initial thickness, (longer) polyethylene shelf age, (lesser) angular reduction of medial tibial plateau varus, and (more varus) postoperative hip-knee-ankle angle. Besides illustrating deleterious consequences of using gamma-irradiated-in-air polyethylene in medial unicompartmental arthroplasty, our results support reducing varus angulation of the medial tibial plateau and knee at surgery.
authors.affiliation: Anderson Orthopaedic Research Institute, Alexandria, VA, USA.
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Collier
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Eickmann
authors.forename: Fumio
authors.initials: F
authors.lastname: Sukezaki
authors.forename: James P
authors.initials: JP
authors.lastname: McAuley
authors.forename: Gerard A
authors.initials: GA
authors.lastname: Engh
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects* / Q000379:methods; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging; D007720:Knee Prosthesis / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010003:Osteoarthritis / Q000601:surgery*; D020959:Polyethylene / Q000009:adverse effects*; D016016:Proportional Hazards Models; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012307:Risk Factors; D013977:Tibia / Q000033:anatomy & histology / Q000601:surgery
chemical_list: D020959:Polyethylene