title: Post damage in contemporary posterior-stabilized tibial inserts: influence of implant design and clinical relevance.
abstract: The mechanisms of damage at the polyethylene post in 3 contemporary tibial insert designs were evaluated and compared with a historical standard (Insall-Burstein II; Zimmer, Warsaw, Ind). One hundred five gamma sterilized posterior-stabilized tibial inserts were revised after an average of 4.7 years (0.05-13.6 years). Retrievals were classified according to their designs: Insall-Burstein II (n = 28); PFC (Johnson & Johnson, Raynham, Mass; n = 30); NexGen (Zimmer; n = 32); and Scorpio (Stryker Orthopaedics, Mahwah, NJ; n = 15). Reasons for revision and patient details were available. Surface damage scoring and photogrammetry were performed on all the retrieved tibial inserts. Oxidation analysis was carried out for traceable historical, gamma air-sterilized and conventional, gamma inert-sterilized tibial inserts (n = 61) with the use of infrared spectroscopy. The posts for all 3 contemporary designs exhibited damage similar to the historical controls. Articular, post, and backside damage scores significantly increased with implantation time. Post damage was insensitive to design and patient factors but was exacerbated by oxidation. An association between damage at the post and articular surface was also confirmed. Logistic models suggested an interaction between post damage, backside surface damage, and implant loosening.
authors.affiliation: Implant Research Center, School of Biomedical Engineering, Science and Health Systems, Drexel University, 3401 Market Street. Suite 300, Philadelphia, PA 19104, USA.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Medel
authors.forename: Steven M
authors.initials: SM
authors.lastname: Kurtz
authors.forename: Peter F
authors.initials: PF
authors.lastname: Sharkey
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Austin
authors.forename: Gregg R
authors.initials: GR
authors.lastname: Klein
authors.forename: Alexis R
authors.initials: AR
authors.lastname: Cohen
authors.forename: Hina
authors.initials: H
authors.lastname: Patel
authors.forename: Victor M
authors.initials: VM
authors.lastname: Goldberg
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Kraay
authors.forename: Clare M
authors.initials: CM
authors.lastname: Rimnac
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000601:surgery; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation* / Q000379:methods; D005260:Female; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery; D010084:Oxidation-Reduction; D020959:Polyethylene; D011474:Prosthesis Design; D011475:Prosthesis Failure / Q000009:adverse effects* / Q000209:etiology*; D012086:Reoperation; D017550:Spectroscopy, Fourier Transform Infrared; D013977:Tibia / Q000601:surgery*
chemical_list: D020959:Polyethylene