|The effect of poly sterilization on wear, osteolysis and survivorship of a press-fit cup at 10-year followup.|
|PMID: 21904891 Owner: NLM Status: MEDLINE|
|BACKGROUND: During the mid-1990s when our institution was using a press-fit porous-coated cup without supplemental initial fixation for primary THA, the manufacturer transitioned from gamma irradiation to gas plasma for the terminal sterilization of their polyethylene liners.
QUESTIONS/PURPOSES: At minimum 10-year followup, we asked whether the fixation achieved by solely relying on a press-fit would be durable and how different liner sterilization methods affected radiographic wear, osteolysis, and survivorship.
PATIENTS AND METHODS: We retrospectively reviewed 373 patients who underwent 398 primary THAs with a press-fit porous-coated cup between March 1995 and December 1996. Mean age at time of surgery was 61.5 ± 13.3 years and mean followup was 10.4 ± 3.7 years. We determined reasons for revision, survivorship, femoral head penetration, osteolysis, and wear-related complications.
RESULTS: Among 20 revisions involving any component, seven were associated with wear and osteolysis. Kaplan-Meier survivorship, using component revision for any reason as an end point, was 95.7% (95% confidence interval, 93.6%-97.9%) at 10 years. Noncrosslinked liners sterilized with gas plasma demonstrated a mean head penetration rate of 0.20 ± 0.09 mm/year compared with 0.13 ± 0.07 mm/year for liners sterilized with gamma irradiation in air and 0.09 ± 0.04 mm/year for liners sterilized with gamma-irradiation with barrier packaging without oxygen. THAs with increased volumetric wear tended to demonstrate larger osteolytic lesions (r = 0.40) and there tended to be less osteolysis among the liners sterilized with gamma-irradiation with barrier packaging without oxygen. However, there was no difference in survivorship among the sterilization groups and there has been no cup or stem loosening associated with osteolysis.
CONCLUSIONS: Durable biologic fixation through 10-year followup can be achieved by solely relying on an initial press-fit. Noncrosslinking gas plasma for terminal sterilization of the polyethylene liners was associated with greater head penetration rate than gamma irradiation.
LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
|Charles A Engh; Cara C Powers; Henry Ho; Sarah E Beykirch-Padgett; Robert H Hopper; C Anderson Engh|
|Type: Comparative Study; Journal Article; Multicenter Study|
|Title: Clinical orthopaedics and related research Volume: 470 ISSN: 1528-1132 ISO Abbreviation: Clin. Orthop. Relat. Res. Publication Date: 2012 Feb|
|Created Date: 2012-01-11 Completed Date: 2012-02-27 Revised Date: 2013-06-27|
Medline Journal Info:
|Nlm Unique ID: 0075674 Medline TA: Clin Orthop Relat Res Country: United States|
|Languages: eng Pagination: 462-70 Citation Subset: AIM; IM|
|Anderson Orthopaedic Research Institute, PO Box 7088, Alexandria, VA 22307, USA.|
|APA/MLA Format Download EndNote Download BibTex|
Aged, 80 and over
Arthroplasty, Replacement, Hip / adverse effects, instrumentation*
Gamma Rays / adverse effects
Hip Joint / radiography, surgery*
Osteolysis / etiology, prevention & control*, radiography
Plasma Gases / adverse effects
Polyethylene* / radiation effects
Sterilization* / methods
|0/Plasma Gases; 9002-88-4/Polyethylene|
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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