This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow CME: Take the activities for this article:
 Adult Knee Reconstruction Test 5: Knee Arthroplasty
CME 2: April, May, June 2004
Right arrow [Supplementary Material]
Right arrow Letters to the Editor: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when Letters to the Editor are posted
Right arrow Alert me if a correction is posted
Services
Right arrow E-mail this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My File Cabinet
Right arrow Download to citation manager
Right arrow Rights and Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Collier, M. B.
Right arrow Articles by Engh, G. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Collier, M. B.
Right arrow Articles by Engh, G. A.
Related Collections
Right arrow Adult Knee
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us   Add to Facebook   Add to Technorati   Add to Twitter  
What's this?
The Journal of Bone and Joint Surgery (American) 86:763-769 (2004)
© 2004 The Journal of Bone and Joint Surgery, Inc.

Shelf Age of the Polyethylene Tibial Component and Outcome of Unicondylar Knee Arthroplasty

Matthew B. Collier, MS1, C. Anderson Engh, Jr., MD1 and Gerard A. Engh, MD1

1 Anderson Orthopaedic Research Institute, P.O. Box 7088, Alexandria, VA 22307. E-mail address for M.B. Collier: collier{at}aori.org

Investigation performed at the Anderson Orthopaedic Research Institute, Alexandria, Virginia

The authors did not receive grants or outside funding in support of their research or preparation of this manuscript. They did not receive payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. A commercial entity (INOVA Health Care Services, Falls Church, Virginia) paid or directed, or agreed to pay or direct, benefits to a research fund, foundation, educational institution, or other charitable or nonprofit organization with which the authors are affiliated or associated.

Background: A recent report linked shelf-aging of unicondylar polyethylene tibial components with accelerated fatigue wear and rapid failure. We retrospectively reviewed our experiences with another unicondylar knee system to investigate the relationship between the shelf age of the polyethylene components and clinical outcome.

Methods: One hundred Single Compartment Replacement unicompartmental knee arthroplasties were performed with cement between 1990 and 1996. The median shelf age for the polyethylene inserts was 1.7 years. At the time of the review, four knees had been lost to follow-up, sixteen were in patients who had died, and nineteen had been revised. Sixty-one knee replacements remained in situ at a mean and standard deviation of 8 ± 2 years postoperatively.

Results: With revision as the end point, Kaplan-Meier survivorship analysis demonstrated a six-year rate of survival of 96% when the shelf age of the insert was less than the median shelf age but only 71% when the median shelf age was exceeded. Fatigue wear was identified on all retrieved components except for two that had shelf ages under one year and had been revised within three years. At four to six years of clinical follow-up, the group of knees in which the median shelf age had been exceeded also had poorer Knee Society knee scores and function scores.

Conclusions: Aging on the shelf accelerated fatigue failure of polyethylene inserts sterilized with gamma irradiation in air and compromised our intermediate-term clinical outcomes with this unicondylar knee replacement system. Attention to the relationship between the shelf age and the clinical performance of the polyethylene component continues to be warranted with unicondylar knee arthroplasty implants.

Level of Evidence: Therapeutic study, Level III-2 (retrospective cohort study). See Instructions to Authors for a complete description of levels of evidence.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Facebook Facebook   Add to Technorati Technorati   Add to Twitter Twitter    What's this?


This article has been cited by other articles:


Home page
 J Am Acad Orthop SurgHome page
R. D. Crowninshield and O. K. Muratoglu
How have new sterilization techniques and new forms of polyethylene influenced wear in total joint replacement?
J. Am. Acad. Ortho. Surg., July 1, 2008; 16(suppl_1): S80 - S85.
[Abstract] [Full Text] [PDF]

Home page
 J Am Acad Orthop SurgHome page
T. Borus and T. Thornhill
Unicompartmental Knee Arthroplasty
J. Am. Acad. Ortho. Surg., January 1, 2008; 16(1): 9 - 18.
[Abstract] [Full Text] [PDF]

Home page
 JBJSHome page
M. B. Collier, C. A. Engh Jr., J. P. McAuley, and G. A. Engh
Factors Associated with the Loss of Thickness of Polyethylene Tibial Bearings After Knee Arthroplasty
J. Bone Joint Surg. Am., June 1, 2007; 89(6): 1306 - 1314.
[Abstract] [Full Text] [PDF]

Home page
 JBJSHome page
M. J. Archibeck and R. E. White Jr.
What's New in Adult Reconstructive Knee Surgery
J. Bone Joint Surg. Am., July 1, 2005; 87(7): 1656 - 1666.
[Full Text] [PDF]