The reduction of volumetric wear continues to be one of the imminent challenges for the orthopaedic research community in the area of ultra-high molecular weight polyethylene (UHMWPE) joint replacement components. Retrieval analyses are necessary to determine the relationship between in vitro hip simulator predictions and actual wear performance in vivo. To quantify short term wear in retrieved highly crosslinked acetabular components it is necessary to differentiate between the initial surface morphology (dominated by manufacturer's machining marks) and the smaller scale surface features associated with in vivo adhesive/abrasive wear mechanisms. We have developed and validated a technique for deconvolution of as-manufactured versus in vivo generated surface topology from retrieved, highly crosslinked polyethylene acetabular inserts. Surface topology was characterized by white light interferometry with advanced texture analysis software. A Fourier transform algorithm was used to deconvolve the low-frequency features (i.e., waviness) such as machining marks, from the high-frequency features (i.e., roughness). Twenty-one (21) short-term (less than 24 months) conventional and highly crosslinked retrievals from different manufacturers were evaluated in this study. The wear surfaces in the short-term retrievals were deconvolved using the cut-off frequencies from the new inserts. The frequency distribution and magnitude of the machining marks were found to be material and manufacturer specific. This study highlights the importance of quantitative techniques, such as white light interferometry for distinguishing between initial and in vivo generated surface morphology. The topology observed in the crosslinked retrievals was consistent with the surface damage mechanisms previously observed in conventional UHMWPE components, namely macroscopic and microscopic adhesive/abrasive wear.
Author Information
Kurtz, SM
Exponent, Inc., Philadelphia, PASchool of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA
Turner, J
School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA
Herr, M
Exponent, Inc., Philadelphia, PA
Edidin, AA
School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA
Domestic orders are delivered via United Parcel Service (UPS) or United States Postal Service (USPS). Transit
times average 3 to 5 business days. Please be aware that UPS will not deliver packages to Post Office Boxes.
International orders are delivered via courier post services which can be either a postal service, courier
service, or a combination of both. Standard Service is untraceable. Please allow 4-7 weeks for delivery.
Please be aware that carriers will not deliver packages to Post Office Boxes. Because of the variability of
customs processes and procedures in different countries, ASTM International cannot guarantee transit times to
international destinations. Customs duty and taxes are the responsibility of the consignee.
Shipping & Handling charges follow the rate schedule, below:
Order Total
Shipping & Handling Fee (US Domestic)
Up to $50.00
$18.72
$50.01 to $100.00
$20.80
$100.01 to $150.00
$29.52
$150.01 to $250.00
$39.09
$250.01 to $500.00
$56.25
$500.01 to $750.00
$76.42
$750.01 to $1000.00
$93.15
$1000.01 to $1500.00
$121.27
$1500.01 to $2500.00
$158.38
$2500.01 to $4999.00
$209.04
$5000.00 to higher
FREE
Order Total
Shipping & Handling Fee (International)
Up to $50.00
$68.72
$50.01 to $100.00
$70.80
$100.01 to $150.00
$79.52
$150.01 to $250.00
$89.09
$250.01 to $500.00
$106.25
$500.01 to $750.00
$126.42
$750.01 to $1000.00
$143.15
$1000.01 to $1500.00
$171.27
$1500.01 to $2500.00
$208.38
$2500.01 to $4999.00
$259.04
$5000.00 to higher
FREE
Shipping and Handling charges are approximate. Additional charges may be incurred if your order requires multiple shipments. This does not apply to complete sets and sections.