Are component positioning and prosthesis size associated with hip resurfacing failure?
Abstract
BACKGROUND: Recent studies suggest that there is a learning curve for metal-on-metal
hip resurfacing. The purpose of this study was to assess whether implant positioning
changed with surgeon experience and whether positioning and component sizing were
associated with implant longevity. METHODS: We evaluated the first 361 consecutive
hip resurfacings performed by a single surgeon, which had a mean follow-up of 59 months
(range, 28 to 87 months). Pre and post-operative radiographs were assessed to determine
the inclination of the acetabular component, as well as the sagittal and coronal femoral
stem-neck angles. Changes in the precision of component placement were determined
by assessing changes in the standard deviation of each measurement using variance
ratio and linear regression analysis. Additionally, the cup and stem-shaft angles
as well as component sizes were compared between the 31 hips that failed over the
follow-up period and the surviving components to assess for any differences that might
have been associated with an increased risk for failure. RESULTS: Surgeon experience
was correlated with improved precision of the antero-posterior and lateral positioning
of the femoral component. However, femoral and acetabular radiographic implant positioning
angles were not different between the surviving hips and failures. The failures had
smaller mean femoral component diameters as compared to the non-failure group (44
versus 47 millimeters). CONCLUSIONS: These results suggest that there may be differences
in implant positioning in early versus late learning curve procedures, but that in
the absence of recognized risk factors such as intra-operative notching of the femoral
neck and cup inclination in excess of 50 degrees, component positioning does not appear
to be associated with failure. Nevertheless, surgeons should exercise caution in operating
patients with small femoral necks, especially when they are early in the learning
curve.
Type
Journal articleSubject
AdolescentAdult
Aged
Arthroplasty, Replacement, Hip
Equipment Failure Analysis
Female
Hip Prosthesis
Humans
Male
Middle Aged
Prosthesis Failure
Retrospective Studies
Young Adult
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https://hdl.handle.net/10161/10410Published Version (Please cite this version)
10.1186/1471-2474-11-227Publication Info
Marker, David R; Zywiel, Michael G; Johnson, Aaron J; Seyler, Thorsten M; & Mont,
Michael A (2010). Are component positioning and prosthesis size associated with hip resurfacing failure?.
BMC Musculoskelet Disord, 11. pp. 227. 10.1186/1471-2474-11-227. Retrieved from https://hdl.handle.net/10161/10410.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Show full item recordScholars@Duke
Thorsten Markus Seyler
Associate Professor in Orthopaedic Surgery
Based on a recent market research survey, the U.S. demand for implantable medical
devices is forecast to increase 7.7% annually to $52 billion in 2015. While orthopedic
implants remain the largest segment, implantable devices are frequently used in urology,
cardiovascular specialties, neurology, gynecology, and otolaryngology. With the increased
usage of implantable devices, the number of biofilm-associated infections has emerged
as a significant clinical problem because biofilms are oft

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