Are component positioning and prosthesis size associated with hip resurfacing failure?
Published online
Journal Article
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.
Full Text
- Published version (via Digital Object Identifier)
- Pubmed Central version
- Open Access Copy from Duke
- Link to Item
Duke Authors
Cited Authors
- Marker, DR; Zywiel, MG; Johnson, AJ; Seyler, TM; Mont, MA
Published Date
- October 2, 2010
Published In
Volume / Issue
- 11 /
Start / End Page
- 227 -
PubMed ID
- 20920316
Pubmed Central ID
- 20920316
Electronic International Standard Serial Number (EISSN)
- 1471-2474
Digital Object Identifier (DOI)
- 10.1186/1471-2474-11-227
Language
- eng
Conference Location
- England