Are component positioning and prosthesis size associated with hip resurfacing failure?

Marker, David R

Zywiel, Michael G

Johnson, Aaron J

Seyler, Thorsten M

Mont, Michael A

England

2015-08-12T18:12:13Z

2015-08-18T15:51:34Z

2010-10-02

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.

http://www.ncbi.nlm.nih.gov/pubmed/20920316

1471-2474-11-227

1471-2474

https://hdl.handle.net/10161/10410

eng

Springer Science and Business Media LLC

BMC Musculoskelet Disord

10.1186/1471-2474-11-227

http://hdl.handle.net/10161/10375

10161/10375

Adolescent

Adult

Aged

Arthroplasty, Replacement, Hip

Equipment Failure Analysis

Female

Hip Prosthesis

Humans

Male

Middle Aged

Prosthesis Failure

Retrospective Studies

Young Adult

Are component positioning and prosthesis size associated with hip resurfacing failure?

Journal article

Seyler, Thorsten M|0000-0003-1157-132X

http://www.ncbi.nlm.nih.gov/pubmed/20920316

227

Clinical Science Departments

Duke

Orthopaedics

School of Medicine

Published online

11