Automated assessment of polyethylene wear in cemented acetabular components using anteroposterior radiographs of total hip replacements

作者：Kerrigan C Stuart; McKenna Stephen J^*; Ricketts Ian W; Wigderowitz Carlos

来源：Computerized Medical Imaging and Graphics, 2008, 32(3): 221-238.

DOI：10.1016/j.coin1)inediniig.2007.12.002

• acetabular wear
• total hip replacement
• radiographic analysis
• robust ellipse fitting
• eccentricity error

Polyethylene wear in the acetabular components of hip prostheses is implicated in loosening and failure. Radiographic measurement of wear is used to identify patients at risk and to assess prosthesis designs. This paper focuses on analysis of prostheses with cemented acetabular cups from anteroposterior (AP) radiographs. The articular Surface of the femoral head and the acetabular rim marker are modelled as spherical and circular respectively, resulting in elliptical image projections. Methods for automatically localising these structures in radiographs are presented using robust ellipse fitting and various error functions. Special attention is paid to the acetabular market since this often projects as a highly eccentric ellipse. Robust fitting enables Successful localisation in the presence of clutter without the need for user interaction. Finally, the use of these ellipses as reference structures for wear estimation is investigated and the effect of eccentricity errors is highlighted.

• 出版日期2008-4