PURPOSE: The purpose of this study was to compare different methods of evaluating the version of a metallic acetabular cup from plain radiographs and to compare them regarding their accuracy, inter- and intra-observer reliability. METHODS: Conventional anterior-posterior radiographs were taken of a phantom-model at different defined ante- and retroversion angles of the acetabular cup. The version angles of the acetabular cup were derived according to four different established methods from the radiographs by five independent examiners. RESULTS: We were able to determine the radiographic version with the greatest accuracy according to a modified technique of Pettersson et al. Furthermore, we found the highest intra- and inter-observer reliability using this technique. CONCLUSIONS: A modified technique of Pettersson et al. broadens the spectrum of applicability for the radiographic evaluation of the version angle of metal-backed acetabular cups in comparison to the originally introduced method. In clinical practice, however, the significance of deriving the cup position from standard radiographs should not be over-estimated and therefore a computed tomography should be performed in certain critical cases.
PURPOSE: The purpose of this study was to compare different methods of evaluating the version of a metallic acetabular cup from plain radiographs and to compare them regarding their accuracy, inter- and intra-observer reliability. METHODS: Conventional anterior-posterior radiographs were taken of a phantom-model at different defined ante- and retroversion angles of the acetabular cup. The version angles of the acetabular cup were derived according to four different established methods from the radiographs by five independent examiners. RESULTS: We were able to determine the radiographic version with the greatest accuracy according to a modified technique of Pettersson et al. Furthermore, we found the highest intra- and inter-observer reliability using this technique. CONCLUSIONS: A modified technique of Pettersson et al. broadens the spectrum of applicability for the radiographic evaluation of the version angle of metal-backed acetabular cups in comparison to the originally introduced method. In clinical practice, however, the significance of deriving the cup position from standard radiographs should not be over-estimated and therefore a computed tomography should be performed in certain critical cases.
Authors: Bernard Ghelman; Christopher K Kepler; Stephen Lyman; Alejandro González Della Valle Journal: Clin Orthop Relat Res Date: 2009-03-10 Impact factor: 4.176
Authors: Henrik Olivecrona; Lars Weidenhielm; Lotta Olivecrona; Mats O Beckman; André Stark; Marilyn E Noz; Gerald Q Maguire; Michael P Zeleznik; Lars Svensson; Torbjörn Jonson Journal: Acta Orthop Scand Date: 2004-06