Model-based Roentgen stereophotogrammetry of orthopaedic implants

摘要: Attaching tantalum markers to prostheses for Roentgen stereophotogrammetry (RSA) may be difficult and is sometimes even impossible. In this study, a model-based RSA method that avoids the attachment of presented validated. This uses triangulated surface model implant. A projected contour calculated matched onto detected actual implant in radiograph. The difference between two contours minimized by variation position orientation model. When minimal found, an optimal has been obtained. was validated means phantom experiment. Three prosthesis components were used experiment: femoral tibial component Interax total knee (Stryker Howmedica Osteonics Corp., Rutherfort, USA) Profix (Smith & Nephew, Memphis, USA). For accuracy lower than traditional RSA. components, significant dimensional tolerances found probably caused casting process manual polishing surfaces. largest standard deviation any translation 0.19 mm rotation it 0.528. had no large tolerances, 0.22 0.228. From study we conclude current sensitive Research now beingconducted make less thereby improvingits accuracy. # 2001 Elsevier Science Ltd. All rights reserved.