Fiducial-free 2D/3D registration of the proximal femur for robot-assisted femoroplasty

Cong Gao, Robert B. Grupp, Mathias Unberath, Russell H. Taylor, Mehran Armand

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations


Femroplasty is a proposed therapeutic method for preventing osteoporotic hip fractures in elderly. Patientspecific femoroplasty based on a preoperative plan, however, requires accurate 3D pose estimation of the proximal femur. Prior work on the development of a navigation system required the attachment of an optical fiducial to the osteoporotic femur. In this paper, we propose a fiducial-free 2D/3D registration pipeline, which uses the pelvis to initialize the femur registration. Intraoperative X-ray images are taken from multiple views to perform compound object registration. The proposed method was tested through a comprehensive simulation study. Performance was evaluated on the femoral head center frame registration error and the injection entry point error on the trochanter surface. The algorithm achieved a mean accuracy of 2.75 ± 2.19 mm for the entry point ℓ2 distance and 0.81 ± 0.58° for the planning path direction, which is sufficiently accurate for robotic drill positioning.

Original languageEnglish (US)
Title of host publicationMedical Imaging 2020
Subtitle of host publicationImage-Guided Procedures, Robotic Interventions, and Modeling
EditorsBaowei Fei, Cristian A. Linte
ISBN (Electronic)9781510633971
StatePublished - 2020
EventMedical Imaging 2020: Image-Guided Procedures, Robotic Interventions, and Modeling - Houston, United States
Duration: Feb 16 2020Feb 19 2020

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceMedical Imaging 2020: Image-Guided Procedures, Robotic Interventions, and Modeling
Country/TerritoryUnited States


  • 2D/3D Registration
  • Femoroplasty
  • Femur Registration
  • X-ray Navigation

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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