A fast, accurate and closed-form method for pose recognition of an intramedullary nail using a tracked C-arm

作者：Esfandiari H^*; Amiri S; Lichti D D; Anglin C

来源：International Journal of Computer Assisted Radiology and Surgery, 2016, 11(4): 621-633.

DOI：10.1007/s11548-015-1294-y

• C-arm
• Pose recognition
• IM-nail
• Pose estimation
• Radiation

The main challenge of intramedullary nail (IM-nail) fixation surgery is to achieve the X-ray shot in which the distal holes of the IM-nail appear as circles (desired view); screw insertion is then performed. Although C-arm X-ray devices are routinely used in IM-nail fixation procedures, the surgeons or radiation technologists (rad-techs) usually utilize them in a trial-and-error manner. This increases both radiation exposure and surgery time. This study addresses the problem by presenting a C-arm-based IM-nail pose recognition method.
The specific purpose of this study was to develop and validate an automated technique for identifying the current pose of the IM-nail relative to the C-arm. An accuracy assessment is performed to test the reliability of the navigation results. The algorithm starts with a sequential biplanar set of X-ray imagery (acquired from a tracked C-arm) of the distal part of an inserted IM-nail. The image-processing module then extracts features of interest, and a mathematical model incorporates them to calculate the six degree-of-freedom position and orientation parameters of the nail.
Translational accuracy was demonstrated to be better than 0.5 mm, rotational accuracy for roll and pitch to be better than and for yaw to be better than depending on the separation angle. Computation time was less than 0.5 s.
An IM-nail distal locking navigation technique is introduced in this study that leads to more accurate and faster screw placement with a lower consumption of radiation dose and a minimum number of added steps to the operation.

• 出版日期2016-4