Computer aided surgery : official journal of the International Society for Computer Aided Surgery
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Comput. Aided Surg. · Jan 2012
The accuracy of 3D image navigation with a cutaneously fixed dynamic reference frame in minimally invasive transforaminal lumbar interbody fusion.
In contrast to preoperative image-based 3D navigation systems, which require surgeon-dependent registration, an intraoperative cone-beam computed tomography (cb-CT) image-based 3D navigation system allows automatic registration during the acquisition of 3D images intraoperatively. Thus, the need for spinal exposure for point matching is obviated, making a cb-CT image-based navigation system ideal for use in minimally invasive spinal procedures. Conventionally, the dynamic reference frame (DRF) is mounted to an adjacent spinous process or iliac bone through a separate incision. However, the close proximity of the DRF to the surgical area may result in its interfering with the surgical procedure or causing streak artifacts on the navigation images. Cutaneous placement of the DRF overlying the sacral hiatus is one possible solution to these problems, but such a placement does not provide a solid bony fixation point and is distant from the surgical area, both of which factors may hinder the accuracy of the navigation. The purpose of this study was to evaluate the accuracy of a novel idea for DRF placement in a series of mini-open transforaminal lumbar interbody fusion (TLIF) procedures performed with intraoperative cb-CT image-based 3D navigation. ⋯ A cutaneously mounted DRF overlying the sacral hiatus provides accuracy in intraoperative 3D image guided navigation for mini-open TLIF that is comparable to that obtained in other reported series using a fixed bony attachment point for the DRF.
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Comput. Aided Surg. · Jan 2012
Comparative StudyComparison of robot-assisted and conventional total knee arthroplasty: a controlled cadaver study using multiparameter quantitative three-dimensional CT assessment of alignment.
A functional total knee replacement has to be well aligned, which implies that it should lie along the mechanical axis and in the correct axial and rotational planes. Incorrect alignment will lead to abnormal wear, early mechanical loosening, and patellofemoral problems. There has been increased interest of late in total knee arthroplasty with robotic assistance. This study was conducted to determine whether robot-assisted total knee arthroplasty is superior to the conventional surgical method with regard to the precision of implant positioning. ⋯ Robot-assisted total knee arthroplasty showed excellent precision in the sagittal and coronal planes of the 3D CT scan. In particular, the robot-assisted technique showed better accuracy in femoral rotational alignment compared to the conventional surgery, despite the fact that the surgeons who performed the operations were more experienced and familiar with the conventional method than with robot-assisted surgery. It can thus be concluded that robot-assisted total knee arthroplasty is superior to conventional total knee arthroplasty.
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Comput. Aided Surg. · Jan 2011
Registration of CT to 3D ultrasound using near-field fiducial localization: A feasibility study.
Registration of ultrasound to computed tomography (CT) images is used in several image-guided procedures, including laparoscopic surgery and radiation therapy. Conventional approaches use an external tracker calibrated to the ultrasound transducer and CT system, but several calibration steps are required. Registration can also be performed by aligning image features between modalities, but differences in feature depiction make matching difficult and initial approximate alignment is often needed. Registration using fiducials is a simpler approach but is limited by the need to implant fiducials in the anatomical region of interest so they are visible to both ultrasound and CT. This paper investigates the feasibility of using fiducials near the skin surface, and whether such fiducials can be sufficiently localized in the very near field of a 3D ultrasound transducer without significantly degrading image quality. This approach can also be used as an initialization step for feature-based registration techniques. ⋯ The small loss of image quality from the fiducial stand-off pad and the minimal inconvenience of using the pad at the time of the CT scan may be a worthwhile trade-off for purposes of registration since the pad provides a registration accuracy of several millimeters while still allowing subsequent feature-based registration. Future research will focus on using the registration from the fiducial stand-off pad for deformable feature-based registration of 3D ultrasound to CT for tumor localization in renal surgery.
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Comput. Aided Surg. · Jan 2011
Review Comparative StudyRobotics in urological surgery: review of current status and maneuverability, and comparison of robot-assisted and traditional laparoscopy.
To assess the current state of robot-assisted urological surgery, the literature concerning surgical robotic systems, surgical telemanipulators and laparoscopic systems was reviewed. Aspects of these systems pertaining to maneuverability were evaluated, with a view to quantifying their stability and locomotive properties and thereby determining their suitability for use in assisted laparoscopic procedures, particularly robot-assisted laparoscopic urological surgery. The degree of maneuverability and versatility of a robotic system determine its utility in the operating room, and the newer-generation surgical robotic systems have been found to possess a higher degree of maneuverability than older class 1 and class 2 systems. It is now clearly established that robots have an important place in the urologist's armamentarium for minimally invasive surgery; however, the long-term outcomes of several urological procedures (other than robot-assisted radical prostatectomy) performed with the da Vinci surgical robotic system have yet to be evaluated.
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Comput. Aided Surg. · Jan 2009
Randomized Controlled TrialComputer assisted LISS plate placement: an in vitro study.
A laboratory study was conducted to compare the accuracy with which a LISS plate could be placed on the distal metaphysis of a model femur using both a fluoroscopy-based computer assisted technique and the conventional fluoroscopic technique. A significant difference was found between outcomes with the two approaches with respect to the maximum distance from the plate to the diaphysis of the bone, but there was no significant difference in the maximum distance to the condylar area. There was also no difference with respect to the number of holes that required re-drilling for adjustment of the plate placement or screws with poor purchase in bone. There were, however, significant differences between the two techniques in terms of duration of the procedure and radiation exposure.