Treatment of pelvic ring fractures: Percutaneous computer assisted iliosacral screwing

Abstract

Abstract. This paper describes the development and preliminary testing of an image-guided system for the placement of iliosacral screws to stabilize pelvic ring fractures percutaneously, with the aim of decreasing the incidence of surgical complications and increasing the accuracy of screw placement. Pre-operative planning of screw trajectories is performed on a 3D model of the pelvis constructed from CT scans. During surgery, a 6D optical localizer is used to track the positions and orientations of an ultrasound probe, a surgical drill and a reference frame fixed to the posterior iliac crest. Registration of the pre-operative model with curves segmented from the ultrasound scans is performed using a surface-based algorithm. The drill tip and axis are displayed relative to the desired screw trajectories in real time. The accuracy of the system has been verified in four cadaver specimens by comparing actual screw trajectories to the desired trajectories and by measuring the distance from each screw to important anatomical landmarks on post-operative CT scans. All screws were considered to be in correct position.

A Fully Automated Method for the Delineation of Osseous Interface in Ultrasound Images

“…The processing of large datasets such as Patient 3 takes about 4 minutes whereas it would take more than 30 minutes in the case of a manual delineation (according to [1]). …”

“…The usual way to acquire it is to register pre-operative data with intra-operative data. For the last years, the use of ultrasound imaging as intra-operative imaging has significantly increased ( [1,2,3,4]) because such imaging investigations are inexpensive and riskless ; and using 6D localized ultrasound probe makes it possible to reconstruct the 3D shape of a structure after its delineation. The extraction of structures from ultrasound data appears to be a delicate key point in CAOS.…”

FRACAS: A system for computer‐aided image‐guided long bone fracture surgery

“…Examples include total hip replacement systems for canal milling (ROBODOC 36 ) and acetabular cup placement (HipNav 35 ); systems for total knee arthroplasty 7 and total knee replacement 25 ; and ACROBOT 5 ; and systems for pedicle screw insertion, 22,27,28 illiosacral screw placement, 10 pelvic osteotomies, 21 and pelvic fracture reduction. 4 The strength of CTbased systems is that they produce the most accurate 3D geometric models.…”

An Information Fusion Method for the Automatic Delineation of the Bone-Soft Tissues Interface in Ultrasound Images

“…• The proposed method is also sufficiently fast to be used during the intra-operative stage of a CAOS : the time needed to delineate one image is less than 4 s. The processing of large datasets such as Patient 3 takes about 4 minutes (on a standard PC, Pentium III-800Mhz) whereas it took more than 30 minutes in the case of a manual delineation (according to [20]). …”