This study introduces the Navigated Orthopaedic Fixations using Ultrasound System (NOFUSS), a novel approach for surgically fixing pelvic fractures. Traditional surgical methods rely on fluoroscopy, which involves exposure to ionizing radiation and can lead to inaccuracies in screw placement. NOFUSS offers a radiation-free alternative by using ultrasound imaging and automated image analysis technologies to enable real-time navigation for iliosacral screw insertions.
In this study, surgeries were conducted on eight human cadaver specimens, with four screws inserted per specimen, to compare NOFUSS directly with conventional fluoroscopy. The results showed that NOFUSS had a median screw entry error of 8.4 mm, similar to what was achieved with fluoroscopy (7.5 mm). Importantly, when focusing on specimens that provided high-quality ultrasound images, NOFUSS demonstrated improved accuracy in screw placement compared to fluoroscopy (3.6 mm vs 8.1 mm). NOFUSS also achieved superior performance in angulation accuracy (1.4◦ vs 4.4◦).
One of the key strengths of NOFUSS is that it eliminated radiation exposure, which is a significant improvement over fluoroscopy which required an average of nearly three minutes of radiation per procedure. Additionally, NOFUSS significantly reduced the time needed for screw insertion, taking about 7 minutes and 37 seconds per screw compared to 12 minutes and 36 seconds with fluoroscopy.
A limitation of the study was that several of the cadaveric specimens used appeared to have degraded due to extended storage, which caused difficulties in US visualization. For the least degraded specimens, the breach rate was lower with US than with fluoroscopy (1 vs 2).
Overall, NOFUSS is a promising alternative to conventional methods for pelvic fracture repair. By eliminating radiation exposure, reducing screw insertion time, and providing real-time navigation, this study is the first to demonstrate the feasibility and potential benefits of an automated, ultrasound-based surgical navigation system for iliosacral screw insertions.