With the promising potential of improving outcomes, new technologies weave into the healthcare industry. But as costs continue to rise, healthcare professionals may want to consider if the amount of improvement resulting from new technology outweighs the associated pitfalls.
Neurosurgeon Srinivas Prasad, MD, MS, of the department of neurological and orthopedic surgery at Thomas Jefferson University in Philadelphia, presented on pedicle screw accuracy measurements at the North American Spine Society annual meeting in Chicago.
He explained most of the data on navigation systems in spine involves pedicle screws. Pedicle screw accuracy focuses mainly on anatomic accuracy, with various techniques to characterize accuracy.
"We all know that accuracy can affect a number of things — fusion rate, adjacent level disease, deformity correction or preservation," said Dr. Prasad. "So there are real implications, I think, to the pedicle screw accuracy."
Dr. Prasad cited Stanley Gerzbein, MD, and Stephen Robbins, MDI, as setting the precedent for measuring pedicle screw accuracy with their 1990 paper. The study was the first to define accuracy measurement in vivo; it focused on canal encroachment and is the most widely-accepted system for pedicle screw accuracy today.
A more recent paper by Victor Kosmopoulos, PhD, and Constantin Schizas, MD, PD, FRCS, published in 2007, was a meta-analysis of 130 studies, looking at with and without navigation accuracy rates.
Dr. Prasad said the results of this study, which reported 90.3 percent accuracy without navigation and 95.2 percent accuracy with navigation as "reasonable numbers to take home."
The researchers took a step further and analyzed the various ways to measure accuracy. "There are 35 different assessment methods, showing how heterogeneous this space is," said Dr. Prasad.
Digging through these assessment methods, Dr. Prasad identified the dichotomous method and the Gertzbein-Robbins method as the two most common accuracy measurement styles. While the dichotomous method focuses on "breach or no breach" analyses, the Gertzbein-Robbins method relies on two millimeter increments. The researchers of the study didn't recommend either method.
"We had a discussion about reimagining this in the scope of new procedures and what we know now," said Dr. Prasad. He presented several more recent papers on alternative methods for measuring pedicle screw accuracy.
"What's evolved in the last five or 10 years is that navigation is not all the same," said Dr. Prasad.
The 2014 meta-study analysis led by Alexander Mason, MD, looked at conventional fluoroscopy, two-dimensional fluoroscopic navigation and three-dimensional navigation, with a dichotomous accuracy method. The conventional accuracy was 68.1 percent, the two-dimensional fluoroscopic navigation accuracy was 84.3 percent and the three-dimensional navigation accuracy was 95.5 percent. These findings support the idea that navigation improves accuracy.
After reviewing the major studies on measuring pedicle screw accuracy, Dr. Prasad addressed the issue of the impact of navigation on radiation exposure.
"There's not a tremendous amount of data on this," said Dr. Prasad, referencing a Jimmy Villard, MD, et. al 2014 randomized trial. "There is almost a tenfold increase in radiation exposure if you do everything fluoro-based."
Wrapping up, Dr. Prasad addressed the learning curve that presents an obstacle to adopting navigation.
"I think a lot of people have abandoned [navigation] when they first start using it because it changes your workflow," he said. "…With navigation, it has a bit of a leveling the playing field effect." Navigation allowed a more inexperienced surgeon to perform with a comparable accuracy to a more experienced surgeon, based on the 2010 Bai, et al. study.
Dr. Prasad concludes with the idea that although meta-analyses are structurally flawed, their findings point to the conclusion that pedicle screw accuracy is better with navigation as opposed to "conventional" techniques.
"In conclusion, I would say that intraoperative navigation systems certainly have gotten better," said Dr. Prasad. "It appears that as the technology has gotten better, the accuracy has followed." Further, navigation may serve surgeons better when dealing with the thoracic spine, and the systems seem to reduce radiation exposure.
"There is more research to be done in terms of correlating all of this data to clinical significance," concludes Dr. Prasad.