A new study published in the Journal of Spinal Disorders and Techniques examines free-hand screw placement accuracy using a new method that includes localized entry points.
The surgeons used a simple geometric method of localization of entry points designed to improve anatomic orientation, according to the study abstract. There were 85 patients included in the study, and 410 screws included.
The researchers found:
1. There were 20 mal-positioned screws.
2. Overall accuracy was 95.12 percent.
3. The L1 level had the highest breach rate at 21.43 percent.
4. The difference between the L1 breach rate and breach rate at other levels was statistically significant.
5. There were two screws in two patients that were symptomatic, causing radicular pain. Both patients underwent successful revision surgery.
"The proposed method of PS placement is safe and reliable for all levels from L2 to S1, with the accuracy similar to image-guided navigation systems," concluded the study authors.