Three-dimensional assessment of pedicular screws in thoracic and lumbar fractures using free-hand technique

Introduction
Several sophisticated image-guided modalities have been developed to improve the accuracy of screw placement; however, such modalities may increase healthcare costs and radiation exposure to the patient, and the clinical efficacy compared with traditional techniques may be questionable. Globally, the free-hand technique of pedicle screw placement was found to be a reliable and safe method with low rates of complications and to be potentially more cost-effective than other sophisticated techniques in treating several spinal disorders.
Aim
The aim of this work was to assess the accuracy and safety of free-hand pedicle screw placement in thoracic and lumbar fractures using minimal image exposure.
Materials and methods
This is a prospective radiographic review of thoracic and lumbar pedicle screws inserted in patients suffering from unstable fractures. All of the procedures were performed by a single consultant spine surgeon. Screws were inserted at one side and then intraoperative lateral imaging was used to check the level and verify the position of the screws. The same procedure was repeated on the other side. The vertebral bodies were divided into three equidistant horizontal zones (A, B, and C). Positioning of the screw tips was regarded as ideal when located in zones A and B. Multislice computed tomography was used to assess the accuracy.
Results
There were 669 pedicle screws inserted in 88 consecutive cases from T3 to L5, with a mean of 7.6 screws. The overall number of misplaced screws was nine (1.3%). Intraoperative revision was made in 16 (seven cases, 2.4%) screws. No intraoperative or immediate postoperative complication occurred due to screw placement.
Conclusion
Minimal revision rate was noticed, and only two lateral images were needed in most of the cases. This is quite important in developing countries, where an image intensifier serves more than one room.