A new study published in Spine examines the accuracy and safety of pedicle screw placement using CT for patients undergoing adolescent idiopathic scoliosis correction surgery.
The study authors examined screw placements for 140 patients with the CT technology. The researchers used CT to assess perforations according to Rao et al classification. There were 2,020 pedicle screw placements in the study.
The study authors found:
1. There was 20.3 percent perforation rate, as 410 screws perforated. The perforation levels were:
• Grade 1: 8.2 percent
• Grade 2: 2.9 percent
• Grade 3: 9.2 percent
2. Lateral perforation was most common in the thoracic region, due to surgeons using extrapedicular screws. Without the lateral perforations, the perforation rate was:
• Overall: 6.4 percent
• Grade 2: 2.4 percent
• Grade 3: 0.8 percent
3. Two symptomatic left medial grade 2 perforations occurred; one of the perforations was at T12 and created iliac crest numbness while the other was at L2 and manifested with radicular pain.
4. Six anterior perforations occurred next to the right lung while for were next to the aorta. Two of the perforations were next to the esophagus and another was next to the trachea.
5. The study authors concluded, "The rate of symptomatic screw perforation leading to radicular symptoms was 0.1 percent. There was no spinal cord, aortic, esophageal or lung injuries caused by malpositioned screws in this study."