Surgical safety of cervical pedicle screw placement with orthopaedic surgery robot system / 中华骨科杂志

ABSTRACT

Objective:To evaluate the accuracy and safety of cervical pedicle screw (CPS) placement under orthopaedic robot navigation system guidance.Methods:From March 2019 to February 2021, the data of 33 patients (19 males and 14 females, aged from 26 to 75 years, with an average age of 50.5 years) treated with pedicle screw fixation with the assistance of orthopaedic surgery robot through the posterior cervical spine were retrospectively analyzed. In clinical diagnosis, there was upper cervical fracture with instability in 14 patients (fracture nonunion in 2 patients), upper & subaxial cervical fracture in 1 patient, cervical spinal cord injury with spinal stenosis in 2 patients, cervical spinal stenosis in 9 patients, occipitocervical deformity in 2 patients, post-operative revision of cervical spondylosis in 2 patients, cervical intraspinal tumor in 3 patients. A total of 151 CPSs were inserted in C 1-C 7 using robot navigation system based on intraoperative three-dimensional C-arm fluoroscopy to assist in screw placement in posterior cervical surgery. Among them, 74 screws were implanted into upper cervical spine; 77 screws were implanted in the lower cervical spine. CT was used to obtain image data within 7 days after operation, and Neo classification was used to evaluate the accuracy of cervical pedicle screw placement. The patients were followed up for 2 weeks to observe the clinical symptoms and signs, and to determine whether there were surgical complications such as nerve and blood vessel injury and incision infection. Results:According to Neo classification, 91.4% (138/151) screws were completely contained in the pedicle without breaking through the pedicle cortex (grade 0). Among them, the accuracy of C 1 screws was 97.1% (34/35), C 2 screws was 92.3% (36/39), C 3 screws was 88.2% (15/17), C 4 screws was 71.4% (10/14), C 5 screws was 85.7% (12/14), C 6 screws was 93.3% (14/15), C 7 screws was 100.0% (17/17). The screw accuracy was highest in C 7, the lowest in C 4. The Kruskal-Wallis H test was performed on the accuracy of screw placement in different cervical level, and the results showed that there was no statistical difference (χ 2=1.31, P=0.971). However, a total of 13 screws were found to perforate the cortex of pedicle, although any neural or vascular complications associated with CPS placement were not encountered. Among them, 9 screws were found to perforate laterally, and 4 screws were found to perforate medially. No postoperative incision infection occurred in all cases. Conclusion:The safety of CPS placement can be effectively guaranteed with the assistance of the orthopaedic robot system.