Accuracy and Safety of Freehand Placement of Upper Thoracic Pedicle Screws Supported Solely by Anteroposterior, i.e., Frontal, X-Ray Fluoroscopy (C-Arm): Technical Note Including 23 Patients.

ABSTRACT

BACKGROUND: Biomechanical resistance and surgical morbidity of spinal posterior pedicle screw fixation depend on the intraosseous position of the implants. Upper thoracic pedicle screws are particularly demanding given their convergence and thin character. We present our experience as military surgeons of freehand placement of upper thoracic pedicle screws supported solely by anteroposterior, i.e., frontal x-ray fluoroscopy. METHODS: A single-center retrospective analysis was performed at Sainte-Anne Military Teaching Hospital between 2017 and 2024 of patients in whom upper thoracic pedicle screw (T1-T5) were placed with anteroposterior fluoroscopy guidance only. RESULTS: Analysis included 23 patients (mean age 59; male/female ratio 3.6; 16 traumatic lesions and 7 neoplastic lesions) in whom 15 cervicothoracic junction fixation and 8 upper thoracic spine surgeries were performed. Of 124 screws inserted (T1-T5), 85% (106/124) were graded 0 (Gertzbein-Robbins scale), whereas 14.5% (18/124) displayed some degree of misplacement (grades 1-3). All T1 screws (22/22) were accurately placed compared with 83% (20/24) of T2 screws, 88% (30/34) of T3 screws, 85% (17/20) of T4 screws, and 71% (17/24) of T5 screws, with no clinical complications. There were 3 surgical revisions (1 asymptomatic misplaced screw, 2 mechanical failures in trauma). Finally, 92.7% (51/55) of the screws inserted during working hours were accurately placed compared with 79.7% (55/69) inserted during after-hours surgeries (P = 0.039). CONCLUSIONS: Clinically, placement of upper thoracic pedicle screws supported solely by anteroposterior fluoroscopy appears to be safe. The surgical technique is simple enough to be used in settings with limited resources, such as a mobile field surgical team.