Posterior pedicle fixation with polyaxial screws and rods for combined fractures of the atlas and axis

Abstract

Objective To investigate the clinical outcomes of posterior pedicle fixation (C1-C2 pedicle fixation or C1-C3 pedicle fixation) with polyaxial screws and rods for combined fractures of the atlas and axis. Methods From August 2007 to May 2014, we treated 24 patients with combined fractures of the atlas and axis using posterior pedicle fixation with polyaxial screws and rods. There were 10 cases of C1-odontoid Type Ⅱfracture, 4 cases of C1-miscellaneous C2 fracture, 4 cases of C1-odontoid Type Ⅲ fracture, and 6 cases of C1-hangman's fracture. Posterior C1-C2 pedicle fixation was adopted in 16 cases and posterior C1-C3 pedicle fix-ation in 8 cases to stabilize the atlas and axis. The clinical and radiological outcomes were evaluated using to the visual analogue scale (VAS), Frankel grading, neck disability index(NDI) and Japanese Orthopaedic Associa-tion (JOA) scores. Graft fusion and operative complications were documented. Results The operative time ranged from 90 to 170 min (mean, 123 min); the blood loss ranged from 290 to 750 mL (mean, 427 mL). The patients were followed up for 15 to 45 months (mean, 27 months). Bony fusion was achieved within 9 months (mean, 4.7 months). The Frankel grading was improved in all the 10 patients with neural deficits. The pre-operative VAS, NDI and JOA scores (6.8±1.0, 41.4±1.6 and 8.6±1.0, respectively) were significantly improved to 1.6±0.7, 11.2±1.9 and 15.3±1.2, respectively (P<0.05). The rates of JOA improvement averaged 78.5%, ranging from 60.0% to 87.5%. One patient suffered hemorrhage from a pseudoaneurysm of the injured vertebral artery 2 days after surgery. No such complications happened as implant failure, fracture nonunion, spinal cord injury, cerebrospinal fluid leakage or wound infection. Conclusions Posterior pedicle fixation with polyaxial screws and rods is an effective and relatively safe technique for combined fractures of the atlas and axis, because it can reduce the fracture, restore cervical sequence, fixate firmly, and lead to a high rate of graft fusion. Digital subtraction angiography and interventional embolization is feasible and effective if hemorrhage from a pseudoaneurysm occurs due to vertebral artery injury postoperatively. Key words: Atlas; Axis; Fractures, bone; Fracture fixation, internal; Pedicle screw fixation