Minimally Invasive Percutaneous Screw Osteosynthesis for Traumatic Spondylolisthesis of the Axis

Presented at SMISS Annual Forum 2016
By Shuhei Osaki
With

Disclosures: Shuhei Osaki None

Introduction

Stable traumatic spondylolistheses of the axis (hangman’s fractures) are usually treated by a halo vest fixation. However, in some instances, such as polytrauma or conservative therapy failed cases, operative treatment may be required. 

Aims/Objectives

In this study, we describe a minimally invasive percutaneous screw osteosynthesis using intraoperative CT-based navigation for hangman’s fractures.

Methods

Eleven patients with hangman’s fractures were treated in this study. Mean age was 57.6 years. The fractures resulted from falls in 6 patients, motor-related accidents in 4 patients and a falling object in 1 patient. All fractures were evaluated by radiographs and CT imaging. Percutaneous osteosynthesis was performed in the patients with Levine-Edwards classification type I, and type II without disc injury at C2/3. Surgical procedure; a dynamic reference arc was attached to the spinous process of the axis through a small incision. After image acquisition, the fluoroscope workstation generated 3-dementional reconstructions of imaged anatomy. We made two small lateral incision and guide-wires were inserted. Cancellous lag screws were inserted over the guide-wires. Bilateral screw positions could be assessed by intra-operative 3D fluoroscopy imaging. Postoperatively, patients wore a rigid cervical collar until bone union was achieved. 

Results

Type I fractures were observed in 6 patients and type II in 5 patients. The average surgical time was 101 minutes. The average operative blood loss was 76 ml. No intraoperative complications occurred. Union was achieved in all patients. In a 72-year-old male with type II fracture, unilateral partial screw back-out was observed at the fifth postoperative week. After re-instruction of a cervical collar fixation and administration of intermittent parathyroid hormone, eventual union was achieved at the fifteenth postoperative week without screw back-out progression. 

Conclusions

Percutaneous osteosynthesis using lag screws has the benefit of less muscle disruption, maintaining a normal cervical ROM and early rehabilitation. In this study, all patients underwent surgery without complications and achieved bone union. Minimally invasive percutaneous screw fixation using intraoperative CT-based navigation seems to be a safe and useful method for the treatment of hangman’s fractures.