Accuracy and safety of free-hand pedicle screw placement in cervical injury patients

Objectives: The purpose of this study was to describe the free hand method of pedicle screw placement without intraoperative imaging monitors and to evaluate the accuracy of the screw placement in quadriplegics patients. Methods: A free hand screw was inserted in the eleven cervical injury patients with quadriplegia. We studied the preoperative pedicle dimension in all the patients and assessed the clinical and radiological outcome and accuracy of the screw placement. Results: A total of 44 screws were inserted in the cervical pedicles of eleven patients. The postoperative images showed that 28 of the 44 screws had perforated the pedicles but none of them had breached the spinal canal. Among them 16 screws were grade 2 and 12 screws were grade 3. All the screws had penetrated the lateral wall. There were no neurovascular complications related to any malpositioned screw and there was no screw loosening or instrumentation failure in the patients. Conclusion: The free hand screw placement without intraoperative image guidance seems to be safe and effective method of fixation. But this technique requires sound knowledge of the cervical anatomy and experience and is useful in the places where navigation system are not available.