The removal of a transdural pedicle screw placed for thoracolumbar spine fracture

Study Design. This report describes the method of removal of a pedicle screw that had been misplaced through the thecal sac and the cauda equina instead of its proper location within the pedicle. Objectives. A patient who previously had undergone placement of pedicle screws and Roy-Camille plates for fixation of L1 burst fracture presented to the authors with neurologic deficits and a cerebrospinal fluid leak. Computed tomography myelogram and surgical findings demonstrated misplacement of three of the screws, one of which was placed through the dura with resulting impingement of nerve roots within the thecal sac. Summary of Background Data. Removal of the screws was required for neural decompression and resolution of the cerebrospinal fluid leak. Methods. The patient underwent laminectomy to expose the screw and primary durotomy to include the entry point of the screw. This technique allowed safe removal under direct vision, with direct protection of the nerve roots. A subsequent anterior fusion procedure was performed. Results. The patient regained full neurologic function, and his cerebrospinal fluid leak ceased. At 2-year follow-up evaluation, he describes only mild, occasional back pain. Conclusions. Penetration of the dura and injury to the neural elements can occur when pedicle screw instrumentation is used. Removal of the screw under these circumstances may cause additional neurologic injury. Durotomy and direct visualization of the neural elements in this case was a valuable adjunct to safe removal of the screw.