New-Onset Pain and Neurologic Deficit After Intraoperatively Uneventful Lumbar Spine Surgery: A Prospective Observational Case Series and Proposed Management Algorithm.

Background Postoperative pain and neurological deficit after lumbar fusion surgery are uncommon but noted and are often under-reported, which may have financial and medico-legal consequences. Objective To investigate and identify the likely causes of new-onset symptoms after lumbar spine surgery. Method This is a single-center, prospective study carried out from November 2017 to April 2020. Among the patients undergoing lumbar spine surgeries for stenosis or degenerative spondylolisthesis during the study period, all those who presented with new-onset pain or neurological deficit within the first month were included in the study. Patients with pre-existing infection, fracture, tumor, previous surgery, intraoperative events such as dural tear or root injury, and intraoperatively detected screw breach were excluded. All these patients underwent detailed clinical and radiological evaluation to ascertain the causative factor, and treatment was initiated accordingly. Results A total of 2497 surgeries were performed during the study period, among which 31 patients satisfied the inclusion criteria and were enrolled in the study. Of these, 12 patients developed neurological deficit, while 19 had only radicular pain. The etiology was identified in 14 patients in the form of screw breach, epidural hematoma, infection, fascicle herniation, recurrent disc prolapse, foraminal stenosis, and implant-related causes. The etiology could not be established in 17 patients. Conservative treatment was successful in the majority of patients; only four required surgery. Conclusion New-onset pain or neurological deficit after lumbar spine surgery, although rare, is a known complication. In spite of detailed clinical and radiological evaluation, the cause of neurological deficit or pain could not be confirmed in most cases.