Authors: Daniel Munger, MD
Early detection and treatment of tethered cord as the underlying etiology of scoliosis can mitigate curve progression, neurologic decline and pain. We hypothesize that patients with both scoliosis and tethered cord represent a unique clinical entity. Our goal was to describe the clinical characteristics of patients with both scoliosis and tethered cord in order to identify clinical factors that might aid in earlier identification, which could ultimately save children from larger fusion surgeries in the future.Methods: We conducted a retrospective review of patients with scoliosis who underwent filum lysis at our institution from 2015-2019. Demographic data, presenting symptoms, pre and postoperative Cobb angle, surgical management, outcomes and complication rates were collected and tabulated.
We identified 23 patients previously deemed to have idiopathic scoliosis who underwent filum lysis. Mean age was 11.5 years and mean follow-up 8.1 months. The most common presenting symptoms included back pain (57%), leg pain (30%) and leg length discrepancy or asymmetry (39%). A syrinx was identified in 39% of patients and conus terminating at or below L2 in 65%. Eighty-five percent experienced improvement or resolution of back pain after filum lysis. The mean Cobb angle was 30.5 preoperatively and 37.5 postoperatively. One patient (4%) was found to have significant scoliosis improvement on follow-up. Fifty-seven percent showed no difference in curve and 22% had worsening. Five patients had insufficient imaging. Nine ultimately underwent scoliosis correction surgery following untethering.
Patients with idiopathic scoliosis do not appear to present with typical tethering symptoms (i.e. bowel/bladder dysfunction). Patients with simultaneous scoliosis and tethered cord present with pain out of proportion to their degree of curvature. Back/leg pain specifically should prompt MRI imaging in this population and thus could lead to earlier detection and referral. Also, a low-lying conus or syrinx in a patient with idiopathic scoliosis should prompt neurosurgery referral.