Utilizing pre- and postoperative radiological parameters to predict surgical outcomes following untethering for tethered cord syndrome in a pediatric population

OBJECTIVE Tethered cord syndrome (TCS) can lead to significant downstream neurological deficits including gait deterioration, incontinence, and often unexplained chronic low-back pain. Surgical intervention may relieve symptoms, but there are no defined radiological parameters associated with surgical outcomes and functional status. The authors aimed to define pre- and postoperative radiological parameters for assessing surgical outcomes in TCS. METHODS The authors performed a single-center retrospective review of all pediatric patients treated for TCS between 2016 and 2021. Patient baseline characteristics and operative metrics included age, sex, level of conus, level of procedure, tethering pathology, symptoms at presentation, complications, improvement of symptoms, and reoperation rate. MRI measurements included pre- and postoperative anterior canal distance (ACD) and bending angle (BA). RESULTS Thirty-three pediatric patients were identified who underwent untethering of the spinal cord and had pre- and postoperative MRI between 2016 and 2021. The mean patient age was 5.64 ± 5.33 years. Twenty patients (60.60%) were female. Regarding the site of untethering, 31 procedures (93.93%) were performed at the lumbosacral region and 2 (6.06%) were performed at the thoracolumbar region. The conus medullaris was found above L3 in 21.21% of patients. Postoperatively, 18.18% of patients experienced complications, 48.48% showed improvement in their symptoms, and 48.48% were equivocal or had persistent symptoms. The mean preoperative ACD0 (measured from the posterior vertebral body margin [middle] to the anterior margin of the conus medullaris) was 6.15 ± 3.18 mm, the postoperative ACD0 was 2.25 ± 2.72 mm, and the average change in ACD0 was −0.90 ± 1.31 mm. The mean preoperative BA was 26.00° ± 11.56°, the mean postoperative BA was 15.92° ± 9.81°, and the average change in BA was −10.08° ± 8.80°. An optimal cutoff value for preoperative BA to predict reoperation in pediatric patients with complex TCS undergoing surgery was ≥ 31.70° (area under the curve = 0.83). CONCLUSIONS In surgically treated patients with TCS, certain preoperative radiological parameters may be important in predicting postoperative surgical outcomes; these parameters can be evaluated and reported to indicate patients at high risk for complications. Further prospective multicenter research is warranted to offer robust evidence of association of patient outcomes with preoperative radiological parameters in TCS.