Supplementary Material for: Long-Segment Type 1 Split Cord Malformation with Two-Level Split Cord Malformation and a Single Dural Sac at the Lower Split

Objective and Importance: Two-level bony spurs are rare and also a very long segment of bony spur is very rare. Bony spur with a single dural covering is not reported in the literature. Here, we report a case of prophylactic surgery performed on a patient with a bony spur with a single dural covering who showed a good postoperative outcome. This case highlights the importance of prophylactic surgery in such patients to avoid cord injuries. Clinical Presentation: Since birth a 1-year-old child had had a tuft of hair at the dorsal (D6 and D7) region. The patient was examined and found to have scoliosis with convexity towards the right. There was no neurological deficit. MRI and CT spine scans showed 2-level type 1 split cord malformation (SCM) and there was a low-lying conus at the L3–4 level. Intervention: The patient was operated on at the age of 1 year and 2 separate bony septae were observed. The upper one extended from D5 to D9 and the lower one was at the D11 level. The bony spurs were excised. The filum was sectioned at the L4–5 level by a separate incision. The patient had a good postoperative recovery. Conclusion: With meticulous planning and careful surgery, prophylactic surgery can have a very good outcome in long-segment and two-level type 1 SCM.