Purpose of the study: Diastematomyelia is a rare spinal cord malformation defined as the presence of two separate spinal cords separated or not by an osseous, cartilaginous, or fibrous septum. Spinal malformations are almost always associated, raising difficult therapeutic challenges. Material and method: We report three cases of congenital kyphoscoliosis associated with diastematomyelia in three girls aged 12, 14 and 15 years. The diastematomyelia was dorsal in one case, thoracolumbar in one and lumbar in the third. For all three patients, the indication for surgery was progression of the scoliosis with development of neurological signs of recent progressive aggravation. Preoperative distraction with a plaster cast was pursued for several months prior to posterior instrumentation. No attempt was made to correct the cord malformation nor achieve major correction of the spinal malformation. The instrumentation bridged the thoracolumbar scoliosis in one case and stopped above the malformation in the two others. Results: The postoperative period was uneventful. There were no neurological complications. Preoperative neurological signs improved after surgery. Control radiographs showed an improvement in the deformity. At mean 6 years follow-up, these patients were not bothered in their everyday life. They had stable deformities which a globally balanced trunk. There were no signs of neurological evolution. Discussion: The therapeutic strategy for diastematomyelia remains a subject of debate. For some authors, the spinal cord should be released systematically which for the majority, this is not necessary except if spinal distraction is planned or if there is a neurological problem. If there is an indication for spinal cord release, any spurs must be removed followed by the necessary dura mater plasty. In our three patients, and in agreement with the neurosurgery team, there was no need for neurosurgical release. The recent development of neurological deficits was explained by the important kyphosis rather by the intramedullary anomaly. Our therapeutic strategy thus focused on treatment of the scoliosis. This enabled us to stabilise the spine, protecting these patients from worsening neurological involvement and enabling good functional outcome. The zone of the malformation was not instrumented in all cases because the posterior arcs were deformed, but also to avoid compromising any future neurosurgical intervention

Objective: To study the long term operative and non-operative outcome in patients with diastematomyelia (DM). Design: A prospectively acquired database of all spinal patients seen jointly by the senior authors (JKW, JLF), was searched for patients with DM. Their notes and the database were then reviewed. Subjects: Thirty-six patients were identified; twenty-one (58%) had associated scoliosis. There were 60 associated abnormalities in the 36 patients, most common being ten (27%) with leg length inequality. Twelve patients (33%) had no radiological bony abnormality. Twenty-four (66%) had neurosurgery, eleven (31%) untethering of filum alone and eleven (31%) with removal of a spur and closure of the DM as well. Nineteen (53%) underwent some sort of neuraxial shortening scoliosis correction/surgery. Twenty-eight (78%) were deemed to have a normal/independent neurological outcome, seventeen (61%) having neurosurgery and twelve (43%) scoliosis surgery. Conclusions: Patients with DM have been followed up for many years. Good neurological outcomes can be anticipated in cases with untethering and with scoliosis correction alone. This series raises the question as to whether any unthethering procedure is necessary in these cases when neuraxial shortening is carried out for scoliosis cases

Statement of purpose: To profile the neurological lesions associated with scoliosis, evaluate the role of preoperative MRI and determine the proportion of patients requiring surgery for an intradural lesion. Methods: The records of patients undergoing surgery to treat scoliosis over a 5 year period were reviewed as part of this retrospective single centre study. Results: 1926 patients underwent 2714 procedures to treat scoliosis. 45 patients from this cohort were referred for an opinion regarding at least one of the following neural axis abnormalities: Syrinx (47%); Chiari malformation and cerebellar ectopia (40%); tethered cord (13%); persistent central canal (9%); diastematomyelia (7%); neurofibromata (7%); syndromes other than neurofibromatosis (7%); tumours (4%) and vascular lesions (2%). 18 patients underwent surgery to treat a neural axis lesion: Foramen magnum decompression (12); cord untethering (4) and the surgical treatment of diastematomyelia (2). Conclusions: The authors believe their series to be the largest to date. Preoperative MRI scans should extend from the cranio-cervical junction to the sacrum, reflecting the potential locations of neural axis lesions. Radiologists present at units treating scoliosis should be able to identify both commonly occurring lesions such syrinx and intradural pathology. A significant proportion of patients required surgery to treat their neural axis lesions. Centres treating patients with scoliosis should therefore have the necessary facilities to treat not only scoliosis but also its associated intradural spinal lesions. Ethics approval: None Audit. Interest Statement: None