Regrowth of diastematomyelic bone spur after extradural resection. Case report.

Complete regrowth of a diastematomyelic bone septum producing progressive neurological deficits was found in a 15-year-old boy who had a previous extradural resection of a similar bone spur with the dural sleeve left untouched. This case and two similar cases in the literature documenting continued neurological deterioration after extradural removal of septum emphasize the need for resection of the dural sleeve along with the bone septum if adequate relief of tethering is expected. The capability of the septum to regenerate may be due to the persistence of residual mesenchymal cells associated with the embryogenesis of the midline septum.