Progressive posttraumatic myelomalacic myelopathy: treatment with untethering and expansive duraplasty

Abstract

Patients with progressive posttraumatic myelomalacic myelopathy (PPMM), or tethered cord syndrome, present with symptoms and signs similar to those observed in case of progressive posttraumatic cystic myelopathy, that is, sensorimotor function deterioration, local and/or radicular pain, increased spasticity, increased autonomic dysreflexia, and sphincter dysfunction. The authors investigated surgical outcomes of untethering combined with expansive duraplasty. Forty patients with PPMM who presented with functional deterioration underwent untethering of the spinal cord and nerve roots with an expansive duraplasty. Meticulous dissections of adhesions on the dorsal and lateral aspects of the spinal cord and nerve roots were performed. Intraoperative ultrasonography was used to detect the presence of a confluent cyst and to assess the success of untethering. After surgery, the patients were treated using a protocol that involved frequent turning for 48 hours and subsequently mobilization. Preoperative magnetic resonance (MR) imaging, with and without administration of a contrast agent, was obtained in all patients, except one patient who underwent immediate and delayed computerized tomography (CT) myelography. The mean follow-up period was 3 years (range 20-57 months) for the 36 patients available for follow-up review. Spinal cord tethering was observed in all patients preoperatively. Trauma was the most common cause of this pathology, accounting for 31 of the 40 cases. Preoperative MR imaging did not demonstrate tumor recurrence in the group of five patients who had undergone an initial operation for tumor excision. The interval between the causative event and the operation was less than 5 years in half of the patients (20 of 40), with the longest interval lasting up to 37 years. Motor function deterioration was the most frequent manifestation; it was present in 31 of 40 patients. Improvements in motor function, autonomic dysreflexia, pain, sphincter dysfunction, and sensory function were found during the most recent follow-up examination in 79%, 75%, 62%, 50%, and 43% of the patients, respectively. Two patients experienced retethering of the spinal cord and one underwent a second operation. Surgical untethering and expansive duraplasty, followed by postoperative position rotation to avoid retethering, provide symptomatic relief for patients with PPMM.

Perilesional myeloradiculopathy with tethered cord in post-traumatic spinal cord injury

“…5 Because arachnoiditis is a form of healing, the possibility to prevent postoperative arachnoiditis is poor. The prevention of postoperative re-tethering could be based upon the quality of the expansile duraplasty, which must be tacked up to the paraspinal muscles or spinous processes, as well as the absence of a subarachnoid haemorrhage.…”

“…The prevention of postoperative re-tethering could be based upon the quality of the expansile duraplasty, which must be tacked up to the paraspinal muscles or spinous processes, as well as the absence of a subarachnoid haemorrhage. Lee et al 5 also advocated the frequent turning of the patient from side-to-side into the prone position in the postoperative period, which could prevent the deposit of sediment in the recumbent position and the creation of a new tethering scar. Nevertheless, preventing re-tethering after surgery of a tethered cord remains poorly controlled.…”

“…[1][2][3][4][5][6][7] Cord tethering, defined as attachment of the spinal cord to the wall of the bony spinal canal, 8 is known to be a major factor in the occurrence of such a complication. [3][4][5]9,10 The long-term SCI patient follow-up highlights that PTM is a frequent complication among these patients. 2 In addition to urinary, respiratory, vascular or cutaneous complications, PTM should be screened for and treated.…”

“…PTMs, which can be either cystic (posttraumatic syringomyelia) or non-cystic (post-traumatic progressive myelomalacic myelopathy), are referred to as progressive pathologies. 3,5,6,11 The possibility that cord tethering could induce late lesions that would not be extensive but remain strictly limited to the injured area has not been evidenced in the literature. Our experience allowed us to identify patients who presented with such a pathology of the spinal cord.…”

Management of degenerative changes and stenosis of the lumbar spinal canal secondary to cervical spinal cord injury

“…It will be necessary to find out whether the increasing spasticity and autonomic dysreflexia have arisen through progressive post-traumatic myelomalacic myelopathy 11,12 or through bony changes in the lower lumbar spine with possible neural impingement.…”