PROGRESSIVE POSTTRAUMATIC MYELOMALACIC MYELOPATHY - TREATMENT WITH UNTETHERING AND EXPANSIVE DURAPLASTY

Patients with progressive posttraumatic myelomalacic myelopathy (PPMM) , or tethered cord syndrome, present with symptoms and signs similar t o those observed in cases of progressive posttraumatic cystic myelopat hy, that is, sensorimotor function deterioration, local and/or radicul ar pain, increased spasticity, increased autonomic dysreflexia, and sp hincter dysfunction. The authors investigated surgical outcomes of unt ethering combined with expansive duraplasty. Forty patients with PPMM who presented with functional deterioration underwent untethering of t he spinal cord and nerve roots with an expansive duraplasty. Meticulou s dissections of adhesions on the dorsal and lateral aspects of the sp inal cord and nerve roots were performed. Intraoperative ultrasonograp hy was used to detect the presence of a confluent cyst and to assess t he success of untethering. After surgery, the patients were treated us ing a protocol that involved frequent turning for 48 hours and subsequ ently mobilization. Preoperative magnetic resonance (MR) imaging, with and without administration of a contrast agent, was obtained in all p atients, except one patient who underwent immediate and delayed comput erized tomography (CT) myelography. The mean follow-up period was 3 ye ars (range 20-57 months) for the 36 patients available for follow-up r eview. Spinal cord tethering was observed in all patients preoperative ly. 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 even t 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 functi on deterioration was the most frequent manifestation; it was present i n 31 of 40 patients. improvements in motor function, autonomic dysrefl exia, pain, sphincter dysfunction, and sensory function were found dur ing the most recent follow-up examination in 79%, 75%, 62%, 50%, and 4 3% of the patients, respectively. Two patients experienced retethering of the spinal cord and one underwent a second operation. Surgical unt ethering and expansive duraplasty, followed by postoperative position rotation to avoid retethering, provide symptomatic relief for patients with PPMM.