Purpose: The incidence of postraumatic vertebromedullary syringomyelia is difficult to estimate but the most recent series have reported 28%. The purpose of this retrospective study was to search for risk factors of symptomatic posttraumatic syringomyelia (PTS) and to propose an adapted approach for early management.

Material and methods: Forty-six patients consulted for symptomatic PTS 14 years (range 9 months – 45 years) after their trauma. Half of the patients had initially undergone treatment (osteosynthesis in 74% and laminectomy in 70%). Physical signs, the Frankel score, measure of functional independence (MFI) at discovery of PTS were compared with findings early after trauma. Local kyphosis and residual canal stenosis were measured. The location, length, and extension of the syringomyelic cavity, presence of arachnoiditis, and freedom of the subarachnoid spaces were studied on magnetic resonance images. Intra-cystic and perimedullary fluid flow was also quantified.

Results: Gender, age, vertebral level, and degree of initial neurological deficit were not predictive of symptomatic PTS. Clinical signs of PTS were pain, paraesthesia, or supra-lesion motor deficit in two-thirds of the patients, bladder sphincter disorders or aggravation of sub-lesion residual motricity in the others. The MFIwas statistically decreased compared with the initial evaluation. Clinical signs were significantly correlated with intracavitary velometric measures. There was no correlation between clinical severity, time to development of PTS, initial treatment (surgery versus orthopaedic), and the kyphosis value or degree of stenosis. When residual kyphosis was greater than 35° or when canal narrowing was greater than 30%, the cavity was more extensive.

Discussion: It is important to search for PTS in subjects with a history of vertebromedullary injury who present changes in the clinical or functional presentation (aggravation of MFI) late after trauma. MRI velometry provides a better understanding of progression of postraumatic cystic myelopathy. The degree of kyphosis and canal stenosis appear to be predictive of lesion extension.

Conclusion: Initial correction of spinal deformations after trauma and recalibration of the spinal canal help prevent development and aggravation of PTS.

Purpose: The purpose of this retrospective study was to report outcome after surgical treatment of posttraumatic syringomyelia (PTS) and examine the different techniques.

Material and methods: Between 1984 and 2001, 31 patients underwent surgery for cyst derivation (group D, n= 21) or arachnoid release (group R, n = 10). Outcome was assessed on the basis of postoperative changes in clinical presentation (pain) and function (measure of functional independence, MFI). Morphology results were assessed using the Vaquero index (VI) measured on the magnetic resonance images (MRI).

Results: After surgery, aggravation of posterior cord sensitivity was observed in 24% of the patients in group D and in 10% in group R. At last follow-up, there was a statistically significant improvement in pain in the supra- and infra-lesion levels. The Frankel score was stable in 77% and the MFImotor score was stable in 76%. Morphologically, there was a significant diminution in the VI in both groups. MRI velometric studies were performed in seven patients. Cystic systolic and diastolic flow rates were higher preoperatively in patients with more severe clinical grade. Postoperatively (mean 14 months), intra-cystic systolic flow rates decreased significantly (p=0.017). Perimedullary systolic flow rates, which were initially very low reached high levels postoperatively due to re-circulation in the perimedullary subarachnoid space. Re-operation rate was 43% at 39 months for patients in group D (man follow-up 36 months), and 20% in group R (mean follow-up 31 months). The complication rate was 11% (two scar infections, one meningitis, one pneumonia, one acute derivation dysfunction).

Discussion: Arachnoid release yielded a lower re-operation rate than derivations with a lower rate of postoperative posterior cord involvement and an identical functional and morphological outcome. We propose a schema for determining the indication for intra- and extra-dural interventions in the treatment of PTS.