[Clinical feature and preliminary surgical outcome of traumatic lumbar spondylolisthesis]

To analyze the clinical features and preliminary outcome of posterior operation for traumatic lumbar spondylolisthesis.

The clinical data of 11 patients with traumatic lumbar spondylolisthesis who underwent surgeries between January 2008 and June 2012 were retrospectively analyzed. There were 6 male and 5 female patients, aged from 13 to 60 years with a median age of 38 years. The mechanism of injury included heavy pressure injury in 4 cases, falling injury from height in 4 cases, and traffic accident injury in 3 cases. The time of injury to operation was between 3 days and 13 years (median, 20 days). According to Frankel neurological function grading, 2 patients were rated as grade E, 4 as grade D, 3 as grade C, and 2 as grade B before operation; according to Meyerding spondylolisthesis grading, 4 cases were classified as degree I, 4 as degree II, 2 as degree III, and 1 as degree IV preoperatively. The affected segments included L4 in 3 and L5 in 8 patients. The surgical fixation segments were L4, 5 in 2 patients, L5, S1 in 7, and L4-S1 in 2. Eight patients underwent circumferential fusion, while 3 patients underwent posterolateral fusion. The reduction of spondylolisthesis and bone graft fusion were assessed on X-ray films and three-dimensional CT scans during follow-up. The clinical outcomes were evaluated by visual analogue scale (VAS) and Oswestry disability index (ODI) scores.

All patients achieved primary healing of incision after operation. And all patients were followed up 6-40 months with a median time of 12 months. There was no pulling-out or breaking of internal fixation. The fusion rate was 100% on three-dimensional CT scans, and the fusion time was 3-6 months (mean, 4.5 months). The spondylolisthesis was degree 0 in 10 cases and degree I in 1 case according to Meyerding grading, showing significant difference when compared with preoperative spondylolisthesis grading (Z = -2.979, P = 0.003). The Frankel neurological function grading were E in 6, D in 3, and C in 2 at last follow-up, which were significantly improved when compared with preoperative one (Z = -2.271, P = 0.014). At 1 week after operation and last follow-up, VAS and ODI scores were significantly improved when compared with the preoperative scores (P < 0.05); however, no significant difference was found between at 1 week and at last follow-up (P > 0.05).

If lumbar X-ray films suggest multiple fractures of transverses in emergency combined with the mechanism of injury, it strongly indicates the diagnosis of traumatic lumbar spondylolisthesis, moreover earlier decompression and fusion can provide the recovering of the neurological function and satisfactory preliminary effectiveness in these patients.