Neurological L5 burst fracture: posterior decompression and lordotic fixation as treatment of choice

Abstract

Purpose: We report our experience and literature review concerning surgical treatment of neurological burst fractures of the fifth lumbar vertebra.

Materials and methods: Nineteen patients with L5 neurological burst fractures were consecutively enrolled; 6 patients had complete motor deficits, and 12 had sphincter dysfunction. We performed 18 posterior and one combined approaches. To avoid kyphosis, posterior internal fixation was achieved by positioning patients on the operating table with hips and knees fully extended. At the latest follow-up (mean 22 months, range 10-66), neurological recovery, canal remodeling and L4-S1 angle were evaluated.

Results: Vertebral body replacement was difficult, which therefore resulted in an oblique position of the cage. Vertebral bodies still remained deformed, even though fixation allowed for an acceptable profile (22°, range 20-35). We observed three cases of paralysis, five complete, and three incomplete recoveries. In the remaining eight patients, sphincter impairment was the only finding. In 15 patients, pain was absent or occasional; in four individuals, it was continuous but not invalidating. Remodeling was visible by X-ray and/or CT, without significant secondary stenosis.

Conclusions: The L5 burst fractures are rare and mostly due to axial compression. Cauda and/or nerve root injuries are absolute indications for surgery. If an anterior approach is technically difficult, laminectomy can allow for decompression, and it can be easily combined with transpedicular screw fixation. Posterior instrumented fusion, also performed with the aim to restore sagittal profile, when associated with an accurate spinal canal exploration and decompression, may be looked at as an optimal treatment for neurological L5 burst fractures.

Fig. 1

L5 fracture in a 61-year-old woman. a, b axial and sagittal CT reconstruction that shows an A3.3 burst fracture, c MRI shows neural compression, d post-operative CT at 1 year follow-up shows bone healing and residual deformity of the vertebral body, e axial-loading CT that shows a good sagittal profile (L4–S1 angle >30°)

Fig. 2

a CT scan (sagittal reconstruction) shows the dislocated bony fragment with compression of the cauda equina, b CT three-dimensional reconstruction shows L4–S1 fixation, fracture reduction, and posterior fusion, c CT scan (sagittal reconstruction) demonstrates fracture healing and spinal canal remodeling at 1 year follow-up. Patient had residual sphincter dysfunction with score 2 (moderate)