Study design: Case report.
Objective: To describe the surgical technique and outcome of 2 cases of lap-shoulder belt injury involving burst fracture at L5 and cauda equina syndrome (CES).
Summary of background data: Lap-shoulder belts have largely replaced lap belts in the front seats of cars, and therefore the concept of seat belt injury needs re-evaluation.
Methods: Two adults, the driver and front seat passenger in the same car involved in a collision, sustained lap-shoulder belt injury. One developed L5 Denis type A burst fracture and the other developed L5 Denis type B burst fracture. Both had CES. They were surgically managed by decompression of the spinal canal, which included removal of retropulsed fragments without impacting them. Both patients received short-segment transpedicle screws and rod system instrumentation without the fractured vertebra being included.
Results: The percentage of preoperative degree of canal displacement of the retropulsed fragment was 60% in one patient and 55% in the other based on computed tomography. The mechanism of injury in both patients might be axial loading. After surgical intervention, the CES including lower leg weakness/numbness and bladder/bowel dysfunction clinically improved in both patients.
Conclusion: Two adults in the same car involved in a collision were wearing lap-shoulder belts, and 1 had Denis type A burst fracture at L5 and the other had Denis type B burst fracture at L5. Both developed CES after the accident. Both patients had a good clinical outcome after surgical treatment.