Bilateral traumatic dislocation without fracture of the lumbosacral junction: case report and review of the literature.

STUDY

DESIGN

Case report.

OBJECTIVE

The diagnosis and surgical management of a patient with a traumatic bilateral dislocation of the lumbosacral junction (L5-S1) without facet or pars interarticularis fracture is presented with a thorough review of the existing literature.

SUMMARY OF BACKGROUND DATA: Lumbar fracture-dislocations have been widely reported. However, only five cases of lumbosacral junction dislocation without a fracture have been previously reported.

METHODS

A 23-year-old patient was involved in a high-energy occupational injury and presented with complaints of back pain and inability to ambulate. Neurological assessment confirmed adequate motor strength (4+/5 bilaterally), normal perianal and lower extremity sensation, and urinary retention (postvoid residual: 1000 mL). Imaging studies revealed bilateral L5-S1 facet dislocation (bilateral jumped facets) without articulating processes or pars interarticularis fractures. Three-column ligamentous injury was confirmed on magnetic resonance imaging with complete tear of the ligamentum flavum, anterior and posterior longitudinal ligaments, interspinous and supraspinous ligaments, and avulsion of the L5 spinous process. The patient underwent bilateral facetectomies, diskectomy, laminectomies, and reduction of slippage with interbody and posterolateral transpedicular instrumented fusion.

RESULTS

At 1-year follow-up, the patient reported mild back pain well controlled with naproxen. He continued to report good improvement in his daily function.

CONCLUSION

A careful clinical examination and imaging assessment must be done for appropriate diagnosis and treatment of this rare type of injury. Reduction in the face of intact articulating processes and pars interarticularis is challenging because of acting heavy forces on the lumbosacral joint. Facetectomies, nerve root decompression, and circumferential instrumented fusion are ways to decompress the neural elements, restore alignment, and maintain segmental stability.