Fracture-dislocation of the fifth lumbar vertebra - A new classification

We have studied fracture-dislocation of the fifth lumbar vertebra in seven patients and reviewed 50 previously reported cases. Based on this informati on, we have classified the injury into five types: type 1, unilateral lumbo sacral facet-dislocation with or without facet fracture; type 2, bilateral lumbosacral facet-dislocation with or without facet fracture; type 3, unila teral lumbosacral facet-dislocation and contralateral lumbosacral facet fra cture; type 4, dislocation of the body of L5 with bilateral fracture of the pars interarticularis; and type 5, dislocation of the body of L5 with frac ture of the body and/or pedicle, with or without injury of the lamina and/o r facet. Conservative treatment of fracture-dislocation of L5 is generally not effec tive because the lesion is fundamentally unstable. Planning of the operatio n should be made on the basis of the various types of injury.