Floating lumbar spine: proposed mechanism with review of literature.

Hyperextension injuries of lumbar spine resulting in lumbosacral dislocation are a rare entity. We report a case of a 60-year-old male who presented to us in outpatient department with history of trivial fall from bicycle with fracture through the pedicles extending from L2 to L5 with lumbosacral dislocation with free floating posterior elements with intact neurology. This is the first case report of 4 level extension compression injury with lumbosacral dislocation leading to floating lumbar spine to the best of author's knowledge. Treatment consists of reduction of the lumbosacral dislocation first and fusion of the disc space followed by reduction of the other fractures proximally. These injuries may present with a trivial trauma in spondylotic spine in elderly patients. MRI and CT scan should be done early to identify it, reduce and fix it, as in many cases with trivial trauma there may be no neural deficit.