Lumbar Posterolateral Fusion Mass Fracture Induced by a Minor Fall: A Case Report

Posterolateral fusion is an integral type of treatment for spinal instability with certain well known complications. However, fusion mass fracture as a cause of late-onset back pain has not been reported. A 72-year-old male patient with lumbar spinal stenosis and degenerative spondylolisthesis received posterior decompression and posterolateral fusion over 10 years ago. He had been doing well until he slipped and fell for one time. Since then, back pain and sciatica with postural change became progressive and intolerable. From the CT scan images, we suspected a fusion mass fracture has formed. The result of Tc-99m bone scan was well correlated to the level indicated in CT scan images. Fractures of the posterolateral fusion mass of the lumbar spine were found intraoperatively at the disc level. Wide decompression and posterolateral fusion with internal fixation from L2 to L5 were performed after removal of broken implant. The patient had smooth postoperative clinical recovery. Fusion mass fracture might be considered as one of the differential diagnoses for patients with back pain after spinal fusion.