Posterior lumbar interbody fusion graft penetrated the lumbar thecal sac in a patient with rheumatoid arthritis: A case report

INTRODUCTION: Intradural foreign bodies have been reported to be associated with disc material, tumors, and bullets following spinal gunshot injuries. In this report, we describe a case of non-union with minor trauma that caused interbody bone graft material to migrate into the intrathecal area in a patient with RA. PRESENTATION OF CASE: We present the case of a 65-year-old woman visited an outpatient clinic of our hospital after experiencing progressive lower extremity weakness, and voiding and defecation difficulty after fell down several times in the past. She had a history of two spinal decompression with fixation surgeries due to spinal stenosis with a herniated intervertebral disc. She was prescribed steroids and methotrexate for the RA. The results of MRI and CT demonstrated an intradural bone graft material migration with cauda equina syndrome after revision lumbar stenosis surgery. Calcified material protruded to the intracanal area and compressed the cauda equina fiber. After the removal of fragments operation, she recovered from cauda equina symptoms. A follow-up examination two years postoperatively revealed clinical resolution of cauda equina symptoms and a return to partial walking with a cane. DISCUSSION: The patient had a minor or major trauma, such as a fall, after the revision surgery. After that trauma, the patient presented with some dural injury, kyphotic position, or non-union state causing the dural penetration of the interbody fusion material. CONCLUSION: The first report describing displaced PLIF graft material that penetrated the dural sac and caused cauda equina symptoms in a patient with RA. Establishing strategies to minimize these complications is indicated when treating degenerative lumbar spine conditions in patients with RA.