Lumbar Arthroplasty Core Herniation Presenting With Cauda Equina Syndrome: Case Report of a Rare Complication.

BACKGROUND

Treatment failures of artificial disc implantation are well-described, but posterior herniation of the arthroplasty core is rare. We present a case of posterior herniation of the arthroplasty core resulting in cauda equina syndrome in a 36-yr-old woman. Preoperative imaging studies including computed tomography (CT), magnetic resonance imaging (MRI), and CT Myelogram were performed; only the CT Myelogram demonstrated the severe compression well. This report highlights the radiographic findings on multiple imaging modalities, clinical implications, and management considerations of posterior arthroplasty failures.

OBJECTIVE

To demonstrate a rare complication of lumbar arthroplasties. The biomechanical considerations, surgical management, and thorough radiographic work-up demonstrate successful diagnosis and treatment of this unusual complication.

METHODS

The patient's chart was reviewed for medical history, laboratory and radiographic studies, and outpatient clinical follow-up.

RESULTS

After imaging work-up, this patient was found to have a herniation of the arthroplasty core at L5-S1. She was taken emergently to the operating room for a decompression at L5-S1 and arthroplasty core removal. She made some recovery neurological, but over 3 mo time, she developed a spondylolisthesis with new back pain and radiculopathy. This ultimately responded well to an L5-S1 instrumented posterior fusion.

CONCLUSION

Posterior herniation of the lumbar arthroplasty core is a rare complication from implantation of an artificial lumbar disc. Confirmation of the diagnosis is best confirmed with a CT Myelogram. Furthermore, this case underscores the biomechanical importance of the artificial disc given the development of the spondylolisthesis after removal, and fusion after arthroplasty core removal should be considered.