Artificial disc replacement (ADR) for the lumbar spine is still a new treatment of disc problems. Reports of problems and complications after implantation are few and far between. In this case study, doctors tell about one patient who had an ADR that had to be removed.
The disc implant moved forward and cut off a major blood vessel to the leg. Three weeks after the operation the patient reported increased back pain. By four weeks he had leg weakness and decreased sensation on the right side.
The ADR had to be removed and a spinal fusion done instead. The authors of this study give a careful and detailed report of the technical aspects in removing this ADR. The surgeon found that the top half of the implant had moved forward. Damage to the vertebra occurred as the anchoring teeth of the implant scraped across the bone.
This is the first report of endplate migration after ADR. Only one other case of ADR failure and removal has been published. In this case the surgeon who removed the device said that the implant was probably placed too far forward. The center of rotation of the ADR was forward of the patient’s natural center of rotation. The uneven force pushed the implant out of the disc space.
In the future ADR may replace spinal fusion for many patients. For now problems reported will help improve the implant design. Wear debris and movement of the implant are two major concerns with ADRs.