Lessons Learned After 9 Years' Clinical Experience with 3 Different Nucleus Replacement Devices

Nucleus replacement devices have been developed with the goal of treating moderate forms of degenerative disk disease, trying to fill the gap between discectomy and fusion. This is a retrospective analysis of a nonrandomized, single-center clinical series of 125 patients, presenting with moderate forms of degenerative disk disease and treated with nuclear replacement devices. Eighty patients were treated with prosthetic disk nucleus (Ray Medica) disk prosthesis, 26 patients with percutaneous nucleus replacement (TranS1), and 19 patients using the NUBAC (Pioneer) devices. The surgical techniques for each device were performed following the prosthesis indications. Patients were followed up to 9 years postoperatively, and their complications were recorded. After 9 years' follow-up, the overall retrieval incidence was 48.8% (61/125). Of these, 15 (57.7%) had PNR failures, 8 (42.1%) experienced NUBAC retrievals, and 38 (47.5%) had prosthetic disk nucleus flaws. The failures included significant loss of disk height at the operated level, displacement, silicon inside the spinal canal, and migration. All patients underwent fusion as a retrieval surgery. The retrieval rate in our series was very high. It shows that endplate reactions occur in a high percentage of patients over time, resulting in subsidence and mechanical back pain. Device expulsion was another cause of pain requiring revision surgery.