Progressive vertebral body osteolysis after cervical disc arthroplasty

Study Design. Case report. Objective. To review the management of a patient with progressive osteolysis of the vertebral body after undergoing cervical arthroplasty for management of a refractory radiculopathy. Summary of Background Data. Since the Food and Drug Administration's (FDA) approval of cervical arthroplasty devices in 2007, many surgeons have incorporated this technology into clinical practice. As arthroplasty becomes more widespread, complications unique to this technology are inevitable. To date, only a limited number of complications have been reported in the literature suggesting the safety of this device. To the authors' knowledge, this report represents the first complication of osteolysis from a keel based arthroplasty device. Methods. A 30-year-old man underwent an uneventful C5-C6 total disc arthroplasty with initial benefit. Progressively worsening neck pain prompted repeat imaging at 9 and 15 months, which showed a progressive osteolytic process in the vicinity of the keel of the superior alloy endplate. This necessitated exploration of the surgical site, explantation of the implant and conversion of the disc arthroplasty to an arthrodesis. Results. Examination of the osteolytic area did not reveal any gross abnormalities. Testing of the device by the manufacturer did not reveal any defects. A comprehensive infectious workup was negative. The osteolytic process halted after the explantation of the device. A bony arthrodesis was achieved at 6 months and the patient remains symptom free 29 months after the initial procedure and 14 months after the revision. Conclusion. This report illustrates an exceptional case of a progressive osteolysis with a keel based arthroplasty device. An immune mediated osteolytic process appears to be a plausible explanation for the clinical symptoms and radiographic progression seen in this case. Given the years of use of the ProDisc-C since its FDA approval in 2007, complications with this device are rare. This represents the first reported case of osteolysis from such an implant.