Implant Failure of Bryan Cervical Disc due to Broken Polyurethane Sheath A Case Report

Study Design. A case report. Objective. A rare case of Bryan disc implantation failure due to broken polyurethane sheath was reported. The bone ingrowth at implant-bone interface and wear debris leaking from broken Bryan disc were also observed. Summary of Background Data. The Bryan disc is one of the most commonly used cervical prostheses and has shown satisfactory results compared with anterior cervical discectomy and fusion in short-and long-term follow-up. The complications, including neurological worsening, heterotopic ossification, kyphosis, and so forth, still occur, although infrequently. The broken polyurethane sheath is an extremely rare complication that has seldom been reported before. Methods. A 55-year-old female patient experienecd progressive neck pain after 8 years of Bryan disc implantation because of cervical spondylotic myelopathy at C5-C6 level. The subsequent magnetic resonance imaging scan demonstrated a cystic mass in front of Bryan disc, with high-signal intensity on T2-weighted images. The Bryan disc was removed and segment (C5-C6) was fused with cage and plate. The bone ingrowth and wear debris of retrieved Bryan disc were studied. Results. In revision surgery, a cyst with thick pseudocapsule connecting the anterior part of Bryan disc was excised. A transverse crack (5 mm) was identified in the anterior part of polyurethane sheath. The bacteria test of fluid from the cyst showed a negative result. Micro-computed tomography and histological study both indicated abundant bone ingrowth at implant-bone interface. The metal wear debris could be observed around titanium alloy shells. Conclusion. This case demonstrates the unique incident of broken Bryan disc after 8 years of implantation. Follow-up imaging shortly after the procedure should be mandatory to monitor such potential complication.