Cervical Disc Replacement with a Keeled Implant Causing an Intraoperative Fracture: a Case Report

Introduction Cervical disc replacement (CDR) has quickly gained popularity for treating cervical disc degenerative pathologies, as it can preserve natural function and reduce adjacent segment disease. Numerous implants have been developed to optimize patient outcomes; and while progress has been made, each implant comes with its own nuance for safe placement. Our case describes the post operative discovery of an intraoperative fracture during a multilevel hybrid ACDF-CDR procedure with a keeled implant. Clinical Presentation A 53-year-old former smoking female presented with a one-year history of bilateral 8/10 radiating neck pain that began after a fall. Radiographic films demonstrated C4-5 cervical spondylolisthesis and degenerative disc disease with foraminal stenosis at C5-C7. The patient was preoperatively diagnosed with cervical radiculopathy at C4-7 and the consented to CDR from C5-C7 and ACDF at C4-C5. Immediately postoperatively the patient had incomplete loss of motor and sensation below the biceps bilaterally and CT imaging revealed a fracture of the proximal posterior corner of C6 leading to retro-vertebral stenosis of the spinal canal. The patient returned to the OR for revision surgery and was successfully treated with a C6 corpectomy. Immediate post operative symptoms improved mild paresthesias. The patient observed a full recovery of strength and sensation by five months. Conclusion Maintaining endplate integrity is crucial to performing a CDR with a keeled implant and it is important to be gentle when chiseling the end plates. Be patient when progressing the implant and refrain from increasing the pressure to force the implant into position.