Intraoperative conversion of artificial cervical disc replacement to anterior cervical discectomy and fusion for iatrogenic fracture

RATIONALE Artificial cervical disc replacement (ACDR) has been reported to be an effective and safe surgical treatment for cervical spondylosis. However, iatrogenic fracture during ACDR surgery has rarely been reported. Considering its infrequency, we report a rare clinical case, with the aim of sharing our experience and exploring when to convert ACDR to fusion intraoperatively. PATIENTS CONCERNS A 47-year-old woman felt neck pain with weakness and numbness in both upper limbs for 5 months. DIAGNOSES The patient had received discectomy and fusion procedure on C3/4 and C5/6 to relieve her radicular pain nearly 4 years prior. Neurologic examination revealed a diminished sensation at the C6-C8 skin areas and level Grade-4 power in the left wrist extensor and grip muscle strength. Magnetic resonance imaging (MRI) showed disc herniation compressing the spinal cord at C6/7. Computed tomography (CT) scans showed intervertebral fusion in both the C3/4 and C5/6 segments. INTERVENTIONS Surgery was performed to remove the plate and replace C6/7 with an artificial disc, but a transverse cleavage endplate cortical fracture was detected after cutting the blades. Thus, we terminated artificial cervical disc replacement intraoperatively and changed to discectomy and fusion in C6/7. OUTCOMES The patient's symptoms were remarkably relieved. Postoperative CT scans showed a transverse cleavage fracture in the backside of the C6 caudal endplate. Good fusion was achieved after 6 months. LESSONS Iatrogenic fracture during ACDR is rare but does occur in clinic practice. Complete examination and an alternative approach determined before surgery are important for operative safety. Anterior cervical discectomy and fusion (ACDF) is recommended as a feasible remedial surgical strategy if ACDR fails intraoperatively.