An unexpected cause of intractable dysphagia after 20 years following cervical spine instrumentation using bone cement alone: a case report.

Introduction and importance: Postoperative dysphagia following anterior cervical discectomy fusion (ACDF) for cervical disc herniation is still poorly understood. Dysphagia after anterior spinal cervical approach is mild and transient. Here, the authors present a rare case suffering with severe progressive dysphagia for over 1 year after 20 years of ACDF due to expulsed bone cement abutting the esophagus which was successfully removed after reoperation.

Case presentation: A 59-year-old homemaker female presented to us with a foreign body sensation in the throat 'globus pharyngeus' and progressive difficulty in swallowing for 1 year. She was previously operated for C5-C6 cervical intervertebral disc prolapse via ACDF using bone cement at another center. On examination, power in the left upper limb was MRC grade 3, and the left-hand grip was 25% only. MRI of the cervical spine showed increased prevertebral soft tissue space and a notable rectangular-shaped black prevertebral shadow at the C5-C6 level, causing esophageal compression. The patient underwent an exploration of previous ACDF surgery. Intraoperative findings revealed an extruded piece of bone cement of size ~2×1.5×1 cm³ at C₅-C₆ disc space level, compressing the esophagus. The yellowish extruded piece was removed and C₅-C₆ was reinforced with an anterior cervical plate with screws. The postoperative course was uneventful.

Clinical discussion: The exact pathophysiology of dysphagia after ACF surgery remains unknown. In our case, there was an expulsion of the graft. The graft used was polymethyl methacrylate, commonly known as bone cement, which was placed 20 years back. Since polymethyl methacrylate is bioinert material, the graft may have expulsed from its site of placement and thus compressed the esophagus. Taking into consideration of the cost-effectiveness and maintenance of spinal mobility, few neurosurgeons believe that the application of bone cement in ACF surgery as a spacer is a safe and very cost-effective modality compared to modern expensive artificial disc.

Conclusion: Dysphagia after ACDF surgery is usually underrecognized. Although the serious complications after ACDF surgery are rare, dysphagia can cause prolonged morbidity to patients. Using bone cement alone for ACDF surgery may carry the risk of its anterior expulsion even after a long period of surgery.