Case Report: Two Level Artificial Disc Placement to Treat Spondylotic Cervical Myelopathy

History
This 56 year old woman presented with a 9 month history of severe L. arm pain and mechanical neck pain. The pain fitted into the C6 dermatome. Neurological examination showed 4/5 weakness of left biceps and left wrist extension.

Preoperative imaging, shown below, revealed spondylotic cervical disease with 2 level spinal cord compression, at C5-6 and C6-7.

Figure 1
Preoperative lateral cervical spine x-ray confirming spondylotic disease at the C5-6 and C6-7 levels.

Figure 2
Preoperative T2-weighted sagittal MR scan of the cervical spine. Compression of the cord is seen at 2 levels, C5-6 and C6-7 with high signal in the cord.

Figure 3
Preoperative CT scan at the C5-6 level confirming spondylotic osteophytic cord compression, with likely L. C6 root compression.

Figure 4
At the C6-7 level, a broad osteophytic bar causing a reduction in A-P canal diameter is noted.

The patient was initially managed with conservative therapy in view of the lack of clinical myelopathy but continued to be troubled by neck and left arm pain. As a result surgical intervention was offered. The C5-6 level wad thought to be causing the arm pain but in view of the adjacent level disease a single level spinal fusion was thought to be an undesirable option as it was felt she would either be left with a relatively more rigid neck, or if only one level was fused, run the risk of having further surgery in the future. As such, a 2 level artificial disk replacement was offered, after discectomy and decompression.

Operative Details
Via a left-sided approach an extensile exposure of the C5-6 and C6-7 disk spaces was effected. Using the Bryan disk apparatus, a discectomy at 5-6 was performed and after decompression of the cord and nerve roots at this level, a 16 mm disk prosthesis was placed. This was then repeated at the C6-7 level. There were no operative complications and a blood transfusion was not required. At the end of the case, the patient was observed in the HDU without a cervical collar.