Cervical Spondylotic Myelopathy Anterior Corpectomy and Fusion with Plating - Case Management

CASE MANAGEMENT

Procedure

At surgery, this patient had a left side Smith–Robinson approach through a horizontal incision of 2 inches at C5–6 level. Following division of the platysma muscle and blunt dissection through deep cervical fascia and pretracheal fascia, the sternocleidomastoid muscle and carotid content were retracted laterally and the trachea, strap muscles, and esophagus were retracted medially. The prevertebral fascia was divided and the longus colli muscles were mobilized laterally. Intraoperative radiograph confirmed the correct level. Discectomies were performed first at C4–5, C5–6, and C6–7 levels, followed by C5 corpectomy. The spinal cord compression was more significant at C5–6 and C4–5 levels, and therefore, corpectomy was performed at this level, and discectomy at C6–7 level was done for adequate decompression of the spinal cord at this level. A tricortical strut graft from the left iliac crest was placed between C4 to C6 and a tricortical interbody graft was placed at C6–7. Anterior fixation was enhanced with Polyaxial Anterior Peak Plate fixation (Depuy–Acromed Inc., Raynham, MA). Vertebral screws were placed at C4, C6, and C7. The intermediate screws were angled inferiorly to purchase the C6 vertebral body (Fig. 4A ) The patient tolerated the two and a half hour operation well without any complications. The patient was hospitalized for 2 days. The wore a cervical soft collar for 4 weeks and a 5/5 muscle strength in all four extremities were noted at 4 weeks.

Postoperative Evaluation

At one–year follow–up, the patient presents signs of improvement with no significant upper extremity weakness, headache subsidence, negative Hoffman signs, and improved neck flexion and extension. Plain radiographs revealed postoperative changes with fusion from C4 to C7. Good positioning of the plate and screw fixation from C4 to C7 was noted (Fig. 4: A, B). Bone graft and strut graft were well positioned and healed. Overall alignment of the cervical spine had been well maintained. However, the patient's residual complaint of back pain and left lower extremity pain with difficulty walking was associated with severe stenosis above previous fusion. Therefore, removal of the lumbar spinal implant as well as a laminectomy and fusion extension of the upper lumbar region was performed and lumbar radiculopathic symptoms were resolved.

CONCLUSION

This case illustrates cervical spondylotic myelopathy associated with three level cervical stenosis and concomitant lumbar stenosis. Because of lumbar stenosis, upper motor neuron signs that are frequently present in patients with cervical myelopathy such hyperreflexia, Babinski signs, and clonus were absent in this patient. The patient's inability to walk is associated with both cervical myelopathy and lumbar stenosis. Careful clinical assessment and meticulous neuralgic examination will lead to making the correct diagnosis. When dealing with patients with both cervical and lumbar stenosis, the predominant symptoms and the degree of stenosis by imaging studies should be considered in deciding which area of the spine should be treated first. In general, significant myelopathic symptoms associated with cervical stenosis warrant early surgical intervention. Lumbar stenosis can be treated conservatively depending on the degree of pain and neurologic deficits. This patient in this report ultimately required both cervical and lumbar surgery.

Management of CSM by an anterior corpectomy and cervical fusion with rigid internal fixation is appropriate for up to three level stenosis. Cervical kyphosis resulting in myelopathy warrants anterior decompression rather than posterior decompression via a laminectomy. 1,26,36,40 Laminectomy to correct for cervical myelopathy with loss of lordosis has been shown to increase postoperative neural compromise, inadequately decompress the spinal cord, further attribute to kyphotic deformity, and increase the risk of subluxation. 14,21,22,23 The use of multiple discectomies and fusion may be considered if the spinal cord compression is only at the disc levels, not at the vertebral bodies. However, corpectomy is necessary in cases with spinal cord compression at the discs and vertebral bodies. On occasion, corpectomy at one level can be combined with discectomy at another level depending on the pathological analtomy as shown in this case report. Anterior cervical plating provides greater stability and facilitate fusion and decrease the risk of nonunion. 5,8,28 Screw fixation in the intermediate vertebra also enhances the stability of the construct. One should avoid a long construct with a strut graft with anterior plate fixation that only utilizes screws proximally and distally. Because of significant moment arm and postoperative subsidence, graft and plate failure is common in these constructs. In addition, if involved levels causing stenosis increases beyond three and preoperative cervical alignment is lordotic, then posterior surgical procedures such as laminoplasty or laminectomy with fusion should be considered.