Summary: The cervical spines of patients with complex thoracolumbar deformities were routinely imaged as part of the preoperative workup at one practice. The incidence of anatomic and critical cervical stenosis, moderate to severe clinical signs of myelopathy, and cord edema was evaluated in this retrospective study. Surgical treatment of cervical stenosis in patients prior to adult spinal deformity correction, complications and future recommendations are also discussed.
Introduction: Adult spinal deformity patients with cervical stenosis have multiple risk factors for initiation or worsening of cervical myelopathy during and after spinal deformity surgery. These include prone positioning in slight extension, fluid shifts, variable intraoperative blood pressure, and prolonged anesthesia effects on spinal cord monitoring. One surgeon's practice was evaluated after a protocol for routine imaging of the cervical spine was initiated.
Methods: 80 spinal deformity patients over 50 yo were identified with 2 year follow up who had their cervical spine routinely imaged as part of their preoperative work up for thoracolumbar (TL) reconstructions (2005 to 2008). Clinic and hospital charts as well as radiographs were reviewed.
Results: Incidence of overt moderate to severe clinical cervical myelopathy was 5 of 80. Incidence of critical stenosis (AP canal diameter ≤7mm) with mild myelopathy was 6 of 80. Incidence of cord edema was 1 of 80. 11 of these 12 had cervical spine surgeries performed prior to having surgical correction of the TL deformity. The one patient with critical stenosis (canal ≤ 7mm) and mild myelopathy refused cervical surgery. Given her lower extremity deficits, she had deformity corrective surgery first. Intraoperative tcMEP and SSEP were stable. Postoperatively, the patient developed progressive cervical myelopathy. Surgery wasthen performed. The patient had stabilization but only mild improvement of her cervical myelopathy. Incidence of anatomic stenosis (AP canal diameter 8 ‐ 10 mm) without overt clinical myelopathy was 30 out of 80 (37.5%). This group did not have cervical surgery prior to deformity corrective surgery and had no long term sequelae postoperatively.
Conclusion: Cervical myelopathy and occult severe cervical stenosis are often difficult to ascertain on H & P in older adult patients. Often, severe long tract signs are not present and gait dysfunction is attributed to the TL deformity. We recommend routine imaging of the cervical spine in addition to detailed exams of hand function as part of any preoperative work up for adult spinal deformity surgery.