Transient paraparesis: a complication of the surgical management of Scheuermann's kyphosis secondary to thoracic stenosis

Abstract

Study design: Transient paraparesis during the operative management of a 16-year-old patient with Scheuermann's kyphosis secondary to thoracic stenosis is reported.

Objective: To describe a treatable cause for paraparesis in a patient with Scheuermann's kyphosis undergoing surgical treatment.

Summary of background data: Cord injury in the surgical treatment of Scheuermann's kyphosis is a rare event, yet it is felt to be more common in the surgical correction of kyphosis than in surgery for scoliosis. Suggested etiologies have included vascular insufficiency, hypotension, direct mechanical trauma, and neural element stretch. Concomitant thoracic spinal stenosis predisposing to neurologic injury during surgical manipulation has not been reported.

Methods: A 16-year-old boy with progressive Scheuermann's kyphosis measuring 80 degrees from T7 to T12 underwent an anteroposterior spinal fusion with somatosensory-evoked potential monitoring and wake-up tests. During the instrumentation posteriorly, somatosensory-evoked potential monitoring became markedly abnormal. This was followed by a wake-up test that demonstrated the patient's inability to move either of his lower extremities. All instrumentation was removed. The patient had recovered neurologic function by the time he reached the recovery room. A computed tomography myelogram was performed on the third postoperative day, which demonstrated severe thoracic stenosis from T8 to T10. The patient was returned to the operating room 1 week later to undergo a posterior laminectomy from T7 to T11 and instrumented fusion from T5 to L2. Somatosensory-evoked potential monitoring was stable throughout this procedure, and the wake-up test was normal.

Results: The patient's postoperative course and subsequent 2-year follow-up period were unremarkable. He progressed to clinical and radiographic union and maintained a normal lower extremity neurologic examination.

Conclusions: A treatable cause for paraparesis secondary to the surgical treatment of Scheuermann's kyphosis is presented. The author currently obtains a thoracic magnetic resonance image (MRI) before the surgical correction of any patients with Scheuermann's kyphosis.