Dorsal Cervical Spinal Cord Herniation Precipitated by Kyphosis Deformity Correction for Spinal Cord Tethering.

INTRODUCTION: Cervical spinal cord herniation is a rare clinical entity. Reported after previous intradural surgery or surgery complicated by durotomy, patients return several months to years later with symptoms of worsening myelopathy. Herein is presented a case of a 51-year-old female patient with spinal cord herniation in the cervical spine after kyphosis deformity correction.

CASE DESCRIPTION: A 51-year old female patient presented to the neurosurgery clinic with worsening cervical myelopathy due to cervical spinal cord tethering and adhesions from previous intradural surgery for Chiari malformation. Conservative treatment initially was recommended but ultimately unsuccessful, as her neurologic function continued to deteriorate. Follow-up imaging demonstrated progressive cervical kyphotic deformity with stability of the tethered spinal cord. The patient underwent cervical deformity correction to reduce tension on the spinal cord, after which her neurologic symptoms stabilized and began to improve with physical therapy. Four months after surgery, she returned to clinic with recurrence of cervical myelopathy. Repeat imaging demonstrated herniation of the cervical spinal cord through a dorsal defect, and the patient was treated successfully with a wide cervical duraplasty to recreate an intact thecal sac.

CONCLUSIONS: The inability of the spinal cord to compensate for changes in spinal alignment in cases of tethering makes it susceptible to increased pressure and tension at the point of tethering. Caution is urged when attempting deformity correction in the presence of spinal cord tethering, which may limit the capacity of the spinal cord and surrounding tissue to compensate for alterations in spinal alignment.