Cervical-thoracic Spine Inclination (CTSI): Anatomy Peculiarities and Surgical Options

Abstract

Introduction

The bayonet congenital abnormality of cervical-thoracic spine was previously described as a rarest clinical case under the title “congenital upper spine spondylolisthesis ” (Tokgozoglu AM et all., 1994) or “congenital dislocation of the cervical spine” (Shintaki M et all., 2013) without detailed description of anatomy and principles of surgical treatment. Our series include analysis of 10 CTSI cases from 4 clinics.

Material and Methods

Clinical, X-ray, CT and MRI peculiarities of 10 patients aged from 1 year 8 mns till 15 years were analyzed. The repeated cervical-thoracic abnormality included antero-posterior and cranial-caudad shift of the spine into the cervical spinal canal. All patients had arcs dysplasia, but any case has a complete posterior segmental defects, MMC or split spinal cord syndrome.

Results

According to Frankel scale the neurological status was estimated as a type E in one patient, type D – in 4, type C - in 4 and type B in one, incl. two paraparesis and 7 tetraparesis cases. Cranial spine was formed by 4 till 8 vertebrae (max – 6 vertebrae in 5 cases). Abnormality was accompanied by Sprengel disease in 2, by neurofibromatosis type I in one, by failure of segmentation (Klippel-Feil syndrome) in 5 and neural arc dysplasia in 10 cases. 9/10 patients were operated. The operations included circular decompression of spinal cord and posterior instrumentation; 8 operations were done from posterior approach only, 1 - from anterior and posterior approaches. Four procedures were done with Halo-cast fixation to produce pre-surgical local spinal stability. The post-op follow up floated from 7 month till 5 years. 6/9 patients demonstrated significant improvement in neurological sighs (one or more steps in Frankel scale) ; the neurological deterioration was occur in 2/9 cases, followed by a partial recovery in one and complete in another.

Conclusion

Our 10 cases series demonstrates a extremely rare type of the cervical-thoracic spinal abnormality. We the term “the cervical-thoracic spine inclination (CTSI)” because it reminiscent the cranial-vertebral pathology known as “the inclination of dens of C2 into foramen magnum.” From our point of view the inclination is a combined type of pathology which included an anterior-posterior and cranial displacement of caudal spinal segment(s); this pathology typical for transitional spinal zones and looks like spinal segmental dysgenesis but differ due to the absence of circular spinal column defect despite the combination of different types of vertebral abnormalities. CTSI is a repeated spinal syndrome which has a high risk of neurological complications. The spinal cord decompression and instrumentation are mandatory for this abnormality; the surgery could be done from the posterior approach only.