Circumferential Approaches for the Correction of Occipitocervical and Subaxial Deformity

Introduction:

The literature on spinal deformity surgery is heavily weighted toward thoracic and thoracolumbar reconstruction. At our institution, more than 50 cases of multi segmental cervical or occipitocervical deformity corrections have been performed since 1995. Thirty such cases have at least 2 years of followup.

Methods:

All subaxial deformity cases involve sagittal plane correction for kyphosis. One quarter of such cases simultaneously involve coronal and/or axial plane correction as well. 18 supra–axial cases involve sagittal plane correction in 12, axial or coronal plane correction in 8. Causative pathology is congenital, post–surgical, tumor or infection. Two–thirds of all cases involved a 360 degree or 540 degree circumferential approach. Anterior (including transoral) reconstruction usually involved titanium cage and buttress plate or rod instrumentation; posterior fixation usually involved non–constrained plates or rods and cables. All used cancellous autograft except for malignant tumor cases.

Results:

An aggressive approach to anterior and posterior osteotomy followed by anterior distraction and posterior compression allowed correction of kyphotic deformity intraoperatively in all cases. Late loss of lordosis occurred in 1/3 of cases secondary to cage settling or telescoping. Rigid fixation from the skull to the axis or subaxial spine allowed near complete correction of the cervicomedullary junction in all cases with no late loss of correction. No patient suffered a cord injury. There was one superficial wound infection. There were two vertebral artery injuries one of which was associated with a delayed stroke. There were two next segment failures requiring late reoperation for extension of fusion.

Discussion:

Modern reconstructive techniques allow for clinically significant correction of cervical and occipitocervical deformities associated with chronic pain, neurologic deficit, and cosmetic deformity. An aggressive circumferential approach to decompression and osteotomy allows near anatomic correction of geometric deformity in any plane. Evolving hardware improvements allow anterior and posterior fixation. Clinically significant obstacles remain in the development of non–telescoping devices for anterior column reconstruction and in constrained posterior fixation.