Spondyloptosis is a form of the spine dislocation or advenced spondylolisthesis, in which spondyloptotic corpus is fully dislocated in anterior or posterior space of the other one2). Spondyloptosis can be seen after trauma, or in the course of neoplastic or congenital diseases2). Lumbar spine is the most common affected area for spondyloptosis4). Subaxial cervical spine can be affected rarely. Only a few cases have been reported in the literature2-4). In this report we present a case of traumatic C6-7 spondyloptosis and discuss the current surgical treatment modalities, in the light of the relevant literature.

A 51-year-old female patient was transported to our hospital's emergency department after a vehicle accident. The patient had diabetes mellitus for 10 years and she developed a hypoglicemic coma in the day of accident. The patient was quadriparetic (MRC power 4/5, Asia D) with severe neck pain. Plain radiographs, computerize tomography and spinal magnetic resonance imaging showed C6-7 spondyloptosis and C5, C6 posterior element fractures (Fig. 1). Gardner-Wells skeleton traction was applied with 7 kg, after radiological evaluation. The traction weight was increased gradually and achieved to total 20 kg. Spinal alignment was reachived by traction and dislocation was decreased to a grade 1 spondylolisthesis. Then the patient was initially operated by anterior approach. Anterior decompression was achieved by C6-7 discectomy. The anterior longitudinal ligament was torn and a cerebrospinal fluid (CSF) leakage was detected from a dural defect. Dural defect repaired partially by a synthetic dural substitute and fibrin sealant. Anterior stabilization was performed by C5-7 screw-plate system. The fusion was achieved by a cadaver fibula graft. A lumbar drainage system was placed after operation and CSF was drainaged continuously for 5 days. Seven days after first operation the patient was operated by a posterior approach. C5 partial, C6 total laminectomy and foraminotomy was performed. The posterior stabilization was performed C4 to T2 by C4-5 lateral mass and T1-T2 transpedicular screw fixation and constructs. Also, posterior fusion was done by autogeneous bone graft. Postoperative lateral X-rays and three-dimensional computed tomography showed the physiological realignment and the correct screw placements (Fig. 2, 3). The postoperative period was uneventful without any additional complication. The post-operative hospitalization time was 7 days. The patient was discharged from the hospital with a rigid cervical orthosis. The patient's quadriparesis was improved significantly. Lower-extremity paresis was completely resolved only distal part of the upper-extremity : finger flexion, finger extension and opposition were slightly paretic. The patient was neurologically intact at the second month of the follow-up after a rehabilitation (Asia E).

The term spondyloptosis is made of spondylo and ptosis words and is used when the vertebrae slips and falls down totally in front of lower corpus from its original anatomical level4). Spondyloptosis can be frequently in the lumbar region but subaxial cervical spondyloptosis is extremely rare3,4). All of the ligamentous and osseous construction can be disrupted and the physiological alignment is discontinued due to an absolute displacement.

The etiology of the spondyloptosis in our patient was trauma. Trauma generally results in crushing the spinal cord, which could lead to severe neurological deficits such as quadriplegia. Posterior element fractures led to a spontaneous dorsal decompression of the spinal canal and this allowed the cord to move posteriorly2). This movement may preserve the spinal cord from subsequent injury as in our case. Cervical spondyloptosis can be treated conservatively or with either anterior, posterior or combined surgical approaches1,2,4). We decided to perform an anterior decompression as an initial approach to prevent spinal cord from subsequent compression from traumatic disc material. We expected a solid fusion with a combined anterior and posterior approach which restores spondyloptosis. Menku et al.3) was also suggested that three-dimensional fixation for the cervical spine using the successful placement of lateral mass and transpedicular screw fixation and rod constructs with an anterior cervical plate offer significantly increased stability over that of other conventional cervical fixation systems. But Ozdogan et al.4) indicated the possible risc of graft dislodgment that might be occured if the initial operation was done anteriorly. They advocated the posterior approach as an initial operation. Our case was completely unstable due to complete distruption of all ligamanter structures involving three columns. Therefore, realignment and stabilization of cervical spine were achieved with combined anterior and posterior approach. The patient was symptome free and neurologically intact in her second month follow-up visit.

Cervical traction can be implemented to restore anatomic alignment in preparation for stabilization. But, the role of cervical traction in cases with partial neurological deficit is still controversial. Menku et al.3) suggested that retropulsion of the disc into the spinal canal during traction could lead to compression of the spinal cord and cause neurological deterioration. However, Tumialan et al.5) reported that fractures of the posterior elements functionally decompress the spinal canal and thereby allow for cervical traction to be safely implemented in spondyloptosis patients. In the presented case, we decided to reduce the spondyloptosis with cervical traction pre-operatively and achive grade 1 spondylolisthesis then would make the anterior decompression and fusion safely without any additional neurological compromise.

Subaxial cervical spondyloptosis is a relatively rare clinical entity. Different clinical presentations in a wide range of neurologically intact to quadriplegia can be seen with spondyloptosis. The general medical and neurological status, also the wishes of the patient and the experience of the surgeon should be carefully taken into considerations in making a appropriate treatment plan.