Occipitocervical fixation in the management of craniocervical instabilities

ABSTRACT

The occipitocervical junction presents a unique, complex, biomechanical interface between the cranium and the upper cervical spine. Occipitocervical fixation has undergone significant evolution due to advances in operative techniques and instrumentation techniques. This study was done to evaluate clinical picture, radiographic findings and results of occipitocervical fusion in 10 patients with craniocervical instabilities. Also to compare these results with other results reported in the literature. This retrospective study reviewed 10 patients who underwent occipitocervical fixation for craniocervical instabilities between April 2007 and October 2010 in Alexandria hospitals. There were 7 males and 3 females and their ages ranged from 16 to 63 years with mean age of 42.1 years. As regards the clinical presentation, all patients had presented with neck pain before surgery, 8 patients [80%] with myelopathy, and 8 patients [80%] had presented with a neurological deficit either motor or sensory or both. The etiologies of occipitocervical instability in this study were trauma in three patients, rheumatoid arthritis in three patients, tumor in two patients and Down syndrome in two patients. All patients had preoperative craniocervical plain X-ray, CT and MRI examination. All patients underwent occipitocervical fixation surgery with various fixation systems and autologous bone grafts for fusion. Fusion was assessed by plain cervical X-ray films and CT scan, and the neurological outcome by Frankel grade. The mean follow-up period was 14.7 months [range, 4-24 months] including both clinical and radiological examinations. There were no operative mortalities or vascular injuries in this series. Two patients showed transient neurological deterioration postoperatively that had resolved within three months. Two cases had superficial wound infection and one case had cerebrospinal fluid leak. The mean operation time was 207 min [range 130-320 min] and the mean volume of blood loss was 354 mL [range 120-750 mL]. Neck pain improved in all patients and no new instability developed at adjacent levels. Regarding the Frankel grade, five patients had shown improvement [Three patients improved from Frankel grade C to grade D, one patient from grade A to grade B and one patient from grade D to grade E], while five patients remained stationary at the same grade. At the last follow-up examination period, a solid fusion was achieved in nine patients out of ten [90%]. Occiptocervical fixation is indicated in the management of craniocervical instabilities resulting from trauma, rheumatoid arthritis, tumors and congenital anomalies of the craniocervical junction. Accurate imaging studies and proper patient selection are the keys to a successful outcome. Occipitocervical fusion procedures can be performed with low morbidity. A comprehensive knowledge of the anatomy of the occipital-cervical junction is imperative. A wide variety of stabilization techniques and instrumentation systems are currently available, each of which has its own advantages and disadvantages