Osteotomy Of The Cervical Spine In Ankylosing Spondylitis

Abstract

Fifteen patients with ankylosing spondylitis who had developed a severe flexion deformity of the cervical spine which restricted their field of vision to their feet, were treated by an extension osteotomy at the C7/T1 level. The operation was performed under general anaesthesia with the patient in the prone position and wearing a halo-jacket. Three had internal fixation using a Luque rectangle and wiring. Their mean age was 48 years. Before operation the mean cervical kyphosis was 23 degrees; this was corrected to a mean of 31 degrees of lordosis, a mean correction of 54 degrees. All the patients were able to see straight ahead. One patient with normal neurology soon after operation became quadriparetic after one week; two others had unilateral palsy of the C8 root, which improved. There was subluxation at the site of osteotomy in four patients, and two of them developed a pseudarthrosis which required an anterior fusion.

C7 decancellisation closing wedge osteotomy for the correction of fixed cervico-thoracic kyphosis

“…There are a number of disadvantages however with this technique: (1) at the point of correction the patient is given a brief anaesthetic thereby losing subjective spinal cord monitoring, (2) lack of airway control in the event of sudden emergencies, (3) risk of air embolism, and (4) difficulty in managing hypotension. Due to the advances in fibre optic intubation and somatosensory and motor evoked potential monitoring, general anaesthesia is now favoured by the patient, surgeon and the anaesthetist [5,7,9].…”

“…Halo-jacket without internal fixation after osteotomy has been found to be inadequate for immobilisation [7,9], hence the addition of internal fixation can prevent displacement and loss of correction postoperatively. Although Shimizu et al [12] and Mc Master [7] initially used sub-laminar wires, due to the ankylosis of posterior bony elements and possibility of tearing underlying adherent dura, they are no longer used.…”

“…Although Shimizu et al [12] and Mc Master [7] initially used sub-laminar wires, due to the ankylosis of posterior bony elements and possibility of tearing underlying adherent dura, they are no longer used. Lateral mass and thoracic pedicle screws with rods have been used more recently [4,9].…”

“…Severe fixed flexion deformity of the cervical spine in patients with ankylosing spondylitis can cause significant psychological and functional disability [7]. Apart from being painful, it can cause marked limitation of the forward gaze, interfere with chewing, swallowing and skin care under the chin.…”

“…However, in patients with advanced disease causing a fixed deformity, the only treatment available is a corrective extension osteotomy [7,9].…”