ANTERIOR CERVICAL FIXATION FOR LESIONS OF THE SUBAXIAL CERVICAL SPINE

Abstract

This study was conducted to detennine the indications, safety, efficacy, and complication rate associated with perfonning anterior cervical decompression of neural elements and fixation by means. of plate and screws or cages. Between 1999 and 200 I, I 00 patients underwent anterior cervical decompression and fixation for different subaxial cervical spine pathologies.

In our study the male to female ratio was 2.7 to I. The average patient age at the time of presentation was 43.6 years. Ninety-two of our patients presented with a gradual onset, while 8 presented with an acute onset due to trauma. The average preoperative duration of symptoms was 22 months. A total of 71 patients had degenerative spondylosis, 24 patients had cervical disc disease, 4 patients had traumatic fracture of the cervical spine, and one patient had a mass lesion.

The most common presentation in our study was radiculopathy and was encountered in 36% of patients; radiculomyelopathy and myelopathy were •each seen t in 32% of patients. All of the patients experienced neck pain and parathesi brachialgia was present in 63% of the patients, 40% showed gait disturbances, sphincteric disturbances were present in 40% of the patients, and 40% suffered sexual troubles that ranged from weak erection to impotence. Seventy-five percent of the patients suffered from weakness; quadriparesis was noted in 39%, paraparesis in 17%, monoparesis in 15%, and hemiparesis in 4%. Dennatomal sensory affection was found in 68% of patients and a sensory level was noted in 32%, whii< long tract signs occurred in 63 % of patients.

J In our study 89% of the patients underwent anterior cervical discectomy and fixation. Eighty-one of those patients underwent fixation by means of a titanium locking plate system; 7 of these patients underwent single-level fixation, 32 patients underwent double-level fixation, 32 underwent three-level fixation and I 0 patients underwent four-level fixation. Titanium interbody cages were used in 8 patients who ) underwent anterior cervical discectomy. Carpectomy and plate fixation was done in eleven cases, 10 of which underwent double-level fixation, while only one patient underwent three-level carpectomy and four-level fixation.

Patient evaluation by radiological studies included plain cervical radiography which was done for all patients. Dynamic films were done for 96% of patients. CT was done for only 3% of the patients; those were the patients who presented to the emergency unit with fracture of the cervical spine. CT accurately diagnosed the presence of bony fragments inside the canal. Finally MRI was done for all the patients included in our study. Neuroimaging studies revealed a soft disc in 24% of the patients, osteophytes in 39%, and a combined soft and hard disc in 32%. MRI was of great advantage in revealing an abnonnal cord signal, which was present in 30% of the patients, and was an important factor in predicting the outcome.