Evaluation of Different Modalities of Anterior Cervical Discectomy for Treatment of Single and Double Level Cervical Disc Herniation

Abstract

Introduction: Cervical disc herniation and degenerative disease of the cervical spine are the most common causes of cervical cord and nerve root dysfunction. The surgical treatment of cervical radiculopathy is still controversial. Instead of two possibilities, nowadays three possible treatments concur with each other: anterior cervical discectomy without implantation of any structure, anterior cervical discectomy with fusion, and finally, cervical discectomy with implantation of disc prosthesis. Patients and methods: Twenty patients with cervical disc herniation with radiculopathy, which had not responded to conservative treatment were treated by anterior decompression and cervical disc replacement. All these patients were evaluated preoperatively clinically and radiologically (plain X-rays of cervical spine; A-P, Lateral and dynamic films: flexion, extension and oblique and MRI cervical spine). Nerve conduction study was done to exclude peripheral compression neuropathy and to confirm radiculopathy in selected cases where double entrapment phenomena suspected and followed up for a period of 1 month to 12 months. The technique followed anterior decompression differed according to the way of reconstruction at each level and the patients were accordingly classified into three groups: group A (1-level fusion); where the anterior decompression was accomplished by single level cervical discectomy, and then insertion of cervical cage at this leve, group B (2-level fusion); where the anterior decompression was accomplished by double level cervical discectomy, and then insertion of cervical cage at both levels, group C (hybrid construct); where the anterior decompression was in the form of one level cervical discectomy, followed by cage implantation at this level and another level cervical discectomy followed by insertion of cervical disc prosthesis at the same time. Functional outcome was assessed according to Odom’s criteria. Postoperative plain X-rays of cervical spine (A-P and Lateral) were done at follow-up visits (immediate postoperative, 3 months, 6 months 12 month postoperatively. MRI or CT of the cervical spine is done for patients routinely and for patients not improving or with persistent preoperative complaint or any new neurologic deficit. Results and Discussion: The ages in our patient population ranged from 30 to 50 years, with a mean of 40 ± 5.9 years (mean ± standard deviation). 11/20 patients (55%) were males, and 9/20 (45%) were females. The commonest level affected is C5-C6 level. The most common complaint of patients is neck pain and radiculopathy. Anterior cervical discectomy followed by single level cervical fusion was done on 13 patients, while 5 patients were subjected to anterior cervical discectomy followed by double level cervical fusion and another 2 patients had anterior cervical discectomy followed by cervical artificial disc replacement at one level and zero profile implant insertion and fusion at another level. Regarding the mean duration of hospital stay it was 2.4 days in the single level group while it was 3.8 days in the double level group and 4 days in the hybrid group. Regarding the functional outcome 9 patients (69.2%) had excellent outcome in the single level group versus 3 patients (60%) In the double level group and 2 patients (100%) in the hybrid group, while there were 3 patients (23.1%) who had good outcome in the single level group and 1 patient (20%) in the double level group, finally only one patient in the single level group and 1 patient in the double level group who had satisfactory outcome. There were 2 complications in this study, one (7.7%) in the single level group and one (20%) in the double level group. In the single level group 1 patient had removal of prosthesis due to device failure and hypermobility. In the double level group, one patient had temporary dysphagia and dysphonia. Conclusion: Ideal treatment for cervical degenerative disc disease must deal with and improve its three components (axial neck pain, radiculopathy, and myelopathy), normalize cervical spine biomechanics so not to act as a nidus accelerating the degenerative process, and improves the functional outcome of the patient without serious complications. CDR and ACDF are both effective treatment strategies for managing degenerative conditions of the cervical spine. There is insufficient evidence to show which technique is the most effective and provides the longest-lasting symptom relief.