Anterior cervical fusion with interbody cage containing beta-tricalcium phosphate augmented with plate fixation: a prospective randomized study with 2-year follow-up. The value of somatosensory- and motor-evoked potentials in predicting and monitoring the effect of therapy in spondylotic cervical myelopathy. Prospective randomized study.
A variety of bone graft substitutes, interbody cages, and anterior plates have been used in cervical interbody fusion, but no controlled study was conducted on the clinical performance of beta-tricalcium phosphate (beta-TCP) and the effect of supplemented anterior plate fixation. The objective of this prospective, randomized clinical study was to evaluate the effectiveness of implanting interbody fusion cage containing beta-TCP for the treatment of cervical radiculopathy and/or myelopathy, and the fusion rates and outcomes in patients with or without randomly assigned plate fixation. Sixty-two patients with cervical radiculopathy and/or myelopathy due to soft disc herniation or spondylosis were treated with one- or two-level discectomy and fusion with interbody cages containing beta-TCP. They were randomly assigned to receive supplemented anterior plate (n = 33) or not (n = 29). The patients were followed up for 2 years postoperatively. The radiological and clinical outcomes were assessed during a 2-year follow-up. The results showed that the fusion rate (75.0%) 3 months after surgery in patients treated without anterior cervical plating was significantly lower than that (97.9%) with plate fixation (P < 0.05), but successful bone fusion was achieved in all patients of both groups at 6-month follow-up assessment. Patients treated without anterior plate fixation had 11 of 52 (19.2%) cage subsidence at last follow-up. No difference (P > 0.05) was found regarding improvement in spinal curvature as well as neck and arm pain, and recovery rate of JOA score at all time intervals between the two groups. Based on the findings of this study, interbody fusion cage containing beta-TCP following one- or two-level discectomy proved to be an effective treatment for cervical spondylotic radiculopathy and/or myelopathy. Supplemented anterior plate fixation can promote interbody fusion and prevent cage subsidence but do not improve the 2-year outcome when compared with those treated without anterior plate fixation. A 2-year follow-up prospective randomized electrophysiologic and clinical study of patients with spondylotic cervical myelopathy.
                To assess the value of somatosensory- and motor-evoked potentials in the evaluation and prediction of the effect of therapy.
                Previous studies have yielded conflicting data concerning the correlation between the changes in evoked potential parameters and the clinical postsurgical outcome in spondylotic cervical myelopathy.
                Sixty-one patients with magnetic resonance images suggesting spondylotic cervical cord compression and clinical signs of cervical myelopathy were divided into two groups according to the degree of clinical cervical cord involvement. The 49 patients with mild and moderate spondylotic cervical myelopathy were randomized into groups that underwent either surgical or conservative therapy. Patients were evaluated clinically and by the means of somatosensory- and motor-evoked potentials.
                The clinical and evoked potential changes showed good correlation on the group level, but poor correlation intraindividually. There were no significant evoked potential and clinical group changes after 6 months and 2 years in the mild myelopathy group treated either surgically and conservatively, whereas patients with severe myelopathy displayed significant improvement in clinical and evoked potential parameters after surgery. In a subgroup of patients, the isolated segmental medullar N13 abnormality could potentially predict favorable postsurgical clinical outcome.
                Longitudinal evoked potentials showed limited use for evaluating the results of therapy in an individual patient. They could be useful in the group assessment of therapy results and in labeling a subgroup of patients with potentially favorable postsurgical outcome.
Both small trials had significant risks of bias and do not provide reliable evidence on the effects of surgery for cervical spondylotic radiculopathy or myelopathy. It is unclear whether the short-term risks of surgery are offset by long-term benefits. Further research is very likely to have an impact on the estimate of effect and our confidence in it.
There is low quality evidence that surgery may provide pain relief faster than physiotherapy or hard collar immobilization in patients with cervical radiculopathy; but there is little or no difference in the long-term.
There is very low quality evidence that patients with mild myelopathy feel subjectively better shortly after surgery, but there is little or no difference in the long-term.