Effect analysis of modified anterior cervical discectomy and fusion in patients with degenerative cervical kyphosis

English Keywords:Degenerative cervical kyphosis  Anterior trans-intervertebral space decompression and fusion  Deformity correction  Clinical efficacy

English Abstract:

  【Abstract】 Objectives: To investigate the clinical efficacy of anterior trans-intervertebral space decompression and fusion(ATIDF) in the treatment of degenerative cervical kyphosis. Methods: The clinical data of 65 patients with degenerative cervical kyphosis who received ATIDF surgery in our department from June 2017 to June 2019 were retrospectively analyzed. There were 37 males and 28 females. The mean age was 63.4±11.2 years(35-85 years), and the mean course of disease was 18.2±8.4 months(4-28 months). 16 patients(7 patients C3-C5, 9 patients C4-C6) received two-segment ATIDF, 38 patients(18 patients C3-C6, 20 patients C4-C7) received three-segment ATIDF, and 11 patients received four-segment ATIDF(C3-C7). Among the included patients, 35(53.85%) had rigid kyphosis and 30(46.15%) had flexible kyphosis. All the patients with rigid kyphosis underwent partial uncovertebral joint excision during decompression. Japanese Orthopaedic Association(JOA) score, neck disability index(NDI) and visual analogue scale(VAS) score were used to evaluate the symptoms and neurological function of the patients before surgery, on day 2 after surgery and at final follow-up. Cervical curvature(C2-C7 Cobb angle), surgical level Cobb angle, and surgical level intervertebral height were measured on anteroposterior and lateral and dynamic cervical radiographs, and the correction rate of kyphosis was calculated. Nerve decompression and bone graft fusion were evaluated by plain MRI and CT of cervical spine. The occurrence of related complications during the follow-up period was recorded. Results: The mean follow-up time of included patients was 33.5±5.4 months(24-50 months). The average operation time was 158.2±31.4min(105-215min), and the average intraoperative blood loss was 117.6±36.3ml(65-200ml). All included patients achieved satisfactory neurological function improvement, and JOA score, NDI score and VAS score were significantly improved after surgery and at final follow-up. The postoperative kyphosis angle of cervical spine in all patients improved to some extent, and the kyphosis correction rate was 147.43%. The C2-C7 Cobb angle and the local Cobb angle of the operative segment were significantly increased on day 2 after surgery and at final follow-up, and the sagittal vertical axis(SVA) was significantly improved than before operation. The mean intervertebral height at the operative level increased from 2.14±1.53mm before surgery to 5.36±2.47mm at the final follow-up(P=0.001). During the follow-up period, 8 patients(12.31%) developed cervical axial symptoms, 33 patients(50.77%) complained of dysphagia on the second day after surgery, and 3 patients(4.62%) developed C5 nerve root paralysis, all of which were improved after symptomatic management. Conclusions: ATIDF can achieve satisfactory clinical efficacy and correction of kyphosis in treating degenerative cervical kyphosis, which also has good orthopedic and decompression effects for stiff cervical kyphosis with severe intervertebral stenosis and uncovertebral joint hyperplasia.