ObjectiveTo assesse the effectiveness of anterior cervical discectomy and fusion with Cage alone in treating multi-level cervical degenerative disease. MethodsBetween August 2010 and August 2012, 62 eligible patients with multi-level cervical degenerative disease were treated, and the clinical data were reviewed. Of 62 patients, 32 underwent anterior cervical discectomy and fusion with Cage alone (group A), and 30 underwent anterior cervical discectomy and fusion with plate fixation (group B). Both groups showed no significant difference in gender, age, disease duration, lesion types, and affected segments (P>0.05), it had comparability. Clinical outcomes were assessed using Japanese Orthopedic Association (JOA) score and visual analogue scale (VAS) score; the fused segment height, subsidence rates of Cages, global cervical lordosis, and fusion rates were also compared. ResultsThe operation time of group B[(109.7±11.2) minutes] was significantly more than group A[(87.8±6.9) minutes] (t=-2.259, P=0.037). Primary healing of incisions was obtained in all patients of 2 groups. All patients were followed up; the follow-up period ranged from 8 to 27 months (mean, 15.8 months) in group A, and from 9 to 28 months (mean, 16.4 months) in group B. There was no complication and internal fixation failure. The JOA score and VAS score were significantly improved at last follow-up when compared with preoperative scores in 2 groups (P<0.05). According to Robinson standard for axial symptom severity, the results were excellent in 20 cases, good in 9, fair in 2, and poor in 1, with an excellent and good rate of 90.63% in group A; the results were excellent in 19 cases, good in 7, fair in 3, and poor in 1, with an excellent and good rate of 86.67% in group B; and no significant difference was found between 2 groups (χ2=0.765, P=0.382). The fused segment height at immediate after operation and at last follow-up and global cervical lordosis at last follow-up were significantly improved when compared with preoperative ones in 2 groups (P<0.05). There was no significant difference (P>0.05) between groups A and B in the Cage subsidence height[(1.4±0.9) mm vs. (1.2±1.6) mm], Cage subsidence rate[9.52% (8/84) vs. 7.59% (6/79)], and fusion rate[95.24% (80/84) vs. 96.20% (76/79)]. ConclusionAnterior cervical discectomy and fusion with Cage alone can obtain good clinical results and radiologic indexes, avoid plate-related complications and reduce operation time. It is a safe and effective surgical option in the treatment of multi-level cervical degenerative disease.
ObjectiveTo discuss the effect of three different ways of annulus fibrosus incision on the biomechanical strength of intervertebral disc. MethodsA total of 30 goats underwent intervertebral disc nucleus pulposus extraction at L3, 4 and L4, 5 by the working channel in group A (n=10), by circular incision in group B (n=10), and by square incision in group C (n=10). The body weight, male and female ratio, age, intraoperative blood loss, and wound healing time were recorded and compared among 3 groups. The survival rate and wound healing situation were observed after operation. At 24 weeks after operation, the goats were sacrificed, MRI images were taken to observe the signal intensity of nucleus pulposus. The disc height of L3, 4 and L4, 5 was measured to calculate the loss of disc height; biomechanical test was used to assess the strength of the disc and anulus. Histological staining was also conducted to observe the repair effect at L4, 5. ResultsThere was no significant difference in body weight, male to female ratio, age, intraoperative blood loss, and wound healing time among groups (P>0.05). All goats survived to the end of the experiment. MRI examination showed decreased signal intensity in 3 groups, indicating intervertebral disc degeneration. According to modified Thompson classification method, the degree of intervertebral disc degeneration of group A was significantly higher than that of groups B and C (P<0.05), but no significant difference was found between groups B and C (P>0.05). Difference was not significant in intervertebral space height before operation among 3 groups (P>0.05). But after 24 weeks, the intervertebral space height in group A was significantly higher than that in groups B and C (P<0.05), and the intervertebral space height loss in group A was significantly lower than that in groups B and C (P<0.05). The biomechanical strength in group A was also significantly higher than that in groups B and C (P<0.05), but no significant difference was found between group B and group C (P>0.05). HE and Masson staining showed good continuity of annulus fibrosus and clear layers in group A; poor continuity of annulus fibrosus and obvious scar tissues were observed in groups B and C. ConclusionApplication of working channel may have less destruction of annulus fibrosus, it plays a positive role in the maintenance of biomechanical strength and repair of annulus fibrosus.