Clinical efficacy of TARP for treatment of basilar invagination with syringomyelia: a report of 32 cases

English Keywords:Basilar invagination  Syringomyelia  Transoral atlantoaxial reduction plate  Internal fixation  Clinical efficacy

English Abstract:

  【Abstract】 Objectives: To investigate the effect of transoral atlantoaxial reduction and plate internal fixation for the treatment of basilar invagination with syringomyelia. Methods: From March 2005 to July 2011, 75 cases with basilar invagination were treated surgically. Of them, 35 patients were combined with syringomyelia, 32 cases of whom were followed up. There were 9 males and 23 females, aged from 23 to 74 years, with the course of disease of 6 to 372 months. 12 cases presented with Arnold-Chiari malformation, 7 cases with atlantoaxial dislocation, 1 patient with atlantooccipital fusion, 2 patients with cervical spondylosis and 1 patient with Klippel-Feil syndrome. All patients had signs and symptoms of spinal cord dysfunction, and the preoperative JOA score was 3-15 points. According to ASIA scale, there were 4 cases with grade B, 8 grade C, 20 grade D. Preoperative brainstem spinal cord angle was 123.3°±6.4° and syringomyelia size was 0.10~15.10cm3. All cases underwent TARP instrumentation, the postoperative improvement of neurofunction, brain stem spinal cord angle were recorded. The postoperative complications, follow-up changes in syringomyelia and bone graft fusion were also recorded. Results: All patients had successful surgery, with no neurovascular injury. After operation, 1 patient complained of neck discomfort, 2 cases complained of throat discomfort, which wereresolved after corresponsive treatment; 1 case had incision infection, which healed by removal of anterior instrument and posterior instrumentation; the remaining patients presented with no complication. The post-operative brainstem spinal cord angle recovered to 145.6°-165.3°, with an average of 161.3°±5.1°; JOA score improved to 10 to 16 points(average, 13.8±1.8), with an average improvement rate of 58.1%. 15 cases had ASIA scale improved. After 1 year, syringomyelia size of 30 cases shrank or disappeared, syringomyelia size of 1 case remained unchange, 1 case had syringomyelia size extended. No instrument failure was noted and all patients got bony fusion. Conclusions: Transoral atlantoaxial reduction and plate internal fixation for basilar invagination complicated with syringomyelia can not only reduce the odontoid to a physical position, but also decrease the syringomyelia size, which can relieve the clinical symptoms, but its long-term efficacy needs further observation.