| Objective: The aim of this research was to evaluate the curative effects of posterior decompression reduction and fixation on patients with Chiari malformation type Ⅰ(CMⅠ)and unstable basilar invagination.Methods: 15 patients with CMⅠand unstable basilar invagination,treated with posterior decompression reduction and fixation between Apr 2013 to Jan 2016 at affiliated hospital of Southwest Medical University,was selected.Of the patients,female 11 cases and male 4 cases,age from 19 to 62 years old,mean43.3 years old,the duration of disease from 1 month to more than 10 years.All patients were checked with spine /spinal magnetic resonance imaging(MRI),head and cervical 3D CT,and understood the vessel shape by angiography.All of them were with atlantoaxial dislocation and odontoid exceeding magnum.A total of 13 were with syringomyelia.We take different surgical methods,According to the clinical symptoms and imaging findings before operation.For example,if there are more than 10 mm of tonsillar hernia,or obvious bulbar degeneration.Another if MRI shows the outflow tract of four ventricle significantly narrow or complicated with hydrocephalus and the subarachnoid disappea in the focus of head and neck.Among them,6 cases were treated with reconstruction of the cisterna magna(including foramen magnum decompression,extensive duraplasty,arachnoidal adhesion lysis,and resection of the cerebellar tonsils),and 9 cases were treated with posterior fossadecompression(PFD).All the patients were treated with direct reduction and internal fixation for unstable basilar invagination.Patients were followed up to understand the recovery of symptoms after operation 1 year,and evaluated the neurological function with Japanese Orthopedic Association(JOA)score,and comprehensive evaluated the surgical effects through the related imaging parameters,like atlantodens interval(ADI),the distance of odontoid acrossing Chamberlain’s line(CL),cervicomedullary angle(CMA)and the size of syringomyelia on the maximum plane.Results: All the patients were treated with posterior decompression and fixation.There were on one neurological deterioration or death.The main symptoms :headache disappeared in 7 cases(7/10,70%),improved in 3 cases(3/7,30%);dizziness disappeared in 6 cases(6/7,85.7%),improved in 1 cases(1/7,14.3%);body weakness disappeared in2 cases(2/11,18.2%),improved in 8 cases(8/11,72.7%),no improvement 1cases(1/11,9.1%);body numbness disappeared in 4 cases,4/10,40%),improved in 6 cases(6/10,60%);Nerve function recovered well in 10(66.7%)cases,effect in 4(26.7%)cases,invalid in 1(6.7%)cases.The JOA score was increased from 10.47 to + 2.23 to 13.67±1.54 after operation,the difference was significant(P<0.05);The distance of odontoid acrossing Chamberlain’s line was decreased form 11.19 + 2.70 mm to 6.07 + 1.36 mm after operation;The atlantodens interval was decreased form 4.76 + 2.11 mm to 3.44 + 1.90 mm after operation;The cervicomedullary angle was increased from 126.43 + 7.90 degrees to 136.94 + 7.46 degrees after operation,all of them,the difference wasstatistically significant(P<0.05).Syringomyelia disappeared in 2 cases(15.4%),narrowed in 9 cases(69.2%)and no significant changed in 2 cases(15.4%)after operation.One patient with reconstruction of the cisterna magna was found wound effusion and Cerebrospinal fluid leakage,witch Wound healing through Continuous lumbar cistern drainage and Dressing.Conclusion:1.The posterior decompression reduction and fixation on patients with Chiari malformation type Ⅰand unstable basilar invagination can improve prognosis.;2.Direct reduction and internal fixation can improve the instability between atlas and axis;3.According to the clinical symptoms and imaging findings of patients with CMAI and unstable basilar invaginationbefore operation,the difference of surgical approach can not only improve the prognosis of patients,but also reduce the incidence of surgical complications;... |
