Chiari malformation (CM) is a group of congenital cerebellar tonsillar hernia malformations involving the craniocervical junction. Chiari malformation type I (CMI) is the most common in clinic, however its pathogenesis is still unclear, and there is no consensus on the surgical treatment standard of CMI. At present, the most widely accepted is the theory of posterior fossa incompatibility, so doctors at home and abroad use posterior fossa decompression (PFD) and posterior fossa compression with duraplasty (PFDD) as the gold standard for surgical treatment, and have their own experience and technical improvement. However, the volume of the posterior cranial fossa in some patients is no different from that in healthy people, and about 30% of the patients with CMI have poor results after posterior cranial fossa decompression. As a result, this operation cannot treat all patients with CMI. In recent years, with the development of imaging, the progress of diagnostic technology and the deepening of understanding of CM, some studies have shown that CMI may be related to atlantoaxial instability, and proposed that CMI is the secondary factor of atlantoaxial instability, and atlantoaxial fusion is the standard of surgical treatment, which has caused great controversy in academic circles. Different clinical research results of scholars support or oppose this theory: some studies have shown that the clinical symptom relief rate of patients with CMI treated with atlantoaxial fusion is 96.9%; another study showed that 70% of patients with CMI underwent atlantoaxial fusion had improved neurological function, but the overall postoperative effect was not satisfactory. In short, CMI is related to many diseases and its clinical manifestations are complex. Therefore, individualized management and treatment should be carried out in combination with the clinical manifestations and auxiliary examination results of patients.

Objective:To analyze the application and clinical efficacy of one-stage unilateral or bilateral fenestration, debridement, interbody fusion combined with posterior internal fixation for the treatment of lumbosacral brucellosis spondylitis.Methods:All patients with lumbosacral brucellosis spondylitis were retrospectively analyzed, who underwent fenestration, debridement, interbody fusion combined with posterior internal fixation from June 2013 to June 2019. A total of 48 patients were enrolled in this study. According to the surgical method, they were divided into two groups. Unilateral fenestration group: 27 cases of one-stage posterior unilateral fenestration, debridement, interbody fusion combined with posterior internal fixation were performed, 21 males and 6 females, aged 23-71 years; Bilateral fenestration group: 21 cases of one-stage posterior bilateral fenestration, debridement, interbody fusion combined with posterior internal fixation were performed, aged 26-58 years. There were 16 males and 5 females. The preoperative and postoperative clinical symptoms, neurological function, C-reactive protein, the surgery duration time, the blood loss, and erythrocyte sedimentation rate were observed. The internal fixation device was evaluated for looseness or fracture by imaging examination. The Bridwell classification criteria were used to evaluate the bone graft fusion. Postoperative complications were also assessed.Results:All patients completed the operation successfully, and the diseased tissues were sent for pathological examination during the operation, and all of them were diagnosed as brucellosis. All patients were followed up for 12-48 months (mean 23.7 ±6.3 months). C-reactive protein, erythrocyte sedimentation rate, Visual Analogue Scale (VAS), Oswestry Disability Index (ODI) and Japanese Orthopaedic Association Scores (JOA) were significantly improved in both groups at different time points after operation. There was no significant difference in the general condition before operation between the two groups ( P>0.05). The mean operation time and mean blood loss were 120.5±34.1 min and 214.4±150.2 ml, in the unilateral fenestration group; 187.1±30.3 min and 455.8±250.5 ml in the bilateral fenestration group; and the difference was significant ( t=8.123, t=2.962, P<0.05) . The postoperative lumbar and leg pain were significantly relieved. There was no significant difference in C-reactive protein, erythrocyte sedimentation rate, VAS, ODI and JOA scores between the two groups at the same time point. In the bilateral fenestration group, one patient developed incision infection half a month after the operation, who underwent debridement and drainage, and finally cured. There was no significant difference in the time of bone graft fusion between the two groups ( t=0.542, P>0.05). At the last follow-up, all the patients were completely fused. Conclusion:Unilateral or bilateral fenestration, debridement and bone graft fusion and internal fixation for the treatment of lumbosacral brucellosis spondylitis can achieve good clinical results, and the former has the advantages of short operation time and low cost.

Objective:To investigate the relationship between simple Chiari malformation type I (CMI) and atlantoaxial instability from the imaging point of view.Methods:A retrospective analysis were performed on 46 patients diagnosed with simple CMI from January 2014 to December 2020. Forty-six normal people matched for age and sex were selected as the normal control group, while 30 patients with atlantoaxial dislocation were selected as the dislocation group. The degree of atlantoaxial joint degeneration in each group was assessed according to Weishaupt degeneration grading; the atlantoaxial joint angulation angle was measured in the control group of patients with simple CMI; and the sagittal imaging parameters of cervical spine X-ray were measured, including C 0-C 1 Cobb angle, C 0-C 2 Cobb angle, C 1-C 2 Cobb angle, C 1-C 7 Cobb angle, C 2-C 7 Cobb angle, C 7 Slope, C 2 Tilt, spino cranial angle (SCA), and C 2-C 7 sagittal vertebral axis (SVA). All radiographic parameters were measured twice independently by two spine surgeons, and intraclass correlation coefficient (ICC) were determined to demonstrate intra- and inter-observer reliability. Results:ICC ranged between 0.842 and 0.974 in the current study, demonstrating "excellent" reliability of radiographic measurements. No significant difference was noted regarding age and the distribution of genders among the three groups. There were significant differences in the distribution of Weishaupt degeneration grading of atlantoaxial joints between simple CMI, normal and dislocation group ( H=53.68, P<0.001 on the left side; H=43.39, P<0.001 on the right side). There were significant differences in the degree of atlantoaxial joint degeneration between the normal group and dislocation group (left, Z=6.60, P<0.001; right, Z=6.29, P<0.001); There were significant differences in the degree of atlantoaxial joint degeneration between the normal group and simple CMI patients (left, Z=5.31, P<0.001; right, Z=4.13, P<0.001); There were significant differences in the degree of atlantoaxial joint degeneration between simple CMI and dislocation group (left, Z=3.20, P=0.001; right, Z=3.15, P=0.002). There were significant difference in the angulation angle of the atlantoaxial articular surface between the normal group and simple CMI patients (left, Z=3.32, P<0.001; right, Z=5.74, P<0.001). There were significant differences in C 0-C 1 Cobb angle ( t=2.41, P=0.018), C 1-C 7 Cobb angle ( t=2.88, P=0.005), C 2-C 7 Cobb angle ( t=3.29, P=0.001), and C 2-C 7 SVA ( t=2.87, P=0.005) between the normal group and simple CMI patients, but there was no significant difference in other parameters. Conclusion:The degree of atlantoaxial joint degeneration in patients with simple CMI is higher than that in normal people, the angulation angle is larger, and the cervical lordosis is larger, suggesting that there may be atlantoaxial joint instability. This study provides further evidence that Chiari malformation type I is associated with atlantoaxial instability.