Analysis Of Sagittal Alignment Parameters Following Anterior Cervical Hybrid Decompression And Fusion Of Multilevel Cervical Spondylosis

Objectives:To investigate the relationships between sagittal alignment parameters and the relationships between sagittal alignment parameters and health-related quality of life scores following Anterior cervical hybrid decompression and fusion?ACHDF?of multilevel cervical spondylosis,and to study the significance of T1 slope?T1s?.Methods:A total of 42 patients with complete radiographic measurements following ACHDF in the Spinal Surgery Department of the First Affiliated Hospital of Fujian Medical University from August 2014 to January 2017 were retrospectively analyzed.Radiographic measurements included:C_2-7 Cobb angle,T1 slope?T1s?,C_2-7sagittal vertical axis?SVA?,cervical tilting and cranial tilting.The neck disability index?NDI?was used to evaluate the clinical prognosis and the quality of life of patients at pre-operation and follow-up.Spearman correlation coefficient was calculated between changes of radiographic measures.Linear regression analysis was used to analyze the relationships between postoperative cervical sagittal parameters and NDI.Results:In postoperation cervical sigittal alignment parameters,T1s positively correlated with C_2-7 Cobb angle?r=0.334?,C_2-7 SVA?r=0.374?,cranial tilting?r=0.478?and cervical tilting?r=0.325?.C_2-7 SVA positively correlated with cranial tilting?r=0.873?and negatively correlated with cervical tilting?r=-0.556?.Cranial tilting negatively correlated with cervical tilting?r=-0.511?.Pre-operation NDI scores positively correlated with pre-operation T1s?r=0.413?,follow-up NDI scores positively correlated with 3 month post-operation T1s?r=0.534?.Results of the regression analysis indicated that a pre-operation T1s value of 42.36°corresponded to a pre-operation NDI scores value of 25.A 3 month of post-operation T1s value of48.61°corresponded to follow-up NDI scores value of 25.The preoperative and postoperative C_2-7SVA were statistically significant?P<0.05?,increasing from?1.37±1.41?cm to?1.73±1.23?cm,cranial tilting were statisticall significant?P<0.05?,increasing from?5.53±6.33?°to?7.57±7.38?°.The preoperative and follow-up NDI score were statistically significant?P<0.01?,decreasing from 17.5±8.8 to 9.6±8.4.Conclusion:This study showed that 1.The ACHDF could signifcantly improve the health-related quality of life,and it is a kind of effective and safe surgery.2.The sagittal alignment parameters following ACHDF were closely correlated with the patient's clinical prognosis and the quality of life.Particularly,a pre-operation T1s is greater than 42oor 3 month of post-operation T1s is greater than 48ocorresponded to severe disability?NDI>25?and positive cervical sagittal malalignment.3.The sagittal balance of cervical spine significantly changes after ACHDF,it could increase cervical neural foraminal areas,and improve patient's clinical symptoms.