Comparison Of Anterior Techniques In Cervical Sagittal Alignment Of Patients With Double-segment Cervical Spondylotic Myelopathy

Objective:To determine the C2-C7 Cobb angle?C2-C7 SVA?T1 slope change after anterior cervical corpectomy with fusion(ACCF)or anterior cervical discectomy with fusion(ACDF)of double-segment cervical spondylotic myelopathy.Methods:This study includes 41 patients who underwent anterior cervical corpectomy with fusion or anterior cervical discectomy with fusion of double-segment cervical spondylotic myelopathy from Jan 2013 and Dec 2016 in department of orthopaedics,the first affiliated hospital of Guangzhou university of chinese medicine.The patients' gender,age were recorded before the operations.Then,the patients' C2-C7 Cobb angle?C2-C7 SVA and T1 slope were recorded and compared after the operations.Results:41 subjects were included of whom 21 subjects were underwent ACCF and20 subjects were ACDF,all subjects got bony union at the final follow-up.In ACCF group,14 male and 7 female,the average age was 54.5y,the average follow up time was 10.19 mon.There were 11 male and 9 female,the average age was 51.9y,the average follow up time was 9.05 mon in ACDF group.There was no significant difference in baseline data between the two groups(p>0.05).The preoperative C2-C7 Cobb angle?C2-C7 SVA and T1 slope of ACCF group were 12.64±8.98°?1.89±1.39cm?26.51±7.73°and 9.07 ± 14.50 ° ? 1.92 ± 1.16 cm ? 24.47 ± 8.32 ° in ACDF group,respectively.There was no significant difference in preoperative sagittal parameters between the two groups(p>0.05).The postoperative C2-C7 Cobb angle?C2-C7 SVA and T1 slope of ACCF group were 16.93±8.01°?1.19±1.06cm?26.43±6.94°and 23.01±8.45°?0.92±1.07cm?25.63±7.16°in ACDF group,respectively.There was a significant difference in postoperative vs preoperative C2-C7 Cobb angle?C2-C7 SVA both two groups(p<0.05),but not with T1S(p>0.05).There was a significant difference in postoperative C2-C7 Cobb angle and the change of C2-C7 Cobb angle between ACCF group and ACDF group(p<0.05),but other sagittal parameters were not.Conclusion:Both ACCF group and ACDF group could modify the cervical sagittal parameters.As to cervical spondylotic myelopathy,cervical sagittal parameter may not a main basis,but should according to surgical technique of surgeon,degree of decompression and fusion rate comprehensively.