Effect of selective and nonselective fusion on cervical sagittal alignment in Lenke 5 scoliosis

This study compares the change in cervical sagittal alignment (CSA) after surgery in Lenke 5 patients who underwent selective and nonselective fusion and to evaluate the effect of this situation on functional results.

A total of 50 Lenke 5 AIS patients who underwent posterior pedicle screw fusion between January 2015 and March 2021 were retrospectively reviewed. The patients were divided into 2 groups: selective and nonselective fusion groups. Preoperative and postoperative radiological measurements of the patients were made using the SURGIMAP (Nemaric Inc., New York) (https://www.surgimap.com/) measurement system. Clinical outcomes were evaluated with the Scoliosis Research Society-22 (SRS-22) and Neck Disability Index (NDI) questionnaires.

While cervical lordosis increases significantly in the selective group, it does not change in the nonselective group. While TK decreased significantly in the nonselective fusion group, it did not change in the selective group. C2 slope measurements show a significant decrease in the selective group in the postoperative period, and T1 slope shows a significant increase in the postoperative nonselective group. A positive, statistically significant relationship was found between the rate of change in CL measurements and the rate of change in cSVA measurements in the selective group. There is no significant difference between the SRS-22 and NDI scores of the preoperative and postoperative groups.

While postoperative C2 to C7 lordosis increased significantly in patients who underwent selective fusion, the straight of CSA did not change in the nonselective group. Since this may be a risk factor for cervical pathologies in older ages in the nonselective group, care should be taken not to reduce TK in patients with nonselective fusion.