Necessary cervical kyphosis correction angle (NeckCA) for ideal alignment in cervical spinal deformity

In CSD correction, increasing CL alone to meet a T1S - CL < 15° often results in compensatory increases in T1S, leading to undercorrection. To counteract this, preoperative planning should include an additional corrective angle represented by the COG-T1. The authors' analysis of 29 cases confirms the use of NeckCA as a practical and predictive parameter for achieving optimal cervical alignment.