The importance of preoperative T1 slope for determining proper postoperative C2–7 Cobb’s angle in patients undergoing cervical reconstruction

Abstract

Background This study aimed to explore the relationship among different cervical sagittal parameters in asymptomatic volunteers and the correlation between surgical efficacy and difference of presumed and actual postoperative C2–7 Cobbs’s angle (C2–7COBB), which was calculated based on preoperative T1 slope (T1S) in patients undergoing cervical reconstruction. Methods In total, 158 inpatients with cervical spondylosis and 274 asymptomatic volunteers were retrospectively reviewed. Cervical sagittal parameters, such as C2–7COBB, T1S, thoracic inlet angle (TIA), and neck tilt (NT), were compared. Then, the correlation among these parameters was analyzed in asymptomatic volunteers, and a regression equation between T1S and C2–7COBB was established and used to analyze the correlation among the Japanese Orthopaedic Association (JOA) score improvement, the sagittal parameters, and the difference between presumed and actual postoperative C2–7COBB in patients after cervical reconstruction. Results The mean T1S, C2–7COBB, and TIA were significantly decreased in patients (P < 0.01). T1S and NT had a strong correlation with TIA (P < 0.01). T1S demonstrated a moderate correlation with C2–7COBB in asymptomatic volunteers (r = 0.569, P < 0.01). A regression equation had been established as C2–7COBB = 0.742 × T1S − 0.866. The mean C2–7COBB and JOA score improved significantly (P < 0.05) postoperatively. Moreover, the JOA improvement rate showed a significant negative correlation with the difference in the presumed and actual postoperative C2–7COBB (r = − 0.696, P < 0.01). Conclusion Our study successfully established a regression equation for calculating postsurgical C2–7COBB based on the correlation between T1S and C2–7COBB in asymptomatic volunteers. The regression equation could be used for guiding surgeons to accomplish an ideal postsurgical C2–7COBB for patients with cervical spondylosis.

Retrospective Analysis of Sagittal Balance Parameters and Clinical Efficacy After Short-Segment Anterior Cervical Spine Surgery with Different Fusion Devices

“…Cervical lordosis is influenced by thoracic kyphosis; thus, the TIA and T1S have also been introduced to evaluate the stability of the cervical spine. 17 Recent research has suggested that a high T1S is a potential risk factor for the development of MC due to impaired sagittal balance, especially in the C5-C6 cervical segment. 18 Therefore, in this study, we performed further analysis of the preoperative, postoperative and follow-up TIA and T1S.…”

The Difference of Sagittal Correction of Adult Subaxial Cervical Spine Surgery According to Age: A Retrospective Study

“… 11 It's defined in different ways, like local angle, cervical curvature, and cervical relative offset position, and is not easy to grasp in practice. 1 , 3 , 12 , 13 , 14 But distinct age differences have been observed in cervical sagittal alignment, and it is one of the key risk factors influencing the cervical sagittal alignment. 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 So, we propose a reconstruction algorithm for cervical sagittal alignment based on age difference.…”

“…The aims of surgical treatment are to completely alleviate the compression of dural sac, reconstruct the stability of the cervical spine, and restore the curvature of the cervical spine in accordance with the biomechanical characteristics. 2 , 3 , 4 Decompression and stabilization have been recognized surgical goals, and the techniques are generally well‐established. With the research progresses of sagittal balance, it is taken more and more seriously for cervical sagittal alignment.…”

“…suggested that cervical lordosis or neutral alignment should be restored. 3 Dennis et al . believed that it should not be forced to correct cervical lordosis, and the goal of sagittal correction should be personalized.…”

“…We make it mainly based on the experience of the surgeon and the existing references from literature, and great differences exist in clinical practice. 1 , 3 , 12 , 13 , 14 Moreover, distinct age differences are observed in cervical sagittal alignment. 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 The sagittal correction for subaxial cervical spine surgery with respect to age differences needs further study.…”