Neurosurgery Resident Physician Dell Medical School at The University of Texas at Austin
Introduction: The purpose of this study was to investigate the effect of Thoracic Inlet Angle (TIA) on other cervicothoracic parameters and patient reported outcomes (PROs) in patients undergoing multi-level posterior cervicothoracic fusions with a caudal end of C7, T1 or T2.
Methods: Retrospective, multi-center analysis of patients undergoing multilevel posterior cervicothoracic fusions terminating at C7, T1 or T2.
Results: 257 patients were included in this analysis. Mean age was 62.6 ± 13.4 years with a mean BMI of 28.5 ± 6.6 and 68.5% female. 57% were never smokers, 32.1% were former smokers and 10.9% were current smokers. From preop to 2years postop, there was a 2.3% change in TIA, 17.2% change in cervical lordosis, 14.1% change in T1 slope and 34.9% change in cSVA. VAS and ODI saw 31.2% and 17.2% improvement, respectively, over this time frame. There was a strong positive correlation between TIA and T1 slope at both pre (r2=56.4) and 2 years postop (r2=58.4). Similar findings were observed between TIA and cSVA at pre (r2=58.3) and 2 years postop ( r2=63.4). Weak positive correlations were observed between TIA and cervical lordosis, and PROs (VAS and ODI) and TIA at pre and 2 years post.
Conclusion : TIA remained essentially unchanged from pre- to post-op. That said, strong positive correlations were found between TIA and T1 slope and TIA and cSVA at preoperative and 2 years postoperative. The findings of this analysis support the relationship of TIA and cervical sagittal alignment demonstrated in previous studies. Additionally, weak positive correlations between TIA and cervical lordosis and TIA and patient reported outcomes were also found. Current data suggest that surgical goals include achievement of reasonable sagittal balance. More static measures such as TIA and more potentially variable measures such as T1 slope should be considered when planning a posterior cervical reconstruction.