Anterior Cervical Discectomy and Fusion Alters Whole-Spine Sagittal Alignment

• Published in: Yonsei medical journal 2015, 56(4), , pp.1060-1070
• Main Authors: Kim, Jang Hoon, Park, Jeong Yoon, Yi, Seong, Kim, Kyung Hyun, Kuh, Sung Uk, Chin, Dong Kyu, Kim, Keun Su, Cho, Yong Eun
• Format: Article
• Language: English
• Subjects: Adult; Aged; Cervical Vertebrae - diagnostic imaging; Cervical Vertebrae - physiopathology; Cervical Vertebrae - surgery; Cross-Sectional Studies; Diskectomy; Female; Humans; Lordosis - etiology; Lordosis - surgery; Magnetic Resonance Imaging; Male; Middle Aged; Neck - surgery; Original; Radiography; Retrospective Studies; Spinal Diseases - complications; Spinal Diseases - diagnostic imaging; Spinal Diseases - physiopathology; Spinal Diseases - surgery; Spinal Fusion - methods; Spine; Treatment Outcome; Young Adult; 의학일반
• ISSN: 0513-5796; 1976-2437
• DOI: 10.3349/ymj.2015.56.4.1060

Anterior cervical discectomy and fusion (ACDF) has become a common spine procedure, however, there have been no previous studies on whole spine alignment changes after cervical fusion. Our purpose in this study was to determine whole spine sagittal alignment and pelvic alignment changes after ACDF. Forty-eight patients who had undergone ACDF from January 2011 to December 2012 were enrolled in this study. Cervical lordosis, thoracic kyphosis, lumbar lordosis, sagittal vertical axis (SVA), and pelvic parameters were measured preoperatively and at 1, 3, 6, and 12 months postoperatively. Clinical outcomes were assessed using Visual Analog Scale (VAS) scores and Neck Disability Index (NDI) values. Forty-eight patients were grouped according to operative method (cage only, cage & plate), operative level (upper level: C3/4 & C4/5; lower level: C5/6 & C6/7), and cervical lordosis (high lordosis, low lordosis). All patients experienced significant improvements in VAS scores and NDI values after surgery. Among the radiologic parameters, pelvic tilt increased and sacral slope decreased at 12 months postoperatively. Only the high cervical lordosis group showed significantly-decreased cervical lordosis and a shortened SVA postoperatively. Correlation tests revealed that cervical lordosis was significantly correlated with SVA and that SVA was significantly correlated with pelvic tilt and sacral slope. ACDF affects whole spine sagittal alignment, especially in patients with high cervical lordosis. In these patients, alteration of cervical lordosis to a normal angle shortened the SVA and resulted in reciprocal changes in pelvic tilt and sacral slope.