Cervical Sagittal Alignment in Scheuermann Disease

Area of Science:

• Orthopedics
• Spine Surgery
• Radiology

Background:

• Scheuermann disease (SD) is characterized by structural hyperkyphosis, potentially affecting sagittal cervical balance.
• SD can be localized in the thoracic (SDT) or thoraco-lumbar (SDTL) spine segments.

Purpose of the Study:

• To assess and compare sagittal cervical balance in patients with SDT versus SDTL.

Main Methods:

• Retrospective evaluation of radiographs from 71 patients with SD (aged 16.3 ± 3.8 years).
• Measurements included C0-2 angle, C2-7 angle (CL), C1-C2 angle, cervical tilt (CT), thoracic inlet angle (TIA), and T1 slope.
• Statistical comparison using t-tests with a significance level of P < 0.05.

Main Results:

• SDT patients exhibited a significantly greater T1 slope (38.1° vs. 28.9°), CL (-19.8° vs. -8.9°), CT (29.8° vs. 24.3°), and TIA (81.9° vs. 71.1°) compared to SDTL patients.
• Differences in CL were primarily observed in the C6-C5 and C5-C4 segments.
• No significant differences were found in proximal cervical lordosis (C0-2, C1-C2 angles) or cranial parameters.

Conclusions:

• Scheuermann disease type significantly influences cervical sagittal balance.
• The localization of hyperkyphosis affects T1 slope, C2-C7 lordosis, cervical tilt, and thoracic inlet angle.
• Compensation occurs in the subaxial cervical spine, as evidenced by differences in C2-C7 lordosis but not C0-2 lordosis; head center of gravity position is independent of SD type.