Cervical sagittal alignment in patients with dropped head syndrome

Area of Science:

• Spine surgery
• Orthopedics
• Radiology

Background:

• Dropped head syndrome (DHS) presents as positive or negative sagittal vertical axis (SVA) types.
• Cervical sagittal alignment in DHS, including global spinal alignment, requires further clarification.
• Understanding these alignments is crucial for diagnosing and managing DHS.

Purpose of the Study:

• To characterize the cervical sagittal alignment in DHS patients.
• To analyze the relationship between cervical sagittal alignment and global spinal alignment.
• To differentiate alignment characteristics between positive and negative SVA types of DHS.

Main Methods:

• Lateral global-spine standing radiographs were analyzed for 35 DHS patients and 28 controls (cervical spondylosis).
• Patients were categorized into negative DHS (N-DHS, SVA < 0 mm) and positive DHS (P-DHS, SVA ≥ 0 mm) groups.
• Key parameters measured included C2-C7SVA, O-C2A, C2S, C2-7A, T1S, and C7SVA.

Main Results:

• Both P-DHS and N-DHS groups showed significantly larger C2-C7SVA and C2S compared to controls.
• N-DHS patients exhibited significantly smaller C2-7A and T1S compared to P-DHS patients.
• C7SVA was significantly different between the groups, notably negative in N-DHS.

Conclusions:

• Cervical sagittal alignment in DHS differs significantly between P-DHS and N-DHS.
• C2-C7SVA and C2S are consistently larger in DHS patients irrespective of type.
• P-DHS is associated with larger C2-7A and T1S, suggesting potential thoraco-lumbar imbalance considerations.