The Effect of Age on Cervical Sagittal Alignment: Normative Data on 100 Asymptomatic Subjects

Abstract

STUDY DESIGN: Retrospective study. OBJECTIVE: To determine age-related changes in cervical sagittal alignment using whole-spine standing radiographs in asymptomatic adults. SUMMARY OF BACKGROUND DATA: Modern surgical techniques have emphasized the importance of maintaining proper sagittal alignment. But there is a paucity of literature investigating age-related changes in cervical sagittal alignment. METHODS: One hundred healthy unoperated adults who were free of spinal problems obtained whole-spine standing radiographs. They consisted of 2 groups divided by age: those in their 20s and those older than 60 years. Each group had an equal ratio of males and females. Distances from C2 as well as C7 plumb lines to the following points were measured: thoracic and lumbar apex as well as the posterior superior corner of the S1 vertebral body. In addition, Cobb angles for C0-C2, C2-C7, thoracic kyphotic angle, lumbar lordotic angle, and T1 sagittal slope angles were measured. RESULTS: The distance between the C2 and C7 plumb lines did not vary with age. The thoracic apex shifted caudally from T6 in the younger group to T7 in the older group. The most common lumbar apex was L4 for both groups. The distance from C2, as well as C7 plumb lines to the posterior superior corner of the S1 vertebral body, as well as the thoracic apex increased significantly in the older group. On the contrary, the distance from the 2 plumb lines to the lumbar apex decreased in the older group. Also, C2-C7 angle increased and T1 sagittal slope angle decreased in the older group compared with the younger group. However, no difference was found for the other Cobb angles between the 2 groups. CONCLUSION: The distances between the plumb lines from C2 and C7 were maintained but C2-C7 sagittal angle increased with aging.