The Presence of a Negative Sacral Slope in Patients with Ankylosing Spondylitis with Severe Thoracolumbar Kyphosis

Abstract

Negative sacral slope does exist in Chinese Han patients with ankylosing spondylitis with thoracolumbar kyphosis. This appears to be caused by severe kyphosis, an initially small sacral slope, and pronounced tilting of the femoral shaft as a result of knee flexion, resulting in the pelvis becoming further retroverted.