What are the causes of flat back syndrome

We all know that under normal circumstances, our spine is in an S shape. As the name suggests, flat back syndrome means that the thoracic spine of the patient has lost its normal curvature and has become a straight spine. When suffering from flat back syndrome, the patient cannot maintain a normal upright position, and even standing becomes a problem. In order to relieve spinal symptoms, many patients will use hip and knee flexion postures to maintain the position of the spine, but doing so often aggravates the condition. Now let’s talk about the causes of flat back syndrome.

1. Common causes of flat back syndrome:

1. Application of distraction devices in the lower lumbar spine and/or sacral spine

The use of distraction devices in the lower lumbar spine and (or) sacral spine is the main cause of flatback syndrome. The degree of loss of lumbar lordosis is related to the segment of fusion and internal fixation; the closer the fusion range is to the sacrum, the more serious the loss of lumbar lordosis is.

2.Thoracolumbar kyphosis

Lumbar scoliosis or thoracolumbar scoliosis is often accompanied by thoracolumbar kyphosis. The lumbar lordosis can be flattened by the distraction device, and the thoracolumbar kyphosis usually develops further proximal to the fusion site, leading to the occurrence of flat back syndrome.

3. Pseudarthrosis

Pseudarthrosis of the thoracolumbar region can lead to thoracolumbar kyphosis and thus flat back syndrome. In addition, the pain caused by pseudoarthrosis can complicate the clinical presentation of flatback syndrome. If false joint formation occurs in the lower lumbar spine or lumbosacral joint, the symptoms of lower back pain may be more obvious.

4. Others

Hip flexion contracture can aggravate the symptoms of postural deformity caused by loss of lumbar lordosis. When the hip joint is flexed and contracted, the increase of lumbar lordosis can play a compensatory role. If the lumbar lordosis disappears, this compensatory mechanism disappears and the patient cannot stand upright. Conversely, hip hyperextension can compensate for the loss of lumbar lordosis, but patients with post-polio syndrome are often unable to compensate for the loss of lumbar lordosis due to weakness of the hip flexor muscles. Another compensatory mechanism for the loss of lumbar lordosis is the extension of the thoracic spine. When the thoracic kyphosis deformity has been fixed (such as thoracic fusion), this compensatory mechanism also disappears. In addition, lumbar vertebral collapse is also one of the reasons that lead to the disappearance of lumbar lordosis.

2. Treatment:

The purpose of treatment is to relieve pain and restore the normal lumbar lordosis curve. Non-surgical treatment measures include hip flexor and back muscle training, braces and drug therapy. If the patient's symptoms are severe and conservative treatment is ineffective, osteotomy should be performed to restore lumbar lordosis.

3. Prevention:

Although the lumbar lordosis angle of flatback syndrome patients increases after surgical treatment, the symptoms of most patients cannot be completely relieved. Some patients still have forward trunk tilt, and some still have moderate to severe low back pain. In view of the poor effect of surgical treatment of flatback syndrome, the prevention of flatback syndrome should be emphasized.

When performing surgical treatment for scoliosis, the possible effects of fusion and internal fixation on the sagittal balance of the spine should be fully estimated, and efforts should be made to complete surgical correction and fusion of the spinal deformity while maintaining or restoring the sagittal balance of the spine.