Flat Back / Fixed Sagittal Imbalance


What is flat-back / fixed sagittal imbalance?

"Flat-back" or fixed sagittal imbalance is a type of deformity where loss of the normal lordosis, or "œsway-back", of the lumbar spine causes the torso and head to pitch forward relative to the hips and pelvis. 

What causes flat-back / fixed sagittal imbalance?

Most commonly, flat-back/fixed sagittal imbalance is related to previous surgery on the spine.  Historically, Harrington-rod instrumentation was used to treat scoliosis and sometimes resulted in loss of lumbar lordosis.  Occasionally, procedures which remove bone from the back of the spine to relieve pressure on nerves can result in instability and a forward-pitched position of the spine.  Severe spondylolisthesis can also result in a fixed sagittal imbalance.

What are the symptoms?

The primary symptom of flat-back/fixed sagittal imbalance is the feeling of the upper-body and head being pitched forward on the pelvis, and this can be accentuated during walking.  Back pain and pain radiating down the legs can also be associated with flat-back/fixed sagittal imbalance.

How is flat-back / fixed sagittal imbalance diagnosed?

In addition to a complete history and physical examination, diagnostic procedures for cervical radiculopathy/myelopathy may include the following:

Treatment for flat-back / fixed sagittal imbalance

Specific treatment for sciatica will be determined by your physician based on:

To help relieve the symptoms, treatment may include:

Stanford Medicine Resources:

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