Orthopaedic Spine Center
450 Broadway St. | MC6342
Redwood City, CA 94063
For Adult Patients: (650) 725-5905

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 “sway-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:

  • x-ray - a diagnostic test which uses invisible energy beams to produce images of bones onto film.
  • computed tomography scan (Also called a CT or CAT scan.) – a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs.
  • magnetic resonance imaging (MRI) - a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body; can often determine damage or disease in an intervertebral disc, vertebral body, spinal cord, nerve roots, ligaments, and muscle.

Treatment for flat-back / fixed sagittal imbalance

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

  • your age, overall health, and medical history
  • extent of the disease
  • your tolerance for specific medications, procedures, or therapies
  • expectations for the course of the disease
  • your opinion or preference

To help relieve the symptoms, treatment may include:

  • nonsteroidal anti-inflammatory medications
  • physical therapy
  • bracing
  • if symptoms persist or worsen, surgery to fuse the spine in a more balanced position may be suggested by your surgeon.