What is Sagittal Imbalance?
The spine has three natural curves when viewed from the side, an inward curve in the neck and lower spine called lordosis and an outward curve in the mid-back called kyphosis. Normal spine curvature keeps your head in line with your pelvis so that the stresses on your spine are well balanced. Certain medical conditions, however, affect the curvature of the spine so that the curves become too flat or too pronounced. This changes the relationship of the head and the pelvis resulting in an imbalance of the spine called sagittal imbalance.
Two important types of sagittal imbalance include:
- Flatback syndrome: This is the loss of normal lordosis or kyphosis or both, which results in a stooped posture with the head leaning forward. This results in increased stress and pain. Patients often need the assistance of a walker and daily activities are disrupted.
- Hyperkyphosis: This is an increase in the normal kyphosis of the thoracic spine. It is characterized by a curve or hump in the mid-back. The most common type of hyperkyphosis is postural hyperkyphosis which is caused by habitual poor posture such as while working on a computer. The condition is characterized by rounding of the shoulders and upper back.
Symptoms of Sagittal Imbalance
The symptoms of sagittal imbalance include:
- Pain in the lower back
- Rounding of the mid-back
- Difficulty walking
- Difficulty facing forward while in an upright position
- Difficulty performing daily tasks
- Difficulty breathing in severe cases
Causes of Sagittal Imbalance
There are various reasons why your spine can become imbalanced such as:
- Traumatic injury
- Ankylosing spondylitis (arthritis of the vertebrae resulting in fusion)
- Previous surgical spine fusion
- Degenerative spine conditions
- Congenital defect
- Idiopathic deformity
- Other neurological diseases
Diagnosis of Sagittal Imbalance
Your doctor will review your medical history, physically examine the spine deformity and assess your pain. X-rays, MRI or CT-scans are ordered to evaluate the degree of spinal imbalance.
Treatment of Sagittal Imbalance
Non-surgical treatment is not very effective when managing symptomatic sagittal imbalance so your doctor will usually recommend surgery. Depending on the cause, surgery may be minimally invasive or involve complex reconstruction. The aim of surgery is to bring about spinal balance either by enhancing lordosis or reducing excessive kyphosis.
The procedure generally involves the following steps:
- Osteotomy or removal of bone so that the spinal deformity may be corrected.
- Fixation of the spine using screws and hooks which are secured to the vertebrae and connected to rods that hold the spine in the correct alignment.
- The fusion of the vertebral bones using bone graft in the gaps created after osteotomy. Good fusion is necessary for spine stability. Factors such as smoking and obesity can hinder bone fusion.