The human spinal column has natural curves in specific regions of the back. These curves are either inward (toward the front of the body) or outward (toward the back of the body) and are in an alternating pattern that forms an “s” shape. The vertebrae in the neck (cervical) and lower back (lumbar) curve slightly inward, and the mid and upper back (thoracic) gently curve outward. These curves help us to maintain correct posture and balance when still and in motion.

Variations in Back Curvature

Individuals can experience changes in these normal curvatures that can range from minimal to extreme. An exaggeration of a curve inward is referred to as lordosis, and an outward curvature is known as kyphosis. However, in some instances, there is a decrease in the curvature in the lumbar area of the back that leads to what is called flat back syndrome.

Between the 1960s and 1980s, the majority of the diagnosed cases of flat back syndrome were a result of corrective spinal surgery for scoliosis. These patients had an early type of spinal implant know as a Harrington rod. These rods were used to correct the spinal deformities associated with scoliosis. This caused an unnatural straightening of the lower back and subsequent disc deterioration in the lumbar region that led to even more significant flattening. Since that time, other types of spinal rods have been developed that allow surgeons to more accurately correct deformities and reduce the risk of flat back syndrome.

Today, the medical description of flat back syndrome includes any decrease in the normal lumbar curvature that leads to the patient experiencing symptoms. These symptoms can include muscle fatigue chronic pain, difficulty standing upright, weakness/numbness of the legs and a decreased ability to perform daily tasks.

Common Causes of Flat Back Syndrome

Flat back syndrome can occur as a result of any medical condition or prior spinal surgery that shortens the anterior (toward the front of the body) portion of the spine. This syndrome can occur as a result of the following:

• Degenerative Disc Disease
• Vertebral Compression Fractures
• Lumbar Post Laminectomy Syndrome
• Any prior surgery in which the spine was fused with inadequate curvature
• Ankylosing Spondylitis
• Parkinson’s Disease

Diagnosis of Flat Back Syndrome

A physician will begin with a detailed medical history and physical examination to determine how long the problem has existed, the symptoms that are associated with it, any forms of treatment that have been attempted, any prior surgeries on the spine, all other medical conditions and any recent changes in medication, diet or level of activity.

The doctor may order additional diagnostic tests that could include x-rays, a computed tomography (CT) scan and/or a magnetic resonance imaging (MRI) to determine the degree of deformity in the back. These are necessary tests that can help the doctor determine if this syndrome is a result of a stable structural abnormality or spinal instability. The doctor will also need to determine if there is any narrowing of the spinal canal (spinal stenosis) that can cause the spinal cord or nerve roots to be pinched and can be the source of numbness, tingling, and pain.

Treatment Options for Flat Back Syndrome

Many patients that have been diagnosed with flat back syndrome can be treated effectively without non-surgical interventions. The primary types of treatment typically include a conservative approach and can include any or all of the following:

Those patients that do not respond positively to non-surgical treatments or who have structural problems and severe deformities may be a candidate for surgical intervention. Surgical procedures that are commonly used treat flatback syndrome include an osteotomy. An osteotomy involves removing a wedge-shaped piece of bone(s) at the back of the spine. When the wedge is then closed, it will increase the amount of curve or lordosis in the lower back.

Often, this surgery is performed at multiple spinal levels, depending on how much is necessary to achieve the desired correction. Surgery to correct flat back syndrome may be performed from multiple or combined approaches, and the final recommendation from the surgeon is based on a desire to create the least invasive and safest procedure for each patient.

References

https://www.sciencedirect.com/science/article/pii/S2212134X15000052

https://journals.lww.com/jbjsjournal/Abstract/2004/08000/Prevention_and_Management_of_Iatrogenic_Flatback.27.aspx

https://www.rheumatology.org/I-Am-A/Patient-Caregiver/Diseases-Conditions/Spinal-Stenosis

https://thejns.org/spine/view/journals/j-neurosurg-spine/21/2/article-p160.xml

https://thejns.org/focus/view/journals/neurosurg-focus/15/3/foc.2003.15.3.8.xml