The straightening of the normal lumbar lordosis is known as a flatback syndrome. The condition may affect patients who had prior spine surgeries or suffer from degenerative spine conditions. Flatback syndrome results in back pain, difficulty walking and standing straight. The management of flatback syndrome involves the use of conservative measures and in some patients, surgical correction may be needed.
The human spine consists of 24 vertebrae stacked upon each other to form the vertebral column. The vertebral column provides a safe conduit for the spinal cord and the numerous spinal nerves branching from the spinal cord. Each vertebra joins the adjoining vertebrae through facet joints and the intervertebral discs.
The natural vertebral column is curved in an ‘S’ shape. The neck spine is curved inwards, the thoracic spine is curved backward and the lumbar spine is curved inwards. The natural curves in the spine function to keep the center of gravity of the spine in line with the pelvis and the legs. The natural alignment thus functions to maintain the balance of the body in activities such as standing, walking, etc.
In flatback syndrome, the natural inward curve of the spine is lost and the lumbar spine is straight. The resulting alignment shifts the balance of the spine forward and causes the symptoms associated with the flatback syndrome.
Patients with flatback syndrome find it difficult to stand straight as the center of gravity shifts forward. The patients report a feeling of falling forward on walking or standing. Initially to compensate for the altered balance of the spine the patients may often bend their hips and their knees to stand straight. The back muscles contract to pull the spine back to stand straight.
Bending of the knees and hips along with constantly contracted back muscles, results in severe pain in the back and the legs. The patients may feel tired and fatigued and stoop while walking especially at the end of the day. They may use an assistive device in the form of a cane or a walker to support the body falling forward on walking.
Often patients who receive surgical treatment for scoliosis with a fusion of multiple segments end up with a flatback syndrome due to loss of natural curve. Patients having a prior surgical history of fusion of the lumbar spine or laminectomy of the lumbar spine may also develop the flat back syndrome.
Besides the history of prior surgery, the flatback syndrome may be present in certain patients due to a developmental deformity or they may be born with the condition (congenital). Patients suffering from ankylosing spondylitis in the advanced stage of disease may develop the flatback syndrome. The lumbar spine in ankylosing spondylitis becomes fused due to the ossification of ligaments and the formation of bridging syndesmophytes.
With advancing age, there may be a loss of disc height secondary to the decreased water content of the intervertebral disc and lead to degenerative changes in the vertebra. This results in loss of the natural lordotic curve of the lumbar spine that may cause the flatback syndrome. In patients with metabolic bone disease such as osteoporosis, there may be compression fractures of the vertebrae that may disturb the natural alignment of the spine and cause flatback syndrome.
The diagnosis of flatback syndrome is made by the orthopedic spine surgeon after a thorough evaluation of the patient. The evaluation consists of extraction of the history of symptoms and any prior surgical procedures. The physician conducts a thorough examination of the spine to look for the alignment and the gait of the patient. The physician also checks for the integrity of the neurological system.
The physician may request a full-length X-ray to check for the alignment of the spine. CT scan may be done for further evaluation of the bony spine and an MRI may be done to look for the soft tissue structures of the spine.
The flatback syndrome is initially managed using conservative treatment options. The conservative treatment options include physical therapy to strengthen and improve the flexibility of the back and the abdominal muscles. Gait training is done to help form a correct posture during walking.
Nonsteroidal anti-inflammatory medications and other pain medications such as Tylenol may be used to relieve the pain associated with the flatback syndrome. Heat and cold therapy may be used to reduce pain and inflammation of the lumbar spine. Epidural and nerve block injections may be used to provide pain relief and symptoms of radiculopathy.
Surgery is reserved for patients who have failed to benefit from conservative measures. The surgical treatment of flatback syndrome involves correction of the lumbar curve to align the spine. A spinal osteotomy and pedicle subtraction surgery involve cutting a wedge-shaped part of the lumbar spine to make a natural curve. The surgery usually involves the fusion of the involved vertebrae using a cage and a bone graft. The fused segment is stabilized using a screw and a rod construct on either side of the midline.
The patients treated with surgical correction techniques experience significant relief of symptoms and are quickly able to get back to their daily routines. As with any surgery, there may be risks and complications associated with corrective surgery such as bleeding, infection, blood clot formation, failure of fusion, damage to nerves/dural sac, etc. The operating spine surgeon will discuss all the potential benefits and risks before doing the surgery.