The spine has a series of normal curves when viewed from the side. These curves help to better absorb the loads applied to the spine from the weight of the body. The cervical spine (neck) and lumbar spine (lower back) are have a normal inward curvature that is medically referred to as lordosis . The thoracic spine (upper back) has a normal outward curvature that is medically referred to as kyphosis. In this discussion, the term kyphosis will be used to discuss abnormal kyphosis. The normal curves of the spine allow the head to be balanced directly over the pelvis. If one or more of these curves is either too great or too small, the head may not be properly balanced over the pelvis. This can lead to back pain, stiffness, and an altered gait or walking pattern.
Kyphosis is secondary to many conditions. It may be congenial due to defects in formation of bones leading to altered structure of bones resulting in kyphosis. It could be secondary to osteoporosis, in elderly osteoporosis will lead to repeated fractures and ultimately results in kyphosis. In India post tuberculosis kyphosis is more common. Tuberculosis causes severe destruction of bones, which results in kyphotic deformity. This is also common in age related degeneration of the disc and some type of cancers with severe destruction of the back. Some bone diseases like scheuermann’s disease can cause smooth round kyphosis.
Mild kyphosis will not cause any problems. But as the kyphosis is progressing, it will lead to body disfigurement with hunch back. As the spine is malaligned, it causes severe back pain. Altered structure of the vertebral column secondary to kyphosis will decrease the space for vital organs like lungs and abdominal organs. This results in decreased exercise tolerance secondary to poor lung function, and decreased appatite(decreased space for abdominal organs). With kyphosis space for spinal cord and nerves may also decreases, resulting in severe leg pains and numbness in legs and loss of balance while walking and finally paralysis.
Kyphosis needs thorough evaluation with x ray, Mri and CT scan. Xray helps in evaluating the flexibility of deformity. CT scan helps in identifying the defects in bones. MRI scan helps in evaluating the compression over the spinal cord and nerves. In case of cancers PET scan and bone scan needed. In case of osteoporosis bone densitometry needed to assess bone strength.
Mild kyphosis will not need any treatment. It needs application of brace and observation with x rays. Moderate and severe kyphosis needs treatment in the form of surgery. Surgery involves fixing the spine with rods and screws and correcting the deformity. Severe kyphosis requires complex and extensive surgical treatments like osteotomy, to correct the deformity, in this spine is fractured intraoperatively and made straight. These are very complex procedures and they are done with intra operative nerve monitoring to avoid complications like paralysis.
Prognosis of kyphosis after correction (expect for cancers), is usually good.