Kyphosis and the Loss of Sagittal Balance with Aging

Causes

There is a normal curvature to the spine from the head down to the pelvis, which keeps the upright human in proper alignment and balance. When viewed from the side, the cervical spine (neck) bows forward (lordosis), the thoracic spine with its ribs bows in the opposite direction to the rear (kyphosis), and then the lower lumbar region bows forward again. (lordosis). The integrity of the spinal column and its proper balance is made up of contributions from both the vertebral bodies as well as the intervening discs.

With aging, two concurrent and often related processes take place. First, the flexible, shock-absorbing inter-vertebral discs, gradually lose some of their water content, and begin to shrink down in size, and in some cases late in life, collapse completely. As these discs contribute to the spinal column's curvature, their collapse can lead to a loss of that curvature and a posture that tends to lean forward. An older, more arthritic spine that is stiffer cannot adequately compensate above or below to maintain balance. At the same time, in the later decades of life, especially with the loss of hormonal protection (menopause), osteoporosis can soften the vertebral bodies, and even minor trauma can lead to compression fractures. These may be completely without symptoms in certain individuals; however they typically heal in a collapsed or angulated fashion, further pitching the spine out of balance. This is especially common in the mid or thoracic part of the spine, wherein the increase in curvature here is called kyphosis.

Treatment Options

The treatment is one principally of prevention. Regular aerobic and anaerobic exercise and the avoidance of activities such as smoking which promote disc degeneration, aim to maintain flexibility and postural control, while exercise, regular bone density examinations and if necessary, bone strengthening medication are the mainstays at preventing and/or treating the fractures associated with osteoporosis.