Spondylolysis, Spondylolisthesis, Rheumatoid Arthritis, Ankylosing Spondylitis and Osteoporosis

A defect in the pars interarticularis region reduces the ability of the posterior elements to stabilize the spine, and spondylolysis may progress to spondylolisthesis. (35,36) Spondylolisthesis is the slipping forward of one vertebra on another. (34) While spondylolysis can lead to spondylolisthesis, there are other causes, including dysplastic L5-S1 facet joints, degenerative changes in the facet joints, pathologic lesions, and trauma. (37)

Inflammatory Conditions
The same inflammatory diseases that affect the other areas of the musculoskeletal system can also affect the spine. Rheumatoid arthritis can cause erosion of the synovial joints of the upper cervical spine, leading to instability, pannus formation, and even cranial settling, (upward migration of the C2 body and dens toward the foramen magnum). Malalignment and instability result from destruction of bone and supporting ligaments by synovial proliferation. These changes can potentially compromise the neural structures at this level, with devastating consequences. (38,39) Ankylosing Spondylitis is an inflammatory condition characterized by ossification of the sacroiliac joints and the spinal discs and ligaments. Eventually, the spine becomes fused across the disc spaces, resulting in the characteristic radiographic finding of 'bamboo spine' (Figure 7).

Figure 7.
Lateral radiograph of a patient with Ankylosing Spondylitis. Notice the ‘bamboo spine’ appearance.

This resulting loss of mobility of the spine places patients at risk for fracture with neurologic injury. (40,41) In a retrospective, descriptive study exploring the neurologic consequences of spinal fracture in patients with ankylosing spondylitis, minor trauma such as ground-level falls was sufficient in most (8 of 11) cases to cause spinal fracture. Most fractures occurred through the ossified disc spaces, and spinal instability was demonstrated in 10 of 11 patients. Half of the fractures were accompanied by neurologic deficit. (42)

Osteoporosis
Osteoporosis is a disease of the bone characterized by deterioration in bone structure and lowered bone mass, leading to increased fragility of bone tissue and susceptibility to fractures, particularly in the wrist, hip, and spine. In the United States today, an estimated 19 million people have osteoporosis, and an additional 34 million have low bone mass that places them at risk for developing the disease. (43) Eighty percent of those affected by osteoporosis are women. It is predicted that one in two women and one in eight men aged 50 and over will have an osteoporosis-related fracture in their lifetime. (43) More than 1.5 million fractures each year are attributable to osteoporosis, and nearly half of those fractures are vertebral. (43) Risk factors include female sex, small frame, advanced age, postmenopausal status, family history of osteoporosis, use of certain medications, a diet low in calcium, and many others.

In a phenomenological study undertaken to document the experience of postmenopausal vertebral fracture in elderly women, several themes emerged. (44) The dominance of pain and the fear of future pain was a common theme, regardless of the age of the fracture. The deforming aspects of the disease were a threat to the women's self-image, feelings of vulnerability were expressed, and relationships with family and friends were affected by difficulties related to pain management.

Both pharmacologic and non-pharmacologic treatments are available for the treatment of pain associated with osteoporotic vertebral fracture. Non-steroidal anti-inflammatory medications, (especially the cox-2 inhibitors), topical treatments, injections, and careful use of narcotics (because of the constipating side effects) may be used. (45) Physical therapy, braces, and vertebroplasty or kyphoplasty are among the non-pharmacologic treatment choices.