Vertebral compression fractures – Low velocity spinal injuries are common among the elderly. Most vertebral compression fractures occur as a result of osteoporosis. As people get older there is a tendency for the bones to become weaker, particularly in women. The vertebrae of the spine are not exempt from this process and, if it occurs, they are susceptible to fracturing as are osteoporotic bones in other parts of the skeleton. As this is a generalized condition further compression fractures of the vertebrae, as well as fractures of other bones, can occur.
Weakness of the vertebra can arise from other causes apart from osteoporosis due to aging, which include dietary and metabolic factors, as well as the presence of various types of tumours and malformations. For this reason the underlying cause for the fracture must also be determined, and treated if possible. Because the bones are weak it often takes only a very mild (low velocity) injury to bring about a significant fracture.
Vertebral fractures can present in one of two ways in the elderly person:
- The spine slowly becomes shorter as the vertebrae gradually collapse and subside as a result of continual, recurrent ‘micro fractures’. These are tiny fractures of the individual trabeculae making up the vertebra which heal after some displacement. There occurrences typically give rise to a constant, dull ache in the back for which no other significant cause can be demonstrated. For this condition the standard treatments for osteopaenia is usually of benefit.
- If the elderly person trips or sustains a sudden fall this relatively minor event may be sufficient to cause one of the vertebrae to collapse under the sudden strain on the spine. In this instance a compression fracture of the spine will be demonstrated on x-ray. If the displacement is small a period of rest followed by a temporary spinal support and medical treatment of the osteoporosis is usually sufficient. If, however, the pain is severe and prolonged the individual may benefit from stabilisation of the fracture. This can be done in one of two ways.
A method initially devised to manage these particular fractures is termed ‘vertebroplasty’. This technique consists of injecting a ‘cement’ through two small needle tracts into the collapsed vertebra. This substance hardens within the broken bone and supports it, reducing the pain experienced by the individual.
Vertebral fracture reduction with vertebroplasty
A number of enhancements of the vertebroplasty technique have been developed whereby not only is the fractured vertebra stabilised but an attempt is made to restore its height and shape using one of a number of ingenious ways; which include techniques to pressurise the cement, inserting a series of stacking plates, an expanding balloons. These methods attempt to correct the abnormal angulation of the spine which has occurred because of the fracture, which is called a ‘kyphus’. By restoring the alignment of the spine its normal biomechanics are restored which reduces (but does not eliminate) the chance of further such fractures from occurring. These techniques can also be a useful way of treating some fractures of the spine due to malignant disease.
There is, as is usual with most surgical procedures, controversy as to how soon after the injury they should be used, if at all. Not all types of vertebral fracture are suitable for these techniques. There are physicians who advocate that, as the fracture often heals by itself and surgery has its own risks, it should initially be treated using conservative measures and that these surgical procedures should only be performed if the pain from the fractured vertebra continues. Unfortunately if left for more than a week or so the fracture has begun to heal and it is sometimes not possible to bring about any correction of the deformity.
In those people in whom the pain from the untreated fractured vertebra continues it is often severe, protracted and disabling. It is not possible to determine in whom the pain will continue but when it does it generally needs some form of surgical intervention to relieve it. There is thus a reasonable argument for the early stabilisation of these fractures. Stabilisation generally brings about a degree reduction of pain immediately, even if delayed, but late surgery does not usually correct the ‘kyphotic’ deformity of the spine.
Pelvic insufficiency fractures – relatively common injuries mainly affecting elderly individuals. They usually occur in association with weakness of the bone of the pelvis: the result of aging, excessive steroid intake, hyperparathyroidism and various tumors. The fractures themselves are usually brought about by a fall which, seemingly, may initially appear to have been relatively minor. Nevertheless, the pain from these injuries can become quite severe. It is aggravated by activity, which affects the individual’s ability to walk and sleep. Unfortunately these injuries are frequently overlooked as the cause of the person’s discomfort which can to inadequate treatment and, overall, they can be responsible for quite severe morbidity of the injured person.
Two areas of the pelvis are commonly affected, the sacrum and the pubic rami. Sacral insufficiency fractures typically cause severe pain in the lower back, which may also radiate into the buttocks, both hips and the groin. The pain from fractures of the pubic rami is typically felt in the groin or hip. In some individuals it may be found that there are fractures in both areas of the pelvis.
The fractures in both areas can be associated with significant associated injuries. Some fractures of the pubic rami may be associated with injuries to the bladder, urethra and vagina, and can cause impotence in males. Fractures of the sacrum can be associated with injuries to the nerves, causing sacral radiculopathy and the cauda equina syndrome.
Diagnosing this fracture can be difficult as it typically does not show up very well on routine radiographs and usually requires multimodality imaging. These should include CAT or MRI scans. Technetium bone scanning is highly sensitive and can be a useful adjunct, particularly with bilateral sacral injuries when it shows a typical H-sign across the sacrum.
In the past the treatment of pelvic insufficiency fractures has been conservative, with bed-rest and analgesics its mainstay. More recently surgery has gained increasing prominence, particularly if the fractures have been complicated by visceral or neurological injury. Ileo-sacral screws are a classical method of treating many sacral fractures while plates and screws are a standard form of surgical treatment for pubic rami fractures. In addition to surgical implants, the use of polymethylmethracrylate (sacroplasty) is also a relatively recent mode of treatment for sacral insufficiency fractures. As with vertebral compression fractures of the spine, treatment of the underlying bone weakness and its cause is also of major importance.