Rory Hafford combs the studies for the best management approach to the increasingly common complaint of vertebral fractures
Osteoporosis has long been considered as the ‘silent disease’. But when the fractures start to kick in, the fall-out is anything but silent. Indeed, as our popul-ation ages, we are facing into the prospect of trying to deal with an avalanche of osteoporotic-related consequences, chief among which are fractures.
As the bones weaken, so too does the natural resolve of the hip and the wrist and other small-joint sites. However, the daddy of all fractures is the vertebral fracture.
Vertebral fractures are the most common complication of osteoporosis. Defined as ‘a 15 per cent to 20 per cent or more decrease in vertebral body height’, vertebral fractures are exercising both the ingenuity and resources of doctors.
The spine itself really is a miracle of evolution. Comprised of 24 separate vertebrae, plus the sacrum and the coccyx, the backbone is the physical representation of strength and solidity. The topmost vertebra goes by the name ‘atlas’, because it supports the globe of the head, as the Titan of Greek mythology supported the earth.
The atlas – along with the second cervical vertebra, the axis – forms the joint connecting the skull and spine. The atlas and axis are specialised to allow a greater range of motion than normal vertebrae. They are responsible for the nodding and rotation movements of the head.
Many people with vertebral fractures do not seek medical intervention. The clinically silent nature of the anomaly throws a veil over the problem until it turns up via something innocuous, like a chest x-ray.
There are, however, a number of ‘red flags’: kyphosis, loss of height or pain caused by the crowding of internal organs.
According to one study (Nevitt et al), “The incidence of radiographically demonstrated vertebral deformities was associated with increased frequency of back pain and limited activity, as well as increased duration of bed rest due to back pain.”
The pain itself can be caused by changes in the alignment of the spine, spasm of para-spinal muscles and an inordinate stretch on ligaments. As an initial dampener, analgesic and muscle-relaxant agents can be of some use.
Trauma
Generally, some trauma occurs with each compression fracture. According to Old and Calvert, in cases of severe osteoporosis, the cause of the trauma may be simple, such as stepping out of a bathtub, vigorous sneezing or lifting a trivial object. Indeed, the trauma could result from the load caused by a simple muscle contraction.
Simply put, the applied force usually causes the anterior part of the vertebral body to crush, forming an anterior wedge fracture. The middle column remains intact and may act as a hinge. This results in loss of anterior height of the vertebra while the posterior height remains unchanged. As the collapsed anterior vertebrae fuse together, the spine bends forward, causing a kyphotic deformity.
According to the recent article, ‘Vertebral Compression Fractures in the Elderly’, published in the American Family Physician Journal, about two-thirds of vertebral fractures go undiagnosed, primarily because people regard them as symptoms of arthritis or as a normal part of ageing. Physical examination is key. Normally, it will reveal tenderness directly over the area of acute fracture and an increased kyphosis can also be present.
In cases of uncomplicated compression fractures, the study shows that “straight leg raises will be negative and neurologic examination will be normal”. Ileus, or decreased bowel sounds, may be present.
Malignancy, not osteoporosis, should be considered as a possible cause in patients younger than 55 who present with a compression fracture without trauma or only minimal trauma.
An MRI can be a useful diagnostic tool in this case, as it allows for the differentiation of oedema caused by a benign fracture from that of tumour infiltration, according to Old and Calvert.
According to Reiter (2009), a neurologic examination should be performed as part of the expanded primary survey or secondary survey. It should include the cranial nerves, motor and sensory components, co-ordination and reflexes.
The pelvic and perineal areas and the extremities should also be examined. A rectal examin-ation is indicated, especially if the patient has weakness in the extremities.
“An injury to the thoracic or lumbosacral cord would likely result in neural deficits at the trunk, genital area and lower extremities,” said Dr Reiter.
Fractures secondary to infection also need careful consideration. For example, Pott’s disease results from the haematogenous spread of microbacteria to the spine. Other bacteria, according to the study by Reiter, can be spread to the spine and cause osteomyelitis.
Kyphotic deformity
“As bacteria proliferate, vertebral damage occurs and primarily affects the vertebral bodies,” said Dr Reiter. “As in the case of pathologic fractures, associated fractures and an increase in kyphotic deformity may be present. Treatment includes antibiotics. The presence of a neurologic deficit may prompt instrumentation and stabilisation of the spine.”
Preventive measures and follow-on advice can include: an appropriate exercise programme post-fracture, a well-balanced diet, calcium and vitamin D supplements, an end to smoking, and medications to treat osteoporosis, such as bisphosphonates. According to Old and Calvert, “Age should never preclude treatment.”
Treatments options
What is coming down the line with regard to treatment options? Vertebroplasty and kyphoplasty are two relatively new procedures indicated in the more serious cases. There are similarities in both approaches, with percutaneous injection of bone cement into one or more fractured vertebrae being the first step.
Kyphoplasty works almost like a scaffold, with the injection re-inflating the collapsed vertebra and attempting to give it the solidity that it has lost. Currently, however, kyphoplasty only comes into play if the patient is suffering from chronic pain and their pain cannot be controlled by other measures.
The main difference between kyphoplasty and vertebroplasty is the insertion of a balloon into the fracture. The purpose behind this is to create a space for the insertion of the bone cement and to help restore vertebral height.
The extra space created also allows for the use of a thicker cement, which in turn reduces the risk of leakage.
The pain-relief figures are good with these two approaches, with 60-100 per cent relief being reported. There is a flip-side to this particular approach: studies are ongoing and in the early stage, so the evidence base is not as strong as it could be. Also, there is the risk of spinal-cord compression.
Bisphosphonates
When it comes to the pharmacological approach, a number of developments are now in place. Take the bisphosphonates, for instance. Basically speaking, bisphosphonates work by preventing the loss of bone mass.
A study by Dr Elizabeth Shane, published in the New England Journal of Medicine, found that by inhibiting the function of osteoclasts, bisphosphonates reduce the risk of osteoporotic fracture and do so while boasting an excellent safety profile.
Of the bisphosphonate that is resorbed or infused, about 50 per cent is excreted unchanged by the kidney. What is left over has a very high affinity for bone tissue and is rapidly absorbed onto the bone surface. Bisphosphonates have a number of indications: for the treatment of osteoporosis, Paget’s disease, bone metastases and multiple myeloma.
Strontium ranelate is another drug that is having a positive effect on osteoporosis. Its mode of action is revolutionary: it not only slows down the work of the osteoclasts, but it also stimulates osteoblasts to lay down new bone.
Servier, the drug’s manufacturer, has just published test results from a five-year study of more than 5,000 women with osteoporosis. It found a 16 per cent risk reduction in non-vertebral fractures, an 8.2 per cent increase in bone mineral density at the femoral neck and a reduction in vertebral fracture by 39 per cent.
About admin
Loading ...
