A short patient-oriented information leaflet about osteoporosis of the spine and the surgical options for treatment

The following information was put together to help in the decision-making process. The graphs show the answers of the members of EuroSpine, the Spine Society of Europe, considered to be the European experts in the field of treatment of spine pathology. This information should help you to learn and understand what most of the experts in the field would do in each specific situation. The information reflects a “common sense” approach to treatment of the members of EuroSpine, yet does not replace a careful evaluation of your individual situation. Therefore, if you find a significant difference between the answers below and you doctor’s opinion, ask your doctor what made him/her reach this decision.

Each specific situation has to be evaluated on an individual basis. EuroSpine and its members cannot be held responsible for any misunderstandings (or misdiagnosis) based on the information provided here, which in no way attempts to replace a targeted evaluation.

Osteoporosis is a disease of the bone that leads to an increased risk of fracture. In osteoporosis the bone mineral density (BMD) is reduced, the bone microarchitecture is disrupted, and the amount and variety of non-collagenous proteins in the bone is altered. Basically, there is a thinning of the bone structure which affects the bone’s strength (Fig. OP1 ). It may affect every bone in the body. Some bones, such as the wrist bone, the femur and the vertebrae, however, are more prone to develop symptoms or to fracture due to their anatomical structure and mechanical exposure.

The decrease in mechanical strength may cause vertebral fractures to simply happen without trauma or injury. It is estimated that up to 50% of females (30% for males) experience at least one osteoporotic vertebral fracture during their life. Vertebral fractures due to osteoporosis can give rise to a sudden onset of pain. The patient feels a sudden sharp pain (often associated with a “crack” in the back). It is usually worse during activities and reduced at rest. An X-ray or magnetic resonance scan (MRI) will confirm/reveal the fractured vertebra.

Often this gets better within 3-12 weeks as the fracture heals, and there are no ill effects. Sometimes the fracture is slow to heal and persistent pain and reduced physical activity occurs with secondary effects such as negative self esteem, mood and body image.

Sometimes , particularly with multiple fractures, this may result in deformities and loss of balance of the spine. (Fig. OP2 ).

This is why early treatment to strengthen the bone is recommended. Deformities of the spine create abnormal loads and further increase the risk of additional fractures and increasing deformity. (Fig. OP3,4). Surgery may be indicated to stop this process and slow the progression of any deformity.

Due to the self-healing capacity of the bony fractures in the spine, “silent” fractures are not uncommon: after a period of back pain, the patient improves with time and forgets about the episode. X rays, performed for other reasons at a later date may reveal the fracture site, now without symptoms.

Not all vertebral fractures in older people are due to osteoporosis. Osteoporosis therefore has to be proven prior to starting treatment.

Clinically, a history of low energy fractures of the spine, wrist or hip would suggest osteoporosis. In the typical situation, the patient will report an audible crack in his spine associated with a sudden onset of sharp pain whilst lifting an object or during an unusual movement of the body. Blood tests are often normal but are performed to exclude other conditions that can weaken bone.

An ordinary X-ray is not reliable enough to diagnose osteoporosis. The type and aspect of the fractured vertebrae might, however, raise the suspicion of an osteoporotic origin.

The most reliable test for osteoporosis is the DEXA (dual-energy X-ray absorptiometry). With this examination it is not only possible to confirm osteoporosis but also to quantify the severity (normal-osteopenia-osteoporosis-severe osteoporosis). These results provide information about the severity of the osteoporosis and may be helpful in choosing the appropriate therapy. However, DEXA is not always necessary and a low energy fracture itself is a diagnosis of severe osteoporosis.

In doubtful situations, a biopsy might be helpful to confirm diagnosis.

Non-operative treatment

Non-operative treatment aims at preventing the progression of osteoporosis by influencing the metabolism of bone. A healthy diet and healthy lifestyle with exercise are important steps in treatment. Prevention of falls, “protective” devices such as walking sticks or crutches may be helpful.

There are specific medications that inhibit or slow the further loss of bone mass (bisphosphonates, hormones, and others) and encourage new formation of bone (parathormone). In general, the incorporation of calcium and improvement of the bone quality takes months and years. This treatment should therefore be continued for a long period and patients should be followed on a regular basis. Calcium and Vitamin D are among the important adjuncts in the medical treatment of osteoporosis.

The treatment (and prevention) of osteoporosis is general and treats the whole patient. The treatment of an osteoporotic vertebral fracture may include treatment of the fracture itself.
It is estimated that only about 10% of all osteoporotic spinal fractures need interventional treatment. Most of the fractures either heal spontaneously (often even undetected by the patient) or with temporary pain medication.
In situations with moderate, primarily posture-related pain, an external support such as a corset may be helpful to reduce symptoms. However, it cannot be expected that an external support will be strong enough to correct deformities after fractures have occurred.

Surgical treatment

The main goals of surgical treatment can be summarized in the following points:

1. Pain relief
2. Stabilisation of the fractured vertebra
3. Reduction of deformity
4. Decompression may be necessary if there is pressure on the spinal cord
5. Alignment of the spine

Each patient may have different needs or problems and it may not be possible or safe to try and achieve all the goals of treatment. In dealing with increased curvature or reduction of deformity, consideration may sometimes be given to extensive surgical procedures such as osteotomies and long instrumentation.

This technique reinforces the bony structure by injecting bone cement into the vertebral body. Two different techniques are currently in use. The vertebroplasty and the kyphoplasty.

In both techniques a percutaneous procedure is used, where bone cement or similar material is injected directly into the vertebral body (Fig OP5) through the pedicle of the fractured vertebra.

In vertebroplasty, the cement is injected directly into the spongious part while in kyphoplasty the space for the cement is first prepared with a balloon. This balloon is inflated in the deformed vertebra, thus having the potential to lift the depressed fractured endplate and to restore the original height of the vertebral body. (Fig OP 6,7,8). Such a correction is only anticipated in fresh fractures while the bony parties are still movable.

What to expect from intravertebral stabilisation?

The intervention is usually performed through the skin with small incisions at the level of the fractured vertebra. An X-ray machine is used to ensure correct placement of the needles that are used. The surgical trauma remains small.

Almost immediate pain relief or significant pain reduction is observed in the majority of cases. Kyphoplasty and vertebroplasty can both produce good results in terms of improved pain but this result may depend on factors such as time elapsed since fracture, anatomy of the fracture and localisation of fractured vertebra. A scientifically sound study shows that at one year kyphoplasty has significant benefits over non-operative care in terms of pain relief, physical function, reduction of analgesic intake and overall quality of life. There is no such study for vertebroplasty. In addition, kyphoplasty may potentially prevent the development of increasing kyphosis with its associated complications.

Risks of intravertebral stabilisation

Even if this is a minor surgical procedure, it carries some risks of complications. The indication has, therefore, to be carefully balanced against the risks.

The general complications in relation to anaesthesia are no different from major surgical procedures if performed under general anaesthesia. They are also dependent on the patient’s general health.

Insertion of the needle is performed under X-ray or CT control to make it as safe as possible. Nevertheless, there is a small risk of misplacing the needle. The consequence might be anything from minor sensory disturbances to complete muscle paralysis below the corresponding level.

The injected cement may escape the anatomical borders of the fractured vertebrae. The consequence of this depends on the localisation and the anatomical structure of cement leakage. If the cement leaks into the psoas muscle and the surrounding soft tissue, some pain may be produced but this usually subsides spontaneously. Leakage of cement into the spinal canal may induce damage to the spinal cord/nerves depending on the volume. If the cement leaks into a major blood vessel, lung embolism and subsequent respiratory problems can occur. Kyphoplasty tends to have less serious cement leakages but the clinical results of both procedures are similar.

What happens if you do not have intravertebral stabilisation?

The natural history of any thoracic or lumbar spine fracture is good, with early improvement for many. The worst pain arises early on, improving quite quickly by the time 2-3 months have passed. However, there is a certain percentage where the pain persists.., There is a certain risk of further fractures, which will increase the deformity, if there is a severe kyphosis either produced by the fracture(s) or pre-existing in the spine. In rare cases, this deformity may lead to significant impairment.

Segmental stabilisation has to be performed if severe deformity is present or malunited vertebral fractures exist. The number of segments to be included depends on the individual pathology and type of deformity. The technique of instrumentation and correction follows the general principles of spinal surgery. The osteoporotic spine presents the challenging difficulty of weak bone structures. Any instrumentation of the spine relies on a solid bone-implant interface and a good grip of metal fixation. This strength is compromised in osteoporotic bone and requires some special techniques.

To overcome this difficulty, the extent of fusion has to be increased, taking into account that multiple anchoring points may compensate the weakness of each single point. Balancing the spine becomes more important in order to avoid stress peaks at the end of instrumentation and the risk of failures (Fig OP 9, 10). The consequence is usually extensive length of instrumentation (Fig OP11). In addition, rigid deformities require osteotomies of the spine in order to perform the fixation in an alignment which is balanced over-all (Fig OP 12). Finally, the stability of each screw can be increased by using special screws in conjunction with cement. (Fig OP13)

Legend to figure OP 12

In spite of these precautions, loosening of implants is quite a common occurrence. Fixation down to the sacral bone of the pelvis is particularly difficult and problematic. These are major surgeries and carry significantly greater risks in terms of severity and number of complications including death. By comparison, trying to prevent the deformity by means of a procedure such as kyphoplasty carries a relatively small risk of serious complications but might only be advised in specific situations.

Risks and complications

These corrective interventions are major surgical procedures. They require the patient to be in good general health. The length of surgery (usually more than 6 to 8 hours), medication during anaesthesia and extensive haemorrhaging may be simply too much for some older and frail patients.

The placement of instrumentation in the spine carries some risk of injury to the nerves and spinal cord. The risk is one of paralysis, which is loss of use of the legs and loss of sensation in the skin. Control of the bowel and bladder may be affected. The bigger the operation, the greater the risk of a serious complication. The operation may be safer if there is intra-operative monitoring of the spinal cord. This allows on-line control of the functional status of the spinal cord and the nerve roots involved and can therefore reduce the risk of serious neurological damage.

The reduced mechanical properties of the bone may produce secondary loosening of the implants and consecutive loss of correction. If significant, a re-intervention might be necessary to restore alignment and reduce pain.

A moderately deformed spine in itself is not a life-threatening situation but the quality of life might be considerably reduced by pain and physical and social disadvantages so in rare cases this type of intervention may be justified nevertheless.

What happens if you don’t operate?

Osteoporotic fractures often heal and pain will often subside. If deformities are present, the risk of progression increases with the degree of curvature and bone quality. In rare situations with advanced stages, the deformity and/or encroachment of the spinal canal may produce neural damage as described above.

Fuente: Eurospin