Margaret Hawkyard knew something was wrong when she drove over a speed bump and felt her back seize up, suddenly and painfully. A few months later, she reached up to open a garage door and felt the same unpleasant jolt. Soon after, it got so bad that she couldn’t get into bed without help. “My GP kept saying it was muscular and giving me painkillers. I’m not soft, but I was so desperate that I paid to see a specialist By then, I couldn’t get on the couch to be examined and he had to give me morphine to get home.” Hawkyard had been treated for breast cancer in the past. “After seeing the scan, the doctor said that the good news was that the cancer hadn’t come back, but the bad news was that I had five or six vertebral fractures.” It took three months of physiotherapy before she started to recover.“But it took me much longer to get my confidence back and get over my fear that it could happen again.”
Hawkyard’s back had broken because of osteoporosis, a condition that makes bones weak and fragile. It rarely causes symptoms until a minor fall or sudden impact makes a bone break. The wrist, hips and vertebrae are the most vulnerable because they take most of the impact, but any bone can break if it is weak – even a violent sneeze can fracture an osteoporotic rib or vertebra. Professor Justin Cobb, chair of orthopaedics at Imperial College London, says: “Osteoporotic bone is like a honeycomb that is gradually becoming more fragile and can be squashed by too great a force; it’s fine while it’s sitting on the shelf, but if you drop it, it’s going to break.”
Once bones become weak, treatment options are limited. The most commonly prescribed treatment for osteoporosis is a group of drugs called bisphosphonates. And they have come under scrutiny recently as new research – admittedly on a tiny sample of cases – has raised some questions about their use.
Imperial College London researcher Dr Richard Abel explains that a colleague noticed when he was carrying out hip replacements on patients taking bisphosphonates that the bone was more “crumbly” than expected. Abel wanted to test the idea that the treatment might actually be weakening bones. He used new technology to test bone strength in tissue samples from osteoporotic hips that had fractured. Some samples came from people who were on bisphosphonates, some weren’t, and others came from cadavers of the same age, without osteoporosis. Non-osteoporotic bone was stronger than osteoporotic bone, but bisphosphonate-treated bone was weaker than osteoporotic bone from people who hadn’t been treated. Abel says that the loss of strength, if confirmed, may be due to the accumulation of lots of micro-fractures.
Cobb explains that although atypical fractures are rare, they can be devastating. “One woman said she felt that her femur was going to break in the middle, just like her other one had. She pushed herself up in bed one morning and it just snapped, like a cracked mug suddenly breaking. Normal bone just doesn’t do that.” Cobb says we need to know more about the pros and cons of bisphosphonates. The drugs are often prescribed because a bone density scan shows signs of osteoporosis. “But we’re treating the scan, not the person,” he says. You can have a normal scan and still fracture easily because you fall a lot, explains Abel. “We need to be able to measure bone health with a combination of bone strength and risk of falls.” Both are also concerned that bisphosphonates may also be given for longer than necessary; at present they are usually prescribed for five years but as the drugs stay in the body for several years, it may be possible to treat for shorter periods.
But other experts disagree; bisphosphonates are the best treatment for osteoporosis that we have at the moment, and the benefits outweigh the risks, says the National Osteoporosis Society. Professor David Reid, of the University of Aberdeen, is worried that adverse publicity will mean that people stop taking them. He says Abel’s study is well designed and uses clever technology, but is too small to draw any meaningful conclusions. “Micro-fractures, or atypical fractures, are nothing new,” he says. “And for every atypical fracture that may be due to bisphosphonates, you prevent 130 fractures. If people overreact to this preliminary study by stopping treatment, it will cause many avoidable fractures. This is a huge scare story that has had a big impact and is bad for patient care.”
New treatments on the horizon may offer a better option; Romosozumab stimulates new bone formation and is in clinical trials. And drugs such as teriparatide, denosumab and strontium ranelate are available for specialist use when standard treatment has failed. Women such as Margaret Hawkyard can be offered vertebroplasty – essentially cement injected into the vertebra – to stabilise vertebral fractures and reduce pain. But the truth is that none of the drugs are free of potential side-effects; it is clearly preferable not to develop osteoporosis in the first place.
Professor Juliet Compston, of the University of Cambridge, says it’s important to start early. “You have peak bone mass at 20 to 30 years old and then, after the age of 40, everyone starts to lose bone. If you live to 90, you’ll have thinnish bones, whatever you do.” For strong bones you need good genes, she says, plus plenty of weight-bearing exercise, to avoid smoking or excess alcohol, stay in the normal weight range and get adequate vitamin D from sunlight and calcium from the diet (around 750mg a day for adults should be enough). It’s not clear how much calcium is enough in childhood though the government has issued guidance. Calcium supplements are no better than calcium from the diet, and too much calcium can cause constipation, kidney stones and possibly heart disease. Vitamin D supplements of 400-800iu a day are a good idea for frail and housebound people, but people who take high-dose vitamin D in short bursts should be warned that there is some evidence that intermittent, high doses may increase fracture risk.
Hormone replacement therapy (HRT) for women in their 50s, who are at high risk of fractures, can reduce the risk, but treatment shouldn’t usually exceed five to 10 years. Compston is clear on bisphosphonates, however: if you have a high risk of fracture, take them for five years and then reassess; the benefits outweigh the risks.
Cobb says the most important defence is to keep active. “Muscles and bones work together and age together. You don’t need to be running marathons, just keep doing gentle weight-bearing exercise that keeps your balance strong too. Drugs are not going to be the answer; if I could prescribe ballroom dancing for everyone, I would.”
National Osteoporosis Society helpline: 0808 800 0035.
