Spine University s Guide to Transient Osteoporosis
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Introduction The word osteoporosis scares many people because they ve heard about brittle bone disease. They may know someone who has had it or seen pictures of women with severely humped backs (called kyphosis) as a result of osteoporosis. However, transient osteoporosis isn t the same thing nor does it end up in the same way. The only thing osteoporosis and transient osteoporosis have in common is that they both affect the bones. Transient osteoporosis (TO) is a condition that affects your bone marrow, the pulpy tissue found inside your body's long bones such as the ribs, breastbone or pelvis. Bone marrow produces red blood cells, white blood cells and platelets. Doctors don't know yet what causes transient osteoporosis. They do know that there's no connection between the disease and whether you've been injured or ill. Therefore, injuring or breaking a hip or knee doesn t cause transient osteoporosis. The disease was first identified in 1959 as bone marrow edema (BME), inflammation of the bone marrow. Transient osteoporosis has been called transient osteonecrosis of the hip, regional migratory osteoporosis, transient bone marrow edema syndrome, and even reflex sympathetic dystrophy. It has been called many different things before researchers settled on transient osteoporosis. Who is affected by transient osteoporosis? Transient osteoporosis most often affects men who are between 40 and 70 years of age and women who are in their last trimester of pregnancy (the final three months). The women, however, are a very small group compared with the men. Transient osteoporosis is rarely seen outside of these two groups of people. What are the symptoms of transient osteoporosis (TO)? Unlike the more well known osteoporosis, which begins very slowly, transient osteoporosis comes on very suddenly and sharply, without warning. The most common area affected is the hip. As a result, the pain from transient osteoporosis can be felt in the groin, buttocks, or thighs. The pain can feel deep and radiate outwards. Although it does most often affect the hip, transient osteoporosis can also affect the other weight-bearing joints: the knees, ankles, and feet. The pain comes as a surprise because it isn t caused by a trauma or injury. In fact, it's usually quite puzzling to the patient. After the sudden onset, the pain usually worsens over a few weeks and can become so severe to the point of being disabling. The pain worsens with movement or on weight-bearing and can ease off a bit when the patient is at rest, although that isn t the case for everyone. Turning is the worst type of movement for aggravates the pain. Along with the pain, your gait, or way of walking, usually changes because you end up trying to protect the sore joint. This causes a limp, which in turn can end up causing muscular pain or even joint pain in other parts of your body as you unconsciously try to compensate for the change in gait. The symptoms usually begin to start easing off within four to nine months, but doctors are unable to tell who will start feeling better earlier than later. Can transient osteoporosis come back? Transient osteoporosis can return to affect the same joints or it can begin in another joint. Again, because doctors don't know what causes it, they can't predict who will get it again. It starts just as suddenly as it did 3
the first time with the same type of pain and progress. How long you've had it the first time doesn't indicate how long it would be a second time, though. How is transient osteoporosis diagnosed? When you see a doctor about the pain caused by transient osteoporosis, your doctor will do a physical examination to look for certain signs and symptoms that may suggest what the problem is. At the same time though, he or she will use this time to rule out problems that can't be causing the pain. If the pain is in the hip, for example, your doctor will check the range of motion, how well you can move the hip as it should be able to move. Although blood tests can't show if you have transient osteoporosis, your doctor will likely order them because they tests will look for other illnesses or disorders that could be causing the pain. These tests are to rule out these other disorders. X-rays are a common test when there's pain that seems to be coming from a joint or bone. Around three to six weeks after the pain has started, doctors should be able to see some changes in the bone and these changes are still often visible for weeks after the pain has gone away. In some cases, the changes have been visible on x-ray for up to two years after the first signs of pain. There is a test called a bone scintigraphy that is sometimes done when people have complaints of joint or bone pain. This test shows changes in the bone metabolism (changes that take place in the cells), unlike x-rays, which show how the bone structure looks at the precise time that the x-ray was taken. A bone scintigraphy can show changes before they're obvious by x-ray. The test is done by watching how a tracer, or dye, moves through the bone structure. Several images are taken over the course of a few hours. Scinitigraphy isn t used for diagnosis only; the test is a good way to follow the progress of the disease and see how well you are healing. Computed tomography or CT scans, are another tool in the doctor's diagnostic toolbox. It's not as effective as scintigraphy because it isn t sensitive enough to small changes, but it may give your doctor a good idea of what is going on. Another test often mentioned in the same breath as a CT scan is magnetic resonance imaging or MRI. While CT scans use radiation (like x-rays) MRIs use magnets to capture images from inside the body. When looking for transient osteoporosis, MRIs can be very good at detecting the presence of bone marrow edema, so it's more effective than a CT scan. What other diseases might the doctor think it is at first? When you first go to see a doctor with any type of medical problem and a list of symptoms, unless he or she can recognize the issue right away, you are a puzzle that needs to be solved. Your doctor will take into account what you say and what your physical examination show to come up with what is called a differential diagnosis. This is a list of illnesses or disorders that could be causing your problem. Once your doctor has this list of possible causes, he or she can start working on eliminating what it can't be and discover what the actual problem is. The list of possible causes for your pain if you have transient osteoporosis include: Regional migratory osteoporosis (RMO). This disease causes pain in many weight-bearing joints. It most often affects middle-aged men, much like transient osteoporosis. And, it begins much the same. However, unlike transient osteoporosis, regional migratory osteoporosis affects mostly the knee, ankle, and foot, rarely the hip. Physically, it's also quite different. If you had regional migratory 4
osteoporosis, your doctor would be able to feel a warm and swollen area around the joint and you would have a decreased range of motion with severe pain. Transient osteoporosis doesn t have that swollen, warm, and tender finding. Osteonecrosis. This is not a common problem but it does occur in about 15,000 people in the United States every year. Although it can be genetic (run in families), there are also some things that may cause it or increase a person's risk for developing it. Like transient osteoporosis and RMO, osteonecrosis affects the weight-bearing joints most often, but with the hip the most common one affected. It also affects mostly middle-aged men but it's also been seen in women over 55 years old. Neoplasia. This is a type of cancer, which can be detected by CT scan, as well as the other bone tests. Inflammatory arthritis. There are a few types of arthritis that could mimic the signs and symptoms of transient osteoporosis. Usually, this can be ruled out fairly early in the diagnosis because arthritis can be seen on x-ray and MRIs. How is transient osteoporosis treated? Transient osteoporosis is what the doctors call a self-limiting disease. This means that the disease will run its course and then go away, much like a cold does. For this reason, there aren't many treatments that can be done for the transient osteoporosis itself, although there are treatments for the pain and disability that can occur while the disease is active. Your doctor may suggest that you use crutches, canes, or some other walking aid for partial-weight bearing. In other words, you want some method to keep you from putting too much weight and stress on your sore joint. Non-weight bearing has drawbacks and isn't often encouraged. When you don't use your leg and avoid putting any weight at all on the joints for a while, this may help the joint that has been damaged. But researchers have found that this may also prolong the course of the disease. You may also be given medications, such as analgesics (pain relievers) and/or nonsteroidal anti-inflammatories (NSAIDs), which are medications that reduce inflammation but without using steroids. In the past, some doctors used corticosteroids to help with treatment, but they weren't found to be very effective. Some patients find some relief of joint pain by doing aquatic (water) exercises. Aquatic exercises are often recommended for people who have joint problems because they take the weight off the joints but allow you to move about freely. Physiotherapy and exercises to maintain strength and flexibility may also be suggested. One of the complications of transient osteoporosis is the reduction in bone strength as the disease progresses. This is a challenge for doctors because if your bones become too week, this could result in other complications, such as fractures or breaks. To prevent this from becoming a problem, your doctor will want you to continue the partial weight bearing (or protective weight bearing) to reduce your risk of injuring the joint. As well, some doctors may try to strengthen the bone, making it less liable to being injured. This means giving you a medication from the bisphosphate family of drugs, which are given for osteoporosis. In one study looking at the treatment of transient osteoporosis, researchers gave patients a medication called pamidronate by intravenous (directly into the vein). They found that this helped somewhat and the results were encouraging. The research using this medication is continuing. 5
In the meanwhile, researchers are emphasizing that the earlier transient osteoporosis is diagnosed, the earlier doctors can be proactive at keeping patients' bones strong by prescribing bone-strengthening treatments, such as calcium, vitamin D, and bisphosphonates. Spine University's Guide to Transient Osteoporosis 6
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