Osteoporotic fracture in the spine usually refers to a fracture of the vertebral body. Now, this is a lumbar spine, lower aspect of the whole spine. Osteoporotic fracture can occur anywhere in the spine, but just to illustrate, I'll use this. So this is a vertebral body. It is composed of bone that is meant to withstand forces on it. Osteoporosis in itself is decrease in density of the bone. When you decrease the density of a structure that is meant to withhold forces, it is no longer as strong as it used to be. Now, sometimes it becomes so weak that it can spontaneously collapse and when it spontaneously collapses, it can do so in a variety of different ways. Most commonly, it causes a wedge fracture in which case, it usually wedges from here to this form. Now, when it wedges, and that can happen either spontaneously or because it's not as strong as it used to be, it can happen with just minimal trauma. And that minimal trauma could be missing a step while stepping off a sidewalk. That tends to cause pain. When I say 'tends to,' I say that because it doesn't have to. Some people find they have osteoporotic fractures that they never knew about and what that does is it actually changes the curvature of the spine and that's how we think about getting older and losing height - that's the most dramatic height loss that can happen to a person.
Now, osteoporotic fracture that causes pain traditionally was thought to cause pain through movement - micro movement to be precise. The fracture site itself is no longer stable. When it's not stable, it is free to move, so when it moves, it tends to cause pain. Traditionally, these fractures tend to heal themselves and pain tends to be short lived. When I say 'short lived,' it's not a matter of days - we are still talking a matter of weeks, so that pain can vary from an ache and considerable interruption to the daily activities to severe pain that really stops a person in their tracks.
Sometimes when the fracture heals, the pain persists. So, in terms of treatment, we are really treating mainly the pain that arises from this and if we can the mechanical changes and the forces that come from the loss of height. In talking about the mechanics of the spine, it's important to remember that the spine is essentially a stack of vertebrae. These vertebrae are stacked and there are three points of contact. In the front there is the disc that separates the vertebrae. In the back there are two joints; the small facet joints or hinge-like joints. So, essentially, what we end up with is a tripod. That tripod distributes the forces equally or physiologically appropriately to different aspects of that tripod. When one of the legs is no longer there or is not there in the same way as it was mechanically previous to the injury, that puts more force through the other legs that are still there, so that changes the mechanism of the whole level that segment that is comprised by the vertebrae that come into contact. The reason I mentioned that is because in new research, we've seen a change in paradigm, whereas before the mainstay of treatment was either: if the pain was controlled or can be controlled by pain medications, then it was relative rest and controlling of the pain or we would do a procedure by which we would insert a catheter into the actual vertebral body that is now compressed, use a balloon to expand it back to its original height and then fill that void or that newly developed space with cement and that would stabilize the segment and reduce the pain and also restore the mechanical integrity of that level. Now the paradigm shift is not to the point where that's no longer applicable - it certainly is applicable when it is appropriate - but what we understand now is that that pain doesn't necessarily come from that fracture only and that's the reason that some people tend to have pain long after the fracture has healed. It is due to those mechanical changes that those facet joints are now taking up more and more strain and it is a well-defined in literature through biomechanical models, the fact that that can be a source of the pain. We also know that through diagnostic tests, by blocking these facet joints, we can alleviate pain that seems to come from the fracture, and that makes sense once we look at that biomechanical model.
So, with osteoporosis, with osteoporotic fractures, it is very important to treat the osteoporotic fracture itself if it is applicable. It is important to remember that that is not the only potential source of the pain. However, it is also very important not to develop tunnel vision and in treating that, it is also important to treat the underlying source of this fracture, which is osteoporosis. So, it is important to look at what causes osteoporosis and try to reverse that through the means that are available to us in order to prevent further osteoporotic fractures.
In This Article:
- Osteoporotic Fractures of the Spine Video