Adult Fractures (Part 4 of 5) - Myles Clough, MD

Dr. Sechrest: I think to be complete with this discussion, what we also need to do is help patients understand the difference between the ways that we physically fix fractures. We talked about the cast. We talked about traction. Now let’s focus on when do I use wires, k-wires, pins? You know people hear all these terms. But there’s a whole gamut of devices that we use including plates, screws, with a plate or without, pins that we somehow just shoot through the bone. We use rods which go in the middle or the marrow cavity, and we use external fixators.

Dr. Clough: Yes.

Dr. Sechrest: Different ways of all accomplishing the same thing, really trying to align the bone and hold that bone in alignment until it heals. I mean that’s what we’re really trying to do with all of these techniques. Define for patients a little bit how you, as an orthopaedic surgeon, may make the decision as to whether this patient would be right for a rod versus a plate and screws versus just screws or versus an external fixators, something that’s outside the skin that goes through the skin with pins that holds with an erector set looking thing on the outside. So discuss that a bit.

Dr. Clough: I think the first thing to say about it is it’s quite unique to the surgeon involved, and if you’re a surgeon who’s trained in Russia you would be an absolute expert at using external fixators because they developed a lot of techniques there and they’re not so expert at using other forms of internal fixation. Whereas if you’re in North America, you use external fixation far less often. But it doesn’t mean that the Russians are right and we’re wrong or the other way around. It means that the surgeon has very sensibly used the technique that he’s most familiar with and has got the greatest confidence in. Now as far as when do you use various different devices, I think one can kind of separate off, for me at any rate, the external fixator. An external fixator one most often uses in our area as a way of aligning the bone without disturbing the fracture and also without compromising the care of a wound. So we typically see this in major open fractures where there’s a huge terrible wound in the middle of the leg and you can put the pins in at either end of the bone, keep the bone in alignment, and then treat the soft tissue. Treat the wound, get the wound to heal, and then very often in our area, having converted it from an open fracture to a closed fracture, you then go and do an operative measure that’s internal fixation and take the external fixation off. Although that’s not totally the case everywhere in North America, I think that external fixation is used most often for wound problems and less often as the most kind of the first line of treatment for a fracture. Would you agree with that?

Dr. Sechrest: Yes, I would.

Dr. Clough: Well, it doesn’t mean that if your doctor has chosen an external fixator it’s because he or she feels that you have a terrible wound. You may not. It may be that their training, their experience, or something that they’ve recently learned, has suggested that an external fixation device was the best way of doing it, and honestly, I think there may well be situations in which we use an external fixation much more often in the future. So what about simple internal fixation, and by that I mean pins or pins and screws. A pin is little fine wire, not much bigger than a needle and the hallmark of a fracture that’s using a pin is it’s small. You use a pin to immobilize a fragment that’s relatively small where you think that if you put a bigger object, a screw, or a rod, or a plate or something, you might not have room. Because that piece of bone, although critical and although needing to be put back in place, is perhaps too small to accept a major object. So I’ve seen it a lot in wrists where a wrist fracture that’s quite splintered may have a number of tiny small pieces and you may want to get them all back into a good position. Wrist fractures are often treated by open reduction with a plate nowadays but, in some situations and in some types of fracture, you can get the piece back held with a simple pin. So I think you would use that for a small fragment and you’d probably use a screw for a simple situation also. I would say the commonest situation where you use screws alone would be in the ankle, a common type of ankle fracture is where the inner bump on the inside of your ankle is pulled off, the fracture is straight across, it’s quite a stable situation. If you put the two pieces back together again and fire a couple of screws across them, it hold beautifully, the patient can move their ankle very quickly. It’s again related to the exact nature of the fracture. That fracture will be held very well with a screw. You don’t need to do anything more elaborate. When we get onto bigger implants, plates, multiple screws and rods, then the issue is that the fracture is unstable, and remember we talked at the beginning of this session about the difference between stable and unstable. An unstable fracture is one which is likely to deform over time if left without some sort of support, and the support usually would be metal that is laid either alongside the bone or inside the bone to hold everything in place; and that’s what it’s there for. It’s really temporary. It’s there for the duration of the healing process, and once the healing process has occurred that implant is no longer valuable, and sometimes may be causing trouble.

Dr. Sechrest: I think that brings up one important question that patients always ask and that is – do these implants need to come out? 30 years ago I think we pretty typically said expect another operation to go in and take the plate out or the rod out. Today I think that in general most people would say, if the implant is not causing a problem, we leave it alone, we don’t go back and take it out. We don’t do another operation just to remove the implant unless it’s bothering you.

Dr. Clough: I agree with you. I was taught, as you may have been, that we should take implants out and the reason was that they believed that there was a stress concentration at the end of the implant, so that the bone and the implant were quite rigid and then the rest of the bone was fairly flexible. So there was a rigid part and a flexible part and the idea was that at the junction there would be a concentration of stress and there would be a high risk of a fracture and honestly I haven’t seen that. You do see it very rarely, but it’s not a big enough problem for that alone to be a reason to take out hardware, and patients are very worried about taking out hardware. It’s one of the commonest anxieties about the treatment of fractures. What am I going to do? Is it going to hurt as much as the original operation? Is it a difficult operation? Is my bone going to break because the implant’s been taken out? I think that leaving the implant in is a great idea unless it’s causing symptoms, and they do quite commonly cause symptoms. So round about 1/3 of implants, I think, get taken out and I have to say also there is a re-fracture rate after removal of implants, so the bone underneath an implant is weakened and round about 1 in 10, somewhere round about that area of people who have a forearm fracture and the plate’s taken out, will have a re-fracture in the first 6-8 weeks after the plates have been removed. So it’s not something to be undertaken lightly and I think that people need to really consider carefully whether the implant should be taken out or not.

Dr. Sechrest: I think I would agree in terms of the implants. I think people should realize though that if the implant is causing a problem, and sometimes these screws will loosen, they’ll back out, they’ll begin to loosen up and be more prominent, and that tends to cause rubbing on tendons, muscles, bones, and sometimes all you have to do is take out the loose piece, you don’t have to take out everything. The same goes for rods. Sometimes they will tend to back out, they will tend to become prominent where they rub on things, and if they rub on things then you may want to have it taken out, but in general, no.

Dr. Clough: There’s a mysterious pain that disappears if you take out implants. We really don’t know what it’s from. I think it’s probably electrochemical, I think there’s probably just a little electrical current generated by the difference in the metal and the surrounding fluid. But for one reason or another a lot of people have an achy feeling in their limb that is often made worse by a temperature, when it gets cold, they feel the bones more acutely, and it’s subtle and they often don’t complain about it but if you ask them they’ll say, “yeah, it doesn’t feel quite right”, and if you take the plates out or the rod out that disappears. While I do agree that rods, and plates, and implants, in general don’t have to be taken out, I think that the operation is usually simple. I would always take all of the implants out if I’m there. I wouldn’t leave a plate in and just take a screw out unless there was a real, real difficulty about taking the whole thing because I think that some of the symptoms are from the metal joint fluid or body fluid and fracture.

Dr. Sechrest: Let’s move on and talk a little bit about prognosis and what to expect after treatment for a fracture. So if you’re treating a fracture without an operation, talk a little bit about the typical course of what a patient can expect from cast treatment. I mean, what does that really look like for a patient?

Dr. Clough: I’m going to divert a little bit from that into the biological events that occur at a fracture. When a bone breaks, the gap between the bone fills up with blood, and that blood very rapidly clots. A blood clot has very little strength, it’s about as strong as a piece of jam or a sponge. So that the first structure that’s between the bones is very weak, and the bones can move with no difficulty. But that blood clot attracts new blood vessels. So new blood vessels grow from living tissue into the blood clot and replace the structure that’s essentially dead blood, clotted blood, by a matrix of new blood vessels plus fibrous tissue. So the initial blood clot over the first 10 days or so is replaced by what really amounts to scar tissue and that scar tissue is relatively mature and quite a big stronger round about 10 days. So at about 10 days time you’ve got a rubbery feel to a fracture. You can move it a little bit but it’s actually quite difficult to pull apart or displace to a great extent and the scar then gradually transforms itself into bone. Really the only difference between scar and bone is that bone has mineral, calcium mineral, deposited in the scar tissue, and so some of the cells in the scar tissue between the fracture fragments form the ability to lay down bone mineral and that bone mineral stiffens the scar tissue so it stops being rubbery and bendable and it become hard and it is bone. That’s what happens. That’s the process and it takes around about 6 weeks for enough bone mineral to be laid down to be visible on the average x-ray. So getting back to your original question of what is likely to happen if you have a patient in a cast and the natural healing process is going on, you first off have a time when the cast is quite tight and swollen. For the first few days, there’s a lot of biological activity going in there, that limb can be quite swollen, and you may end needing to relax the cast or spread the cast a little bit so that the swelling can be accommodated and doesn’t get too tight, and then the swelling goes down. The activity gets confined to the fracture area, all the edema and tissue fluid that has spread out, the spilt blood, the torn areas, start to heal and shrink so the limb becomes smaller again. The cast often has to be tightened up at that point to keep the fracture still. Round about 3 weeks is often the time that the doctor will change the cast or take the cast off and have a look at it. It depends on the fracture, of course. But let’s say a wrist fracture, it’s not uncommon for people to change the cast at that point and take another x-ray and make sure that the alignment is still satisfactory and the process is going ahead. We can sometimes see, in children, we can sometimes see new bone formation at that stage. In adults it often takes longer than that. Round about 6 weeks, we can usually see on x-ray that there is new bone formation and that healing area now is strong enough that the cast is no longer necessary. Sometimes a cast is kept on for longer than that. In the leg it’s often kept on for longer than that because the forces are greater, but for a wrist fracture you may be able to take the cast off right about 6 weeks and allow movement of the hand and wrist to recover some of the stiff areas.

Dr. Sechrest: I think one of the things that people don’t sometimes understand is that even though the fracture heals at 6-8 weeks, there’s still this process of remodeling that goes on for up to a year, 2 years, I mean, sometimes even longer in some of the cortical bones, and that slowly that bone tries to go back to what to what it normally was and that remodeling process strengthens that bone and that last little bit takes a long time to get stronger. That’s true and very important. The bone that is formed initially is disorganized. It forms along the path of the blood vessels that have grown in, so it’s completely chaotic. It’s technically called woven bone which gives an idea of all sorts of strands of bone that go running in different directions. As you put stress on that area, the spicules of bone which are in the line of the stress, become thicker and stronger, and the spicules of bone which are running against the lines of stress get reabsorbed. So that over a period of time, and you can imagine, this is a very slow process, over a period of time the outer part of the bone which takes all the stress, becomes thicker and denser just like normal bone, and the inner part becomes thinner and comes to look much more like the inside of a normal bone. So that remodeling process can take up to 18 months, and if you plot the strength of a healing fracture against time, the first 50% of strength occurs in 6 weeks. The next 50%, let’s say up to about 80% of eventual strength, takes 3 months from the time of the injury, and 100% takes 18 months. So the first part is quite fast. The middle part is relatively fast and gets you to the point you where you can often use the bone again without serious risk of re-injury. But to make it feel normal again, to stop having aching, to stop having a process going on, that’s a long time.

Dr. Sechrest: It brings up another point that patients are always asking and that is, one of the common questions is: Will this bone be strong? Will it be as strong as it was before I broke it? Will it be stronger? What do you tell patients?

Dr. Clough: Well, I think it gets to be as strong as a normal bone. I’m not sure that if you did science on that subject you’d find that that was perfectly true, but I think you can say with confidence that people’s function will return to normal.

Dr. Sechrest: I think the other thing to that we ought to point out is the fact is it depends on how it heals. If it heals absolutely in alignment, absolutely normal, and it wasn’t displaced to begin with, it probably does get as strong as it was. The problem is that sometimes the way a bone heals, if it’s displaced and it doesn’t heal quite in the same orientation, again going back to mechanics and physics, the orientation of that bone now is more likely to fracture again.

Dr. Clough: Yes.

Dr. Sechrest: For example, you brought up the point of a stress fracture or a stress riser at the end of a plate or something like that. The same thing can occur when the bone heals a little bit abnormally.

Dr. Clough: You’re absolutely right, and I would say that a bone gives you normal expectations if it has healed in the anatomical position. You’re very right that there are two problems with healing in an abnormal, in an abnormal position there may be a concentration of stress which will make it easier to have a new fracture and the other is that by having the limb malaligned, you may put abnormal forces, and so people are more likely to trip, more likely to fall, to catch their foot and twist and give abnormal forces that will break the bone again.

Dr. Sechrest: Yeah, I would say probably, and see if you agree with this, I would probably tell patients that there is nothing about healing of a bone, the fact that you’ve had a fracture, that prevents you from having a completely normal strength bone at the end of that process. But there’s nothing that guarantees that either. There are too many other factors that come into play.

Dr. Clough: We can go back to our dinosaur, you know, that dinosaur that had 26 fractures lived and presumably functioned at an A1 level out there with nature, red, and tooth, and claw for years with all these healed fractures.