Saving Little Legs -- In-Depth Doctor's Interview

Interview with Mark Barry, M.D., a pediatric orthopaedic surgeon in Las Vegas, Nev., explains rotationplasty.

What is rotationplasty?

Dr. Barry: Basically, rotationplasty is a type of surgical procedure that we do on relatively young children to treat various conditions; the most being bone cancer, bone tumors where we try to save as much function in the leg after removing the bone tumor. The other indication for rotationplasty is done with kids that are born with birth defects where a leg doesn't form normally. For example, the femur doesn't grow and it's an excellent procedure to maximize the children's function for those indications.

Can you explain what you did with your patient Isaac?

Dr. Barry: Well, Isaac when I met him he was four-and-a-half years old and he had been experiencing about two to three months of pain in his leg, diagnosed to have an osteosarcoma. An osteosarcoma is a malignant bone tumor, the cause of which we don't know. Here's an X-ray of his left femur, his thigh bone, and this shows the tumor at the lower end of his femur. Here's his knee joint and you can see how this tumor essentially expands. The bone forms new bone and causes erosion throughout the area. Essentially, that's the painful tumor that presented with us and was ultimately biopsied and anatomically shown to be a malignant bone tumor.

And Isaac was only four at the time?

Dr. Barry: He was four-and-a-half when I first met him and we biopsied him and after the biopsy he underwent approximately three months of preoperative chemotherapy, which essentially shrinks the tumor and allows me to do my job to get around the tumor more easily, more predictably. The whole principle being to remove the tumor from his leg, leave no tumor cells behind and then rebuild his leg as best possible to give him the best long-term function.

What did you do then?

Dr. Barry: Basically, what I did is best explained by the shots that we did with Isaac in terms of how his leg works, but on X-ray here's what we did. We had to cut through the thigh bone at this level because the tumor extended on MRI; the tumor extended all the way up the middle part of the bone, up into this level approximately here. We had to cut through a couple of inches above and cut through his tibia bone just below his knee joint, at this level, and remove all of the tumor. That left us with a big gap. So in older children we can fill that gap with an artificial knee joint; a metal artificial knee joint with a hinge. In younger kids we can't because we have the problem of removing the growth plates around the knee joint. So here's a child who is four-and-a-half years old. If we remove the growth plates basically by the time he was mature, his leg would be approximately five to six inches shorter than it would be otherwise. So we're left with a dilemma of how to give this child the best function in light of this situation.

When we're faced with this issue in the past, 15 to 20 years ago for example, kids would have had what is called a high-thigh amputation. The artificial let would have to fit onto a short stump of the leg and basically their function would be very limited. They would have a difficult time with, with prolonged walking, endurance. They couldn't run. They would have a tough time playing and things like that. So by doing the procedure that we do for these young children -- the rotationplasty -- we use the lower part of the leg, which is normal. There's no tumor and we assess that prior to the operation with various scans. For example, a bone scan. We remove the tumor through this region. We save the artery, the vein and the main nerve, the sciatic nerve. We can dissect those away from the tumor and then we take the lower leg segment, turn it 180 degrees and then attach it to the femur bone. This X-ray here shows the short part of the upper femur bone, the hip joint, and this is in fact the tibia of the lower leg that's attached with this plate and screws. So that's how we attach the lower leg, turned around 180 degrees backwards onto the femur to allow the ankle joint to function as the new knee joint and power the below knee artificial leg.

What does this treatment do for children?

Dr. Barry: Basically, its saves them an extra functional joint. So instead of this high-thigh amputation, which is functionally not as optimal, we get a below knee -- effectively a below knee amputation, which gives them an extra joint to power his artificial leg. The other thing we do we save the sciatic nerve so that these kids don't have phantom pains. So with this extra joint and a below knee artificial leg, the kids are able to walk better, have greater endurance. They are in fact, able to run, jump, play and essentially lead fairly normal lives. Doing this procedure on kids at a very young age, psychologically they adapt very well.

Are there any downsides to this procedure?

Dr. Barry: We find that when this procedure is done on young kids, they adapt fairly well both physically and psychologically. There have been studies that show that these kids really do well in the long run and don't really have any long-term serious psychological issues. They adapt quite well.

Are there any downsides at all?

Dr. Barry: They do have an artificial leg -- a prosthesis, which can break down from time to time, so they establish a good relationship with the prosthetic fabricators who probably have to change out this artificial leg every two or three years. They have to lengthen it as they grow.

But they would have to do that if they had a high-thigh one as well.

Dr. Barry: Yeah, change it out every few years for wear and tear, but those are the issues that these kids face. But otherwise, their prostheses are generally very comfortable. Some of these kids run in long distance races. They do a variety of sports, like basketball and track and swimming and things like that. They really function quite well.

So Isaac is going to have a pretty good life ahead of him?

Dr. Barry: He should. So far we're a year-and-a-half out. He has excellent function and we monitor various studies and scans to check and make sure that the tumor is not coming back and so far he's clean. And we're really optimistic that he'll do well and he'll have a very functional life.

He's always got this great smile on his face. He's just such a resilient kid and great family. I'm just excited to see him every time he comes into the office because he's such a positive, positive little guy and he's done so well. He's just an amazing little child.