Regrowing My Tibia - Part One

I have had my external fixator for two and a half months. In that time, it has been the primary focus of many of my blog posts. This makes sense because, quite naturally I think, it has been the primary focus of my life. It would be pretty strange if the shiny blue piece of metal sticking out of my leg didn't garner at least some of my attention, right? What does seem strange to me, however, is that I haven't taken the time to actually explain how the whole external fixator, re-growing bone thing works. So explaining that will be the focus of today's post.

I have been confronted with a large and often confusing set of terminology since being introduced to the idea of external fixation after surgery number four at the end of August. When I say introduced it makes it sound like I had other options to consider and that I could choose which one I wanted. This is false. I had no choice; this was my only option, so not only was I trying to understand a whole lot of new terminology and grasp the process in general, but I was also trying to wrap my head around that it would actually be happening to me. Some of the concepts I am going to describe are rather hard to grasp - even my surgeon admits they doctors themselves do not fully understand how concepts, like regrowing bone, work - so please baear with me as I try to explain and translate some of the medical mumbo jumbo into words we, myself included, can all understand. Hopefully this doesn't come across as pure gibberish.

Because regrowing bone is a complicated process, I will be breaking this topic down into two separate posts. For starters, I will define the core terms and concepts that govern regrowing bone; the next post will go into my x-rays and what exactly my doctors are doing to me. Gee, that makes it sound like I am some sort of lab rat...

Here we go!

Osteotomy - surgically procedure to divide a bone or cut out a piece of bone. Osteo = bone; otomy = to cut.

Distraction osteogenesis -  a process in which two pieces of bone are slowly moved apart in order to tempt cells to bridge the gap, therefore allowing new bone to grow and/or a limb length discrepancy to be corrected. According to a quick Google search and the Seattle Children's Hospital, "a procedure that moves two segments of a bone slowly apart in such a way that new bone fills in the gap".

Bone transport - same thing as distraction osteogenesis. In fact, some sources describe the entire process as bone transport distraction osteogenesis. But just to make it confusing, other sources refer only to bone transport while others to distraction osteogenesis alone, and a good chunk more use the terms interchangeably. It is the process of moving, or transporting, bone.

Lengthening progressive or progressive lengthening - pretty much the same as both distraction osteogenesis and bone transport. Confusing, right? The progressive part refers to it being a gradual, continuing process. The parts of the bone are pulled apart at a controlled rate, usually 3/4 to 1 mm a day over a period of time (however long it takes to grow the desired length of bone).

Eternal fixation - a process used to stabilize fractures, correct deformities, malalignments and/or limb leg discrepancies, and to regrow missing sections of bone. The use of pins, wires, clamps and rods to stabilize a bone at a distance from the area that was deformed, broken or operated on. This process requires an external fixator.

External fixator - a device made of a series of pins, clamps and rods. It is constructed around a patient's limb and attached to the bone through a series of pins and/or wires. Basically, pins, (which are like giant screws) that stick through the skin are drilled into bone above and below the fracture/malformed/etc. area, and a metal device is attached to those pins/screws on the outside of the body. Any corrections that need to be made to the bone are done by adjusting the external device.

Docking site - when the piece of bone being transported reaches its destination (the end of another piece of bone), this is called the docking site. The ends of the two pieces of bone must knit together, just like a broken bone would need to do in order to heal. Because this is the last step in the bone transport, this is the final area to start healing.

Dynamization, compression or compressive loading - once the desired length has been achieved, the bone is lengthened a little bit more, thus putting pressure on the new bone, which enhances healing. I have no clue how this works. My surgeon tried to explain it, but according to him even the medical people are still out on what actually occurs.

Intramedullary rod - aka. intramedullary nail or IM nail. A metal rod forced into the medullary cavity (central shaft) of a bone. It is secured in place by several screws at either end of the rod/bone. This device is used to stabilize fractures internally, to share the load/weight with the bone, and to speed up the recovery period and reduce the amount of time patients are off their feet. This is a form of internal fixation, meaning it is inside of the body, in contrast to external fixation which is described above. Not everyone who requires an external fixator needs an IM nail and vice versa.

Bone graft - using bone from another area of a person's body or from a donor to replace missing bone. According to Wikipedia (because I am being as incredibly thorough and academic about all this), "bone grafting is a surgical procedure that replaces missing bone in order to repair bone fractures that are extremely complex, pose a significant health risk to the patient, or fail to heal properly. The Free Dictionary defines it as "a surgical procedure by which new bone or a replacement material is placed into spaces between or around broken bone (fracture) or holes in bone (defects) to aid in healing.

And that is that. I think I have briefly summed up the gist of it. The process and the main definitions are covered - basically a bone is cut into pieces, an external fixator applied, adjustments made to the fixator every day, and voila, new bone is grown! Except it's not that easy. It sounds like it, and in theory it is, but it is quite brutal, painful, and time-consuming for the individual going through it, not to mention emotionally and psychologically draining. Even experts in this kind of thing have likened it to medieval torture.