Treatment Options for Tibial Hemimelia

In the Illustrated Guide to Tibial Hemimelia, I discuss my daughter’s treatment journey for her condition. I also mentioned the controversy surrounding such treatment. Some doctors and parents believe amputation is the absolute right choice while others believe that a reconstruction is the best choice. And then there are people like my daughter who have had both options performed.

There are many reasons to decide for one treatment option over another. It is not always clear what these are or why each situation is different. There are often similar treatment options for Tibial Hemimelia (TH) and Fibular Hemimelia (FH).

I describe here what the issues are and what I believe are the most likely outcomes. These are all the things I wish had been explained to me as a parent before I went through the process. However, every situation is different and treatment options should be discussed with a real doctor. Hopefully the information below will help clarify the issues involved while showing how complicated the decision-making can be.

As I am an advocate for limb salvage, this is not an unbiased view.

The Primacy of the Knee

There are three types of amputations: below-the-knee, through-the-knee, or above-the-knee (through the femur). There have been extensive studies on energy expenditure costs associated with various types of amputations and reconstructions. Only below-the-knee amputations maintain a functioning knee and result in the best functionality and lowest energy expenditure. Above-the-knee amputations fare the worst in both energy use and function. In terms of function, through-the-knee is closer to above-the-knee than below-the-knee. However, through-the-knee amputations are closer to below-the-knee than above-the-knee in terms of energy expenditure. (I will add the journal article where I read this when I find it).

Next, the advantage of having one functioning knee over none is a much greater treatment objective than having two functioning knees over one. In deciding on treatment for FH and TH, the primary determining factor is whether or not a person has or can have one functioning knee. If the best long-term function is desired, a double through-the-knee or above-the-knee amputation should be avoided.

With only one knee a person can still perform most daily activities, such as walking up stairs, with minimal difficulty.

If the decision is between having one functioning knee or two, two is preferred. This is a controversial point due to the time, expense, intrusiveness, and complications of treatments.

If the knee is functional, then knee reconstruction surgery is not required, although an external fixator may still be required to align the bones or lengthen limbs in order to avoid amputation.

Bilateral or Unilateral

One of the most important distinctions is whether or not the deformity affects one leg or two. In unilateral cases, a person has a functioning knee that will serve them well no matter what the treatment decision is. Somewhat paradoxically, amputation of a deformed leg may be chosen in the unilateral case but not in the bilateral case if it is the best leg of the two. To quote Dr. Paley: “Let’s put our efforts into the good leg.” This is because of the primacy of a functioning knee.

For my daughter, we chose amputation for the worst leg because Dr. Paley could not, in good conscience, reconstruct a leg with such poor prospects. But the better leg could be reconstructed to provide a functioning knee. The only alternative was a double through-the-knee amputation.

In the bilateral case, amputation of one leg may be chosen to avoid limb-lengthening treatments. Having one leg in a prosthetic means that the prosthetic can be lengthened rather than the reconstructed leg. Nevertheless, choosing amputation just to avoid corrective surgeries is not normally considered a viable alternative in any other type of situation, so it shouldn’t be for TH either. (See the Fibular vs. Tibial Hemimelia section below).

Quadriceps

The length and size of the quadriceps muscle is of critical importance if the knee is not functional. If the condition of the muscle is not good enough, then the chance of an actively functioning knee becomes very low. In the unilateral case, the decision may be made to keep the leg because the good leg can make up for the deficiency of the other. In the bilateral case, amputation is typical as a prosthetic will provide superior performance. In general, however, amputation is the most likely outcome for a leg with a poor quadriceps.

Patella

The existence of a patella (knee-cap) is one of the determining factors in whether or not reconstruction of a non-functional knee is recommended. A patella is strongly desired for a successful reconstruction. While the quality of the quadriceps is the more significant determining factor, the patella is still important. In TH cases, the patella is flipped and fused to the base of the fibula to form a better, more stable, bone base. The patella + fibula become a replacement tibia.

Foot

While the knee is of primary importance, the foot is not. In TH and many FH cases, the ankle joint does not work. The solution is SUPERankle surgery, which fuses the foot in the flat plantigrade position. This provides acceptable performance in most cases, allowing amputation to be avoided.

Occasionally the foot is so deformed or painful that it must be amputated using a Syme amputation and prosthetic foot. If the amputation results in no pain, this is generally preferable to a below-the-knee amputation, among other reasons, because it requires lower energy expenditure.

The benefit of keeping the foot is proprioception. By being able to feel the ground, it is easier to keep balance, especially on uneven terrain. Amputations will result comparatively more falls.

Like any other foot deformity, there is normally no reason to amputate the foot unless all other options have been exhausted.

Limb-Length Discrepancy

If the two limbs have a different length, then the bone length must be adjusted to allow proper walking. Shoe lifts can help offset some of this, but limb lengthening is a longer-term fix. In almost all forms of TH and FH that don’t involve amputation limb lengthening is required.

Multiple treatments are required over the course of a number of years. The leg is fitted with an external fixator and the bone stretched at up to 1mm per day. This leads to some scaring, and there will be some pain healing from surgery, but the stretching is itself is painless.

Of all the treatment options described here, limb lengthening is probably the easiest to perform (it is slow, but not difficult). However, it is also the most time consuming and requires two surgeries for each treatment (to install and remove the fixator). Depending on the severity of the limb difference, a number of treatments may be required spaced out over a period of years. As with any surgical procedure there is a risk of infection, so proper wound care and hygiene is essential.

While it might take a long time and potentially cost a significant amount, it is also predictable and correctable. If someone broke their arm, they wouldn’t complain at having to wear a cast to fix the problem. Limb lengthening does indeed take longer, require surgeries, and have more complications, but it is just as correctable as a broken bone. Some of the unknowns include the long term (30+ year) side effects of limb lengthening. Since the treatment is relatively new, there is not a huge amount of evidence, but it obviously increases with every year. Your doctor should stay abreast of the latest research in order to make the most informed suggestions. The more significant the discrepancy, the more likely amputation will be recommended.

If the only issue is a length discrepancy, then the outcomes are often superior with treatment compared with amputation from both a functional and energy expenditure standpoint. It may end up being a choice between amputation to avoid surgeries, time, and cost over a better outcome.

Partial Bones

So far the discussion has centered around the most severe cases of TH. If a partial or deformed tibia is present, then both bones can usually be moved and resized to relative normalcy. This requires surgical correction and the use of an external fixator. It will often involve later limb-lengthening and a SUPERankle surgery. The outcomes in these cases are usually superior.

Tibial vs. Fibular Hemimelia

While the treatments for TH and FH are often similar, many FH patients only require limb lengthening (and the possibility of ankle surgery). Typically FH is much easier to correct, with better outcomes being the result. Unlike Tibial Hemimelia, reconstruction is almost always recommended for Fibular Hemimelia. Dr. Paley explains:

When pediatric orthopedic surgeons are asked “would you amputate the foot if all that was wrong with the leg was a foot or ankle deformity such as club foot or many other childhood foot deformities?” the answer is universally “no”. Despite this, the results of some club foot treatments leave the child with chronic pain and a stiff deformed foot that might be better treated by amputation and prosthetic fitting. When orthopedic surgeons are asked if they will amputate the leg of a child with no foot deformity and just a limb length discrepancy, the answer is almost universally “no”. When orthopedic surgeons are asked if they will amputate the leg of a child with a combination of foot deformity and limb length discrepancy, the answer is frequently “yes”. This doesn’t follow, since, for a foot deformity our standard answer is to perform foot deformity correction surgery, and for a limb length discrepancy our answer is to perform a limb lengthening surgery. Therefore, it does not make sense that when there is a foot deformity combined with a limb length discrepancy, the answer is not a foot deformity correction surgery combined with a limb lengthening procedure. What Dr. Paley recommends is exactly that: foot deformity correction with the SUPERankle procedure combined with lengthening using an external fixator.

Unfortunately, there are doctors that will amputate a leg with a minor foot deformity and only a 10-12% limb length discrepancy. As terrible as this is, and it is terrible, making the wrong decision does not have the ramifications it once did, because the quality of prostheses keeps getting better with time. In other words, medical care is good enough that both amputation and reconstruction result in positive outcomes. While some decisions are certainly better than others, it is sometimes unclear. And no decision should result in a lifetime of guilt, although some is probably inevitable regardless.

Thus the default treatment for Fibular Hemimelia should be reconstruction, with amputation selected if appropriate in the individual case. Reconstruction should always be given as an option for Tibial Hemimelia.

Therapy

No matter what decision is made (amputation, reconstruction, and/or lengthening), extensive physical therapy is probably required.

Conclusion

There are many different treatment options available. For Fibular Hemimelia, the condition is almost always treatable. The decisions with Tibial Hemimelia are much more difficult. One of the biggest problems is that the “best” course of treatment in theory may not turn out to be the best in practice. Everyone is different and results will vary. Amputation is quite permanent and there is no way to go back and do it over. Similarly, you can’t get the time and resources back from going the reconstruction route, although amputation is always a fallback option. In the end, you have to make up your own mind.