Why "Plantigrade" is a Failed Measure of Success

In every case of a child with club feet, the primary goal is to get the feet/foot plantigrade. That is, to get the sole of the foot on the ground. While there are many therapies and surgeries employed to that end, it is plantigrade that remains the goal.

On its face, this can seem like a logical and desirable goal. It has the effect of making the child's feet look like anyone else's feet. It makes it possible for the child to wear somewhat normal footwear. And, to be frank, the feet just look better that way.

But as a measure of success of all the surgeries and therapies? In a word, no. Let me explain.

How something looks is not necessarily how that same thing properly functions. Nowhere is this more true than in human biomechanics. Each bone, joint, muscle, tendon, ligament, fascial band, nerves and blood supply that enable and nourish those same structures, all are designed to work in specific ways that support adjacent structures, that is, parts above and below any given joint, to, in concert, allow effective, minimally energy intensive gait. Or, simply put, all the parts need to work in a particular way to allow normal walking, running, or other physical activities.

From the start, the club foot alters this desired relationship, creating what is known as pathomechanics - biomechanical relationships that create pathology, or trauma. One dictionary states trauma is " A serious injury or shock to the body, as from violence or an accident." However, trauma also results from slow, repetitive pathomechanical "insult" to the body, or parts of the body, that eventually becomes a serious situation for the body to manage.

Getting the foot merely plantigrade, with little or no consideration for the function of the subtalar (rearfoot) and mid-tarsal (mid foot) joints leads, almost inevitably, to trauma for the adult with post-club feet. This is because the subtalar joint, in particular, is critical to all the joints proximal, or above that joint, as it is the only joint in the body capable of supplying motion in all three planes of motion. It allows the leg above it, and the pelvis and torso by extension, to rotate on the foot as the foot is fully weight bearing against the ground. Without this function, the rotational forces would cause the ankle, knee, and hip joints to try to supply that rotation, which none of those joints are designed to supply. This, inevitably, leads to trauma in those other joints.

But it is not merely joints proximal to the subtalar that suffer - it is the subtalar joint itself. If there is inadequate range of motion in the subtalar joint, that joint itself suffered trauma. And over time, the joint becomes painful and eventually, develops osteo-arthritis as well as loss of cartilage, which in turn causes more pain, more inflammation, further breakdown, all in an endless cycle. And the only solution the orthopedists seem to have is to do a triple arthodesis - a fusion of the subtalar and midtarsal joint interface to prevent all that painful motion from occuring. The problem with that is, well, remember all those proximal joints? That cannot supply rotational motion? They are now forced to try and supply such motion. Which, as already noted, causes trauma to THOSE joints, and now your problem isn't just in your feet, its in your ankles, knees, hips, lower, mid, and upper back. Get the picture?

It is beyond time for the surgeons to step back from their techniques and look seriously at how they can improve the picture for the subtalar joint when doing club foot alterations. It may be, for example, that they should consider holding off on some of the surgeries until the child's skeletal structure, especially in the foot, is more fully formed, which would allow better assessment of the subtalar joint's condition - its range of motion pre-surgically, its joint surface congruency, its ability or inability to manage the repositioning of the foot with proper ligamentous and muscular opposition. And, if they spend the time to look at adults with post-club feet, who are, sadly, a walking (or limping) laboratory of the outcomes of prior surgical techniques, they may just come up with many more ideas than these.

The bottom line is simply this - the measure of success for club foot intervention must cease to be merely plantigrade. It must instead become a full assessment of the resultant biomechanical integrity of the child's foot or feet as they relate to the rest of the child's body, as it is designed to function, in motion as well as at rest.

Anything less cannot be called success.