You may hear about this mysterious thing that will happen at some unknown point in the future after your child's foot is corrected with Ponseti casting called "heel dropping". But what is that and what does it mean? Doctors can be super vague about this, but will tell you with great certainty that it will happen, and then promptly walk out leaving you wondering what the heck that means.
Does it mean the heel bone will magically drop into place at some point someday?
You may be wondering why they wouldn't just put it in the right place in the first place, isn't that what Ponseti casting is all about?
You may be wondering why it doesn't happen right away, or curious when it will happen. Many parents aren't even informed about this and haven't been told about the heel dropping at all.
If you're lucky, you may have been told that only half the hole needs to be filled, but not exactly WHY that is ok and what is the difference between half the hole and only a sliver of the hole being filled, and what the difference is between a foot lifting up and not filling the whole hole, and one that solidly fills half the hole.
Below we will discuss and hopefully clear up the whole heel drop mystery.
When the clubfoot is first corrected, the heel of most clubfeet does not appear normal or the same as the other non-clubfoot. As I understand it, this is due to the re-positioning of th calcaneus (heel bone) after correction, and the fact that the heel pad tissue simply is hanging out being heel pad tissue without a purpose waiting to be normal while the calcaneus is in the incorrect position (clearly this is a personal interpretation of what the heel pad tissue is doing, as if it was alive. Which of course it is not,and it isn't just waiting tapping it's foot like "ok calcaneus, get into position so I can be normal!").
Once the calcaneus is positioned correctly, the heel pad tissue begins to normalize and take a more typical shape. This can take some time, either a few weeks or sometimes more than a few weeks. Occasionally it can take maybe a couple months or so, but in these cases usually you will see some kind of change at least beginning before it's fully dropped.
Clubfoot heel before the heel has "dropped"
Non-Clubfoot Heel
So what is heel dropping? It actually is quite simply heel pad tissue normalization. There are no bones or structures in the foot that actually "drop" or move or actually DO anything other than become normal in both appearance and sensation when palpated. The squishy empty feeling will disappear as the heel "drops", and then it's dropped and looks pretty normal. Generally overall the clubfoot heel will always be just a little different than a normal heel, and it may take more time than just the first few months for it to become completely normal in appearance. It is not uncommon for the heel to be more pronounced in the clubfoot, with a bit of a dimple or a crease above the heel pad. This is why clubfoot shoes for bracing have a deep heel pocket.
The heel pad is a very complex combination of many different kinds of tissues, and in this combination the heel pad is what protects the calcaneus (heel bone) from having to make direct contact with the ground which would be excruciatingly painful. The heel pad is a very robust bit of fat and tissue (surrounded by muscle fibers) that needs to last for a lifetime of use, supporting all sorts of various weights that a human may find themselves at, and being the only buffer or cushion between the earth and the heel bone (calcaneus).
There is no set time for the heel to drop, but normally it will happen within the first month of bracing after the foot is corrected with Ponseti casting. It can take longer than a month, and sometimes parents report it happens within a week or two. The general consensus is that it will happen within the first three months after casting is complete, normally much sooner than that.
There is nothing you can do to speed up the process of the heel dropping. You just have to wait, and please try not to worry about it because there's really nothing you can do or not do that will make or break this process.
If the squishy empty heel persists beyond 3-4 months post casting, talk to your Orthopaedic Surgeon. Normally they will have noticed this long before you do anyway. True empty heel is rare, but does happen sometimes, and is usually associated with an incorrectly corrected calcaneus bone.
True empty heel is a condition that tells the doctor that the calcaneus bone has not been placed in the correct position. When this bone isn't in the normal spot, the heel pad remains soft and squishy well beyond the time that it should have normalized. Generally there will be some other indicatiors of the foot not being properly corrected well before months down the line when you discover the empty heel. Also, the doctor should know the difference between a normal squishy heel post casting and a true empty heel but it's not uncommon for the doctor to misdiagnose empty heel, or not understand it well enough. There are a few papers that look at this on the studies pages.
"The heel pad lies between the calcaneus and the skin and consists of neuronal, vascular, fibrous and elastic components intertwined with fat cells"
Jahss MH, Kaye RA, Desai P, Watkins FB, Michelson JD, Kummer FJ. Histology, Histochemistry and Biomechanics of the Plantar Fat Pads In Disorders of the Foot and Ankle Medical and Surgical Management Second Edition. Volume III. The curtis center, Independence Square West, Philadelphia PA 19106: W.B Saunders Company Harcourt Brace Jovanovich, Inc; 1991. pp. 2753–2762.
