How To Modify Orthoses For Plantar Fibromatosis

Prescribing orthoses for patients with plantar fibromas can be challenging. In general, our treatment goal is to reduce tension on the plantar fascia and then reduce pressure on the plantar fibromas. This can lead to a catch-22 situation as orthoses that conform closely to the arch of the foot can help reduce tension on the plantar fascia but they may also increase pressure on the fibroma. Luckily, there are some fairly straightforward orthotic modifications that can lead to an excellent clinical outcome for these patients.

To decrease plantar fascia tension, you will want to prescribe the initial orthosis so it conforms closely to the arch of the foot when casting the foot in a neutral position with the first ray plantarflexed. This will result in a device that conforms very closely to the arch of the foot and will help decrease flattening of the foot, which in turn will decrease tension on the plantar fascia. We also would recommend a wide orthosis so the orthosis acts to spread force over a larger surface area. If the heel is everted in stance or in gait, you will want to incorporate prescription items that will limit heel eversion. For example, this might include a deep heel cup and a medial heel skive.

You also want to prescribe a topcover with a bottom layer of cushion and a top layer that you can modify with a grinder to create a pocket for the plantar fibroma.

Once you receive the orthotic back, you can add an accommodation for the plantar fibromas directly into the cover. We recommend that you do this in the office where you can ensure that the accommodations are exactly in the right position. The easiest way to do this is to mark the plantar fibromas with lipstick and then hold the orthosis up to the foot so the lipstick transfers to the topcover. It is then quite simple to grind the accommodation directly into the topcover. After adding the accommodations, you can add a final, extremely thin cover on top of the current cover to finish the device.

We recommend against adding the accommodations for the fibromas directly into the orthotic plate. Not only does this increase the rigidity of the orthotic plate but it is actually very difficult to get those accommodations in the exact position when having to transfer the marks from the foot to the negative cast to then to the positive cast and finally into the orthotic itself.

Editor’s note: This blog was first published at https://www.prolaborthotics.com/Default.aspx?tabid=90&EntryID=378 and has been adapted with permission from Lawrence Huppin, DPM, and ProLab Orthotics. For more information, visit www.prolaborthotics.com .