02/23/2016    Don Peacock, DPM

Non-Responsive Plantar Fascial Pain

The symptoms suggest a neurological component to
your patient’s pain. It's probable that an
impingement of nerve structures in the tarsal
tunnel area is the culprit. It is also possible
that there is a concurrent impingement dorsally
in the deep peroneal which can lead to allodynia.

Specifically, the pain distribution makes it
highly suspect that the impingement is at the
porta pedis. If you press hard with your thumb in
this area it should illicit pain but no
necessarily a Tinel's. I would suggest an
anesthetic block at the porta pedis and give it 5
minutes to see if the pain resolves. If it does
there is entrapment at the porta pedis. Nerve
impingement is seen here more frequently with
patients that have a flexible rear foot and
flexible forefoot foot-type. If the pain does not
resolve precede to block the deep peroneal as it
courses between the 1st and 2nd metatarsal bases
dorsal. Other nerve areas and branches around
the heel can lead to pain so several superficial
blocks may help pinpoint the etiology.

Treatment will vary with these patients. If the
biomechanics are the root issue then stenting the
STJ in a flexible rearfoot type will open the
tarsal tunnel 16% and may give relief. Similar
results maybe possible with a custom AFO. In
other foot types decompression will be the best
choice combined with stabilizing the foot
biomechanics either with conservative or surgical
options.

The Baxter nerve entrapment can come into play
here and releasing this area is a potential
treatment. Caution should be considered when
performing plantar fascial releases in flexible
foot types since this leads to destabilizing the
foot and increases the likely hood of further
impingement and other deformities such as PTTD
etc.

The anesthetic blocks will help you the most in
finding the etiology. Reliance on MRI and nerve
studies may lead nowhere with this type patient.
First, get the anesthetic trigger point diagnosis
done in order to help you make a good decision
with your treatment plans. Ultrasound with
measurements of the (ABC) zones allows for
staging plantar fasciopathy. If no thickening is
seen then that would definitely suggest a nerve
issue. Barrett has a nice staging protocol for
helping determine surgical vs. conservative
roadmaps that may help you as well. There is a
lot to consider with non-responsive heel pain and
it can be challenging. Good luck and I hope your
patient gets better.

Don Peacock, DPM, Whiteville, NC

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02/23/2016    Michael M. Rosenblatt, DPM

Non-Responsive Plantar Fascial Pain

Any patient with recalcitrant pain that is not
"well managed" by the usual patterns of podiatric
care should be evaluated for a general medical
condition. For example, hyperuricemia is usually
thought of as resulting in pain that affects
joints, and for the most part that is true. But
there can be atypical presentations of pain
caused by hyperuricemia, and this includes
heel/plantar fascia pain.

A common pattern for patients with gout is
excessive use of ETOH. This causes dehydration
and major shifts in uric acid metabolism.
Sometimes patients with extremely high
cholesterol and fatty acid lab reports see
"unexpected and not usually connected" symptoms.
I have seen patients with foot and leg pain who
never really got that improved until their serum
cholesterol was finally controlled. There is no
obvious connection of course. But I have seen
this happen.

At the very least, a uric acid and BUN should be
taken and evaluated. In addition, sometimes it is
necessary to call in a referral to a
rheumatologist. You don't want to be in a
position to miss an important systemic diagnosis
when you see atypical patients.

Also, it is helpful to share the concept of
"time-delayed diagnostic patterns" with your
patients. This means that sometimes a diagnosis
will not be fully recognized (or mature) until a
period of time has elapsed. Eventually the
patient sees a doctor who "gets it right." But
not all disease patterns present themselves
completely without a period of time elapsing.
Multiple sclerosis is one such disease, but there
are others.

I'm not saying this patient has MS. What I am
saying is that it often helps to have consults in
cases like this, and explaining to the patient
that not every disease has the same "time clock"
of presenting completely at the first or even
second exam.

Michael M. Rosenblatt, DPM, San Jose< CA