12/15/2021    Paul Kesselman, DPM

Best Treatment Option Status Post Transmet Amputation (Jeffrey Kass, DPM)

I see almost no value in stuffing a shoe with who
knows what materials, either on the advice of a
general or orthopedic surgeon as I have seen over
the past forty years. This almost never helps
patients and almost always creates more harm than
good. I have seen this overly simplistic attempt at
causing everything from mild inflammation affecting
the distal stump to frank ulceration.

To say nothing of the fact that this does nothing
to offer the patient any assistance in any gait
abnormalities which the patient may have.
This leaves the reasonable practitioner to
investigate whether a custom toe filler with or
without a carbon plate to stiffen the shoe is best,
or does the patient require an AFO with toe filler
with a stiff shoe plate.

In almost every TMA I performed, I also either at
the time of TMA or some months shortly thereafter
performed either a STAAT and T Achilles
Percutaneous lengthening. My patients were
counseled on this prior to the performance of the
TMA as part of a staged addressing of their issues
as well as discussing their gait assistive devices
prior to surgery. In many cases, this approach
afforded the ability to really keep things simple
and those patients in most cases did fine with a
custom made toe filler with carbon plate shoe
stiffener over the long term.

In those cases where the equinus and varus were not
surgically managed or could not be, an AFO with a
toe filler worked best, not perfect but as best as
could be expected.

Having seen many patients who underwent surgery
elsewhere, the last thing they want to hear is that
they need more surgery and in many cases the risks
are too high.

Certainly each patient needs their own independent
evaluation and let us not forget many of them have
mechanical issues which go beyond the lower
extremity.

Thus to simply catalog patients into one category
or another is no doubt over simplistic. The whole
package needs to be addressed.

Last but not least, don't overlook an examination
of the patient's shoes. That too many provide you
with invaluable information.

To sum things up, I think this is a great question
and I am looking forward to hearing from others on
providing their expertise and the offering of their
experiences.

Paul Kesselman, DPM, Oceanside, NY

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12/16/2021    Doug Richie, DPM

Best Treatment Option Status Post Transmet Amputation (Jeffrey Kass, DPM)

It should be recognized that the current preferred
treatment of the post TMA patient, using
therapeutic shoes with toe fillers is simply
inadequate. Consider a systematic review which
showed that one-third of patients undergoing a TMA
will require a more proximal amputation of their
affected lower extremity within 5 years. (Thorud,
Jakob C.; Jupiter, Daniel C.; Lorenzana, Jonathan;
Nguyen, Tea Tu; Shibuya, Naohiro. Reoperation and
reamputation after transmetatarsal amputation: A
systematic review. The Journal of Foot & Ankle
Surgery;2016, 55: 1007–1012)

There are several reasons for the high ulceration
rate in patients who have undergone a TMA
procedure. Studies have documented high plantar
pressures in the residual foot compared to the
contralateral foot in TMA patients. This may be
related to substantial gait disturbances which have
been observed in TMA patients. Mueller and co-
workers studied patients with diabetes and TMA and
found less range of motion, lower peak moments and
diminished power at the ankle compared to age
matched controls.

(Mueller MJ Salsich GB, Bastian AJ. Differences in
the gait characteristics of people with diabetes
and transmetatarsal amputation compared with age-
matched controls Gait and Posture.1998;7: 200–206)
In this same study, the TMA patients had only 25%
the push-off power of healthy controls.

One of the significant changes that occur after
forefoot amputation is the shortening of the
plantar flexion lever arm of the triceps surae
acting on the foot. Another factor is the loss of
tendon attachments at the toes, and sometimes
within the mid-foot creating a functional dropfoot
condition. An imbalance occurs where the tibialis
anterior muscle overpowers the peroneus longus and
inverts the foot ,creating a varus deformity.

Stiff rocker soles are thought to help offset some
of these structural and functional changes after a
TMA, but they do not adequately replace the
imbalance and loss of the ankle joint plantar
flexion and dorsiflexion muscle-tendon units.

That is why a system which incorporates a carbon
fiber AFO with a custom foot orthoses and toe
filler can address all components of the
biomechanical deficits seen in the post TMA
patient. A carbon graphite ankle-foot orthosis is
capable of maintaining ankle joint dorsiflexion
during swing phase while providing dynamic recoil
at late mid-stance to aid in push-off during the
heel rise phase of gait. This type of ankle foot
orthosis contains a full length carbon graphite
foot plate to re-establish and lengthen the lost
lever arm for ankle plantar flexion seen in TMA
patients. The solid connection of the lower leg
portion of the ankle foot orthosis to the full
length foot plate facilitates the “third rocker”
phase of gait which is lost in the TMA patient. A
custom molded partial foot orthosis with toe filler
and medial posting is the second component of the
system to provide total contact off loading of the
residual varus foot for reduction of plantar
pressure and tangential shear force.

Finally, properly fitted footwear is essential to
accommodate this orthotic system and address the
needs of the contralateral foot.

Disclosure: I am the owner of Richie Technologies
Inc who distribute carbon fiber ankle-foot orthotic
systems.

Doug Richie, DPM, Long Beach, CA