Prosthetic Options for Difficult Amputations

For prosthetists, a multitude of factors influence the complexity of a
case. Many different pieces of the equation must be considered before devising
a treatment plan and selecting an appropriate prosthetic design for an
individual patient. The assessment period represents the first crucial part of
the equation and can determine the difficulty or complexity level.

“We spend a lot of time during the assessment period, and we try to
look at the patient through at least four different lenses,” John
Miguelez, CP, FAAOP, president and senior clinical director, Advanced Arm
Dynamics, told O&P Business News.

The first lens focuses on the patient’s psychological status and
examines issues such as how the patient is coping with limb loss and whether
other things are going on in the patient’s life that could impact the
rehabilitation plan. The second lens views the different prosthetic options
that are available for the patient’s amputation level. All of the
different types of prostheses — including the option of not wearing a
prosthesis — are described and then related to the patient’s
short-term and long-term goals. The ultimate goal is to find a solution that
allows the patient to return as closely as possible to his or her
pre-amputation lifestyle.

Image: Scott Sabolich

The third lens focuses on what is needed therapeutically to help
patients maximize their rehabilitation potential and determine their best
option for success. Finally, the fourth lens encompasses spending time with
patients as well as their families and friends to identify all of the things
that are going on in the patients’ lives so that the treatment
recommendation is as comprehensive and global as possible.

“Our team is never able just to look at the amputation and have
that be the sole determinant,” Miguelez said. “A well-healed,
healthy-skinned midlevel transradial patient who has some psychological
challenges, or some learning issues, or some family issues going on can be as
challenging as an interscapulothoracic level patient with a lot of scar

Psychological vs. physical factors

Complexity can involve psychological factors such as high levels of
expectation; personality issues including stubbornness or distrust; and
physical factors such as severity of injury, late complications and negligent
self-care habits. In fact, the ability to predict the complexity of a certain
case is often not possible on initial evaluation, said Zach Harvey, CPO, chief
prosthetist at Walter Reed National Military Medical Center (WRNMMC).

  John Miguelez
  John Miguelez

“At WRNMMC, the complexity of care includes the sheer volume of
multi-extremity amputation patients, the high expectations based on close
proximity of other successful prosthetic users and what we call prosthetic
envy, the complications of blast injuries such as traumatic brain injury or
heterotopic ossification and a patient population of previously healthy,
active, young adults ambitious to return to high levels of activity,”
Harvey told O&P Business News. “These demands require a
great deal of time to manage and do not discriminate based on the level of

Some physical factors that play into the equation in addition to
heterotopic ossification involve problems with fragile skin, scar tissue, bone
spurs and neuromas. In addition, the shape of the residual limb may make a
certain case complex. A patient who presents with a congenital condition will
have different issues than a patient with a trauma-related or disease-related

  Zach Harvey
  Zach Harvey

“Sometimes in congenital cases, the shape or presentation of the
limb may be a little more unusual than an amputation that has resulted from
vascular disease or cancer where normally in that case, it is a very clean
amputation and there is minimal scarring to deal with,” Jason Lalla, CP,
Next Step Orthotics & Prosthetics, said. “All of those factors really
come into play and certainly can make things far more complex.”

Limb length also can increase the level of difficulty when fitting
patients with a prosthesis. Usually, two-thirds the length of any bone is the
ideal length for fitting and offers the greatest chance of success, according
to Scott Sabolich, CP, LP, owner and clinical director of Scott Sabolich
Prosthetics & Research.

  Jason Lalla
  Jason Lalla

“Any longer than two-thirds the length of the bone is difficult to
fit; any shorter than two-thirds the length of the bone is difficult to
fit,” Sabolich told O&P Business News. “The length needs
to be just that prime optimum green light region of limb between one-half and
two-thirds length. Any longer than that is bad, and any shorter than that is

The presence of pain also can be a complicating factor. Patients can
have residual nerve pain or even phantom pain in the limb, which can be related
to neuromas, the way a nerve was cut or even a stitch that went through a

“Typically, here at our facility, we do not see the perfect half to
two-thirds length limb with no neuromas, no bone spurs, no scar tissue, no
heterotopic ossification, no anything, just a perfect limb, because they can
usually be fit locally,” Sabolich said. “It is when you run into
problems like these that patients start seeking out some of the destination
facilities and go somewhere with some experts who can handle the hard to fit

Multiple extremity involvement

Multiple amputations always increase the level of complexity. For
patients with multiple extremity involvement, donning and doffing a prosthesis
can be challenging and must be considered when planning the prosthetic design.

  Scott Sabolich

“You can sometimes design the best fitting socket possible, but if
the person is not able to manage the donning and doffing, then you have missed
the mark,” Lalla said.

Harvey recommends figuring out the patient’s weakest link and then
addressing that aspect of their lives. For example, household ambulation can be
a problem for patients with multiple amputations.

“I was highly focused on providing the best pair of legs I could to
a quadrilateral marine for community ambulation, but I neglected the fact that
at home, he was bound to a wheelchair and had difficulty pushing his wheelchair
when not wearing arm prostheses,” Harvey said. “We came up with the
idea of making him easy to don and doff household shorties that addressed this
aspect of his life. The first weekend he wore them, he told me that he cleaned
his bathtub, took out the trash, and most of all, his wife thanked me because
he was able to move around the house without her help. Since then, I have made
‘house legs’ for many of my patients desiring more independence
around the house.”

Increase Your Treatment Options With Targeted Muscle

As new technologies continue to emerge in upper limb
prosthetics, one option for some patients is Targeted
(TMR). John Miguelez, CP, FAAOP, president and senior
clinical director, Advanced Arm Dynamics, discussed the advantages and
challenges of this innovative procedure.

“One of the newer and more promising options for some
patients is TMR surgery, which actually reinnervates muscles so that there are
multiple EMG sites,” he said. “Up to eight outputs or eight different
signals can be gathered from the patient’s residual limb. This can allow a
patient to have much more control of their prosthesis and improve their
functionality. Of course there are also some challenges that are unique to TMR.
After TMR surgery, the involved tissue becomes hypermobile so that when the
patient contracts a muscle, much of the reinnervated tissue moves. This can
present extra challenge in establishing a good, stable interface and keeping
the electrodes in contact with the skin.“

The post-surgery recovery phase extends for several months
as the muscles become innervated. “During this time it’s important
for the patient to have therapy to learn how to access the muscles and be able
to contract them independently,” Miguelez said. “Although therapy is
a vital part of every upper limb patient’s success, it is even more
crucial in TMR where patients are going to really benefit from developing these
additional degrees of control.”

After the muscles are reinnervated, Miguelez said he may see
a patient weekly for therapy, fitting different sockets, or adjusting the
electronics or electrodes. He said the muscles continue to move and adjust for
up to eight months, so there is usually a need to make adjustments to the
prosthesis as the months go by.

“Having a comprehensive team of clinicians that work
with the patient and take the time to listen and work with the patient allows
the fitting process to go much smoother for the patient,” Miguelez told
O&P Business News. “For certain patients, it’s a
great solution. For other patients, there are different solutions that might be
more appropriate.”

Miguelez empahasized taking time during the assessment
period to truly understand the patient’s goals and devise a custom
treatment plan. He suggested using a simple checklist as a starting point to
approach the TMR process.

His team is involved at the outset of TMR surgery. “We
will see a patient and based on their limb presentation and their goals, decide
that they might be a candidate for TMR surgery. If we think that that’s
the case, we’ll meet with the surgeon to discuss, and then meet with the
patient and the surgeon together. There will be times when we might go with the
patient to surgery, but more often we facilitate that,” Miguelez said.
“Our goal is to try to educate the patient as to what the options are in
terms of prosthetics and allow the surgeon to do what he needs to be done to
maximize the patient’s rehab potential.

“Some people wonder if age is a consideration in opting
for TMR. I would say that age is really not a major factor. It just depends on
where the patient is in terms of their life cycle, their goals and what support
they have around them,” he said.

One area in which researchers are improving outcomes in TMR
surgery is pattern recognition, which involves multiple electrodes within an
interface. “We’re starting to look at the unique EMG signature of
muscle contraction and harness this information using a computer to controls
certain grip patterns and prosthetic functions. There is a lot of managing of
the electronics both from where the electrodes are located, to programming the
graphic user interface for optimal control, to socket design considerations, to
training the patient.” — Mary L. Jerrell, ELS


Certain projects can be complex as well when a patient has a unique
request and a device has to be highly customized. Although time consuming,
these projects can lead to discoveries and help progress our understanding
about biomechanical principles.

Harvey has adapted prostheses to allow patients to resume participating
in sports. For several bilateral transfemoral amputees who were bicyclists, the
addition of a flexion stop just shy of 90· enabled them to fluidly pedal
a bicycle.

“Snowboarding has been one of my passions and something for which I
have also spent a great deal of effort in creativity,” Harvey said.
“This season, I arrived at designs for a bilateral hip disarticulation and
bilateral transfemoral to snowboard, keeping in mind low center of gravity and
versatility around the lift line.”

Technological advancements

In the past 2 decades, advancements in materials, techniques and
technologies, including electronics and microprocessors, have significantly
improved prosthetic design and components, offering prosthetists and patients a
variety of options. At the same time, such advancements have served in some
ways to increase the level of complexity and difficulty for prosthetists.

“Advancements in technology in both upper extremity and lower
extremity allow us to do more for patients,” Miguelez said. “It also
puts more pressure on practitioners to understand all of the different
technologies that are available, and then once they understand all the options,
to be able to decide which is the most appropriate based on the patient’s

For instance, to determine what electric terminal device may be the most
appropriate for a patient, the prosthetist must first understand the
capabilities of all the terminal devices that are available, as well as the
pros and cons of each hand in order to recommend the best component. The
prosthetist also must consider the technology as it relates to socket design
and socket materials and then understand how different materials will react
with the patient’s limb presentation.

It may be difficult to discern the complexity of an amputee’s care on an initial evaluation, according to Zach Harvey.
It may be difficult to discern
the complexity of an amputee’s care on an initial evaluation, according to
Zach Harvey.
Image: Morenatti E.

“One of our responsibilities is to keep our patients apprised of
new developments, and that is always a little challenging.” Miguelez said.
“Sometimes the hype of new technology does not necessarily match the
reality of new technology, so we have to manage patients’ expectations at
the same time that we are all continuing to learn,” Miguelez said.

While Lalla noted that the prosthetist’s job is to understand the
technology in order to use it to its full potential, but the prosthetist also
must ensure that the complexity ultimately is not passed on to the patient.

“Our philosophy is to educate ourselves well enough that we are not
letting technology that can achieve a better outcome hold us back due to it
being complex,” Lalla said. “We strive to make things as functional
as possible while still trying to keep it relatively simple in the form of

In addition, the prosthetist must be able to understand how to program
the prosthesis to achieve an optimal outcome.

John Miguelez works with Merlyna Adams, a quadruple amputee.
John Miguelez works with Merlyna
Adams, a quadruple amputee.
Image: Morenatti E.

“It is not as simple as pulling it out of a box and turning a
couple of dials and having it work. You can take the most advanced piece of
technology and put it on somebody and if it is not adjusted properly, it
certainly is not achieving the best outcome,” Lalla said. “You
certainly see cases where patients are fit with very technologically advanced
products that have not been optimized due to lack of experience on the
prosthetist’s part.”

At the same time, Lalla cautions that prosthetists should not overlook
less complex options. In some instances, simpler prosthetic options or systems
may yield a better outcome than a technologically advanced option.

“If you are dealing with somebody who is a bilateral or maybe if
age, strength or balance is a factor, those considerations might make things
complex,” Lalla said. “Going with a very simple lanyard type of
suspension can sometimes yield better results. The nice thing about that
lanyard system is you can don it sitting down, so it is simple, and I would
venture to say it is almost old technology but still has current

Looking to the future

While Harvey agrees that technology has progressed steadily, he believes
that progress has advanced far too slowly in the past decade. He noted that
many historic developments, such as sweaty gel liners, socks to manage volume
and the same old socket materials we’ve been using for the last 20 years
are highly pervasive in the state-of-the-art prosthetic limb.

Ertl Procedure Presents Socket Fitting Challenge

The Ertl procedure, developed after World War I by Janos Ertl,
Sr, MD, addresses treatment of the skin, muscles, nerves and bone in below knee
amputations and often results in a pain-free residual limb. Today this
procedure is also performed for above-knee amputations as well.

The procedure is not without fitting issues, however. A
patient with an osteomyoplastic reconstruction or an Ertl procedure has to be
fit with a different style socket than practitioners may have been taught in
school, noted Scott Sabolich, CP, LP, owner and clinical director of Scott
Sabolich Prosthetics & Research.

“It requires a socket that has distal weight bearing,
where most of the time in the last 50 years of prosthetics, we’ve never
wanted distal weight bearing. It changes the whole dynamics of the fit and it
makes it much more difficult to fit someone when they have to put weight on the
end of their residual limb. It decreases stability, it increases a lot of the
problems in fitting the brim, and if you don’t know what you’re doing
it takes a lot more effort.”

The procedure is generally performed on young, healthy
patients who have experienced significant trauma to their limb. Patients with
war injuries are the most appropriate candidates for the procedure, which
explains why its use increases during wartime and lessens during peacetime.

“Dr. [William] Ertl is here in Oklahoma. We see a lot
of his cases. He’s very successful; in fact, he brags about a 97% success
rate of all of his surgeries, which is quite high compared to the typical
below-knee amputation,” Sabolich said. He said Janos Ertl believed that
the surgeon’s job is to ensure the amputee is left with a living, growing,
weight-bearable residual limb, not simply to pass the responsibility of limb
health and utility on to the prosthetist.

“We’re seeing a lot more of the military
orthopedic surgeons jumping on board and doing a lot more Ertl reconstructions
in Walter Reed and Brooks Army because the younger soldiers don’t have any
health complications. They can heal from an invasive surgery like that where
you’re actually connecting the bones together. We’re seeing a lot
more of that involved but a lot of prosthetists out there have no idea how to
fit these things. It is just a completely different way of building a
socket.” — Mary L. Jerrell, ELS


“Admittedly, we have many more options of interface material,
suspension mechanisms, component design and cosmetic restoration than ever
before. New microprocessor knees, ankles and hands now move more similarly to
their anatomical counterparts,” Harvey said. “The progress I have
seen is painstakingly slow, with very few breakthrough inventions having
occurred during my career.”

However, Harvey acknowledged that this slow progress is what pushes the
boundaries and improves prognoses. He noted that an increasing number of
wounded warriors have returned to active duty, including combat-related
positions, due to great prosthetic fit, function and training.

“When we pay attention to detail, learning from mistakes, it is
possible to achieve tremendous outcomes with the current technology. The
evolution of socket design is a great example of how we continue to build upon
biomechanical and prosthetic principles to create better fitting and better
aligned prostheses,” Harvey said. “I look forward to progression of
powered prosthetic designs as well as more commonly performed surgical
techniques such as osseointegration, targeted muscle reinnervation, limb
regeneration and composite tissue allografts to improve outcomes within the
near and distant future.” — by Mary L. Jerrell, ELS

Disclosure:Sources for this article
had no financial disclosures. The views expressed in this article are those of
the authors and do not necessarily reflect the offcial policy or position of
the Department of the Navy, Department of the Army, Department of Defense, nor
the US government.

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