TTAS:
Obstacles to providing prosthetic service in the developing world are extensive. Limited
access to transportation, poor communication infrastructure, a lack of social services, and
inadequate education impede efforts to establish and maintain proper care centers.
Therefore, the facilities that are established to serve these regions are scarce, and not
within reach of those most in need. Moreover, they often have limited resources and can
only provide the most basic care.
One solution to this shortage has been the development of a thermoformed copolymer
prosthesis with an integrated socket and pylon, dubbed a “monolimb.” [ Insert picture of
monolimb] The goal of monolimb technology is to create practical, durable, costeffective prosthetic limb that is suitable for the economic limitations and geographic
environments of the developing world. To date, these limbs have been used successfully
in nations such as China, El Salvador, and Vietnam.
One limitation of this existing monolimb solution is the training required to manufacture
and fit each limbs. In order for prosthetic limbs to be effective, they must be properly
aligned. Alignment is the relative position and respective orientation of the prosthetic
socket and foot in 3-dimensional space. Prosthetic alignment determines the forces
applied to the residual limb and the motion of the body in gait and contributes
substantially to a patient’s acceptance of a limb.
Traditionally, alignment is performed by a trained prosthetist with a comprehensive
knowledge of gait dynamics, socket-tissue interface mechanics, and patient comfort. In
the developing world, training of this kind is often unavailable. The requirements for
established space, a properly trained clinical and support staff, and geographic location
with respect to the underserved population of amputees often limit the effectiveness of
large, permanent care facilities, especially in regions of political unrest, geographic
barriers, and/or economic hardship. It is often in these situations where this type of care is
most needed.
In response to these existing limitations, Prosthetics Research Study partnered with CIR
(Center for International Rehabilitation, Chicago IL) to develop an alignment
methodology and a corresponding inexpensive fabrication system which allow lesstrained technicians to manufacture properly-aligned monolimbs at a substantial reduction
in cost and capital requirements as compared to a conventional prosthetic care facility.
The PRS Transtibial Alignment System (TTAS) was developed in two forms: a standing
system ( Link to figure below) and a supine system ( Link to figure below). These
systems allow a technician to easily document and set the proper orientation of the
prosthetic components to match the normal position of the missing limb. A universal
casting fixture maintains the proper alignment of these components during monolimb
fabrication. Monolimb technology offers cost effective prosthetic limbs, but at the cost of
offering only a crude ability to alter alignment through foot rotation and heel lifts.
Therefore, it is vital that the proper alignment be obtained during the fabrication process.
Research is currently being directed toward the alignment of monolimbs fabricated from
both forms of the TTAS. A recent RPS pilot-study of eight subjects showed that
monolimbs produced by the TTAS were acceptable, but patients exhibited some signs of
mal-alignment ( Link to ISPO abstract). The systems are now being modified to
incorporate standard alignment settings to improve socket fit and function. Additionally,
a large-scale remote trial will be conducted in Q3 of 2004. Both forms of TTAS will be
sent to Thailand/Burma to create 200 monolimbs for patients in need. System redesign
and assessment of data collected during the trial will follow in late 2004.
CLEG:
Clinical Trial Evaluation:
The Microprocessor Control C Leg
Versus Traditional Non-microprocessor Transfemoral Prosthesis
Since the inception of energy storing foot technology, the prosthetics industry has not
seen as dramatic an improvement in component technology as the introduction of the C
leg. New knee technology such as the C Leg has been validated in recent investigations
throughout the industry. These studies have shown that with use of the C Leg there is a
significant improvement in gait, stamina and psycho-social well-being (Otto Bock, C Leg
Participant, 1997). However, this research has been limited in scope in that it has
included neither patient pre and post-C Leg activity levels nor patient well being in a real
world environment.
PRS is currently conducting a research study on the comparison of the C Leg to a
traditional, non-microprocessor (NMP) prosthesis at the time just before, during and after
a transition to a C Leg. The purpose of this research is to provide a comprehensive “real
world” view of the microprocessor technology currently available to users. In doing so,
we surmise that funding agencies will be better educated in the quantitative and
qualitative incentives for increasing access to these beneficial prosthetic technologies.
Currently, we are studying a population of 20 transfemoral (above the knee) amputees in
a range of ages and functional levels over two years. In this study, PRS will evaluate
each group to determine why people choose, continue to use and prefer one prosthesis
over another as well as to document the functional differences between the two systems.
This study will not only highlight the functional capabilities of the C Leg, it will also
highlight the strength of individual choice and preference through all activity levels. As
it is designed, the study outcomes will provide clinical data and performance
documentation illustrating the C Leg’s functionality in a real world setting.
Several activities have been determined in order to accomplish this:
 Conduct a clinical trial to emulate a real world situation where 20 patients transfer
from a non-microprocessor (NMP) prosthesis to an Otto Bock 3C100, (C Leg),
 Two unique participant groups; Geriatric (K-2) and Active (K-3-4) in order to
capture the different functionality benefits of using the C Leg system. For each
group in this multiphase study, we will collect objective gait and validated
preference & satisfaction data. In order to do this, several outcome measurement
tools are being used,
 In order to provide quantitative and qualitative data, we will use existing
scientifically validated measurement tools and tools developed specifically for this
research.
 Quantitative Tools:
o Amputee Mobility Predictor (AMP), Robert Gailey, PhD PT
o Divided Attention Task, “Walk & Talk”, PRS
o Stair Assessment Index (SAI), PRS
o Hill Assessment Index (HAI), PRS
o Obstacle Course, PRS
 Qualitative Tools:
o Prosthesis Evaluation Questionnaire (PEQ), PRS
 Addendum: Falls & Mental Energy, PRS
o Short Form 36 (SF 36), MOS
NOELLE’S PART OF C-LEG:
Stair Assessment Index (SAI)
The Stair Assessment Index (SAI) is a 14 level ordinal scale that assesses the functional
ability of transfemoral amputees for stair ascent and descent. It is being used in the C
Leg study as a physical measurement tool to document different gait styles on the stairs.
It was created to address the limitations of existing functional measures and is based on
common ascent and descent patterns and assistive device usage. The SAI was developed
because current measurement tools were not sensitive enough to determine differences in
gait styles from one prosthetic device to another. Measurement tools, such as the
Functional Independence Measure (FIM), assess disability on a continuum of dependence
and limited independence while the SAI assesses gait patterns reflecting the quality of
independence for stair ascent and descent. The SAI is not a validated tool as of yet, but
early results show enough sensitivity exists to determine technique differences in one
type of prosthetic knee to another in a functional evaluation, thus reflecting qualities of
independence.
Hill Assessment Index (HAI)
The Hill Assessment Index (HAI) is a 12 level ordinal scale developed to address
different characteristics of hill ascent and descent in preparation for the C Leg clinical
trial comparing different prosthetic knee units. The HAI assesses gait patterns on hills
combined with assistive device usage reflecting the quality of independence. Quality of
independence is important as multiple prosthetic knees allow the amputee different
features of stability and mobility for different levels of function on uneven terrain. The
HAI was developed out of a need to document the differences in function with different
knee units. This expanded independence scale allows documentation of outcomes which
are more comprehensive and accurate. The HAI is not a validated tool as of yet, but
initial results in the C Leg clinical trial show enough sensitivity exists to determine levels
of independence and usage of one prosthetic device as compared to another.
AAOP:
Special Demonstration Program Grant (AAOP)
Prosthetics Research Study is participating with the American Academy of Orthotists and
Prosthetists (AAOP) in Special Demonstration Program Grant from the Department of
Education.
The objective is to Advance Orthotic and Prosthetic Care through Research, Standards of
Practice and Outreach. Currently, PRS and the Academy are implementing the following
six projects to achieve the established objective:
1. National Awareness & Recruitment Campaign
GOAL: To increase the number of qualified students entering schools and pursuing
careers in O&P through an education and awareness program in technical and high
schools, including those individuals living with a disability by encouraging practitioner
mentors in partnership with leading disability organizations and a national mentoring
program.
2. Clinical Standards of Practice Consensus Conferences
GOAL: To host two new consensus conferences on the two highest priority topics
determined by Academy leadership, and to disseminate the findings of the consensus
conferences to practitioners, researchers and consumers by publishing and disseminating
the findings of those two conferences through an O&P journal and leading consumer
magazines.
3. Advanced Degree Conferences
GOAL: To foster advanced scientific and research education in O&P thus building the
academic and scientific research capacity of the profession by hosting two conferences to
analyze the current challenges that limit the prevalence of applied research,
simultaneously developing a strategic plan and a set of recommendations for universities
and educators to assist in addressing the need.
4. Master Agenda Conference
GOAL: To improve the consensus conference program, begun with pilot funds last year,
by hosting one conference that will develop a Master Agenda and structured plan for
future consensus conferences to be held over the next 15 years. The Master Agenda will
prioritize future O&P consensus conference topics, add consistency and structure to the
format of final documents and thus improve the knowledge base on clinical standards of
practice in O&P. This conference will also establish a recommended format for future
consensus conferences, based on the lessons learned from the first four consensus
conferences, and on recommendations from who are recognized experts in this process.
5. Geographic Map
GOAL: To identify provider shortage areas through a geographic area assessment and
report of O&P practitioners and services, and to encourage graduates and providers to
relocate and apply their skills to these at-risk populations by disseminating copies of the
report to students at the six accredited programs, the five technical colleges and to
retiring Academy members.
6. Online PCE Courses
GOAL: To further disseminate the findings and improve the quality of care by enhancing
professional education on standards of practice. To assure O&P consumers have access to
quality care by developing three new continuing education courses for the two completed
consensus conferences (Scoliosis and Post-Operative Management of the Lower
Extremity Amputee) and one of the two consensus conferences to be completed in this
project grant (Orthotic Treatment of Positional Plagiocephaly ).
WEBED:
Amputation Surgery Education
Amputation surgery, while performed quite frequently throughout the world, is highly variable in both
content and intensity. Patient outcomes are strongly dependent upon the expertise and experience of the
surgeon. Many amputations, however, are performed by surgeons with limited exposure and skill in this
specialty. Attention to small details, often overlooked, can make great strides toward a successful
rehabilitation and prosthetic fitting. Unfortunately, this information is uncommon and is spread across
multiple resources, if available at all.
Prosthetics Research Study is leading an effort to create a comprehensive, centralized educational program
for surgeons in the area of amputation surgery. This project, developed in collaboration with Otto Bock
(Minneapolis, MN) and the Amputee Coalition of America (ACA) will provide free material via the worldwide-web. The goal is to improve patient outcomes by providing an easily-accessible center for surgeons
to locate information, review recent advancements, and re-familiarize themselves with the critical aspects
of amputation surgery.
The goal of the Amputation Surgery Education project is to create a web-based educational program.
Toward this end, we are collecting multimedia materials to support this effort and provide a comprehensive
array of educational tools. These will include photos, videos, documents, recent literature, publications,
and a variety of other helpful materials. These materials will be organized into “teaching modules” for
each major level of amputation.
The Amputation Surgery Education website will be officially launched in Q4 of 2004.
HARMONY:
VASS Harmony: Socket Suspension
Currently, PRS is performing early investigational research into the new vacuum assisted
suspension technology for transtibial amputees. The most widely used version of vacuum
assisted suspension system is known as the VASS Harmony System, sold by Otto Bock..
Harmony has been in clinical use since 1996, but there has been a recent increase in its
use.
Comments in the clinical environment have been very positive and very intriguing.
Statements and observations about the system include: the system reduces distal end
edema, stabilizes residual limb volume, increases circulation and actually heals wounds
on the residuum. However, these statements have not yet been substantiated through
objective and independent investigation.
The current research being conducted is done solely through the volunteership of our
local community amputees and practitioners. The first phase of the research effort was
concluded in February. This arm of our research included two multi-day technical
sessions with the inventor of the Harmony system. Each session was planned in order to
bring together the manufacturer representatives and five Seattle area practitioners
partnering with PRS, interested in learning the philosophy behind the VASS Harmony
system, and the clinical techniques to fit and optimize this system..
The second phase of this research effort is a comprehensive investigational survey:
“Interview and Survey of persons who have experienced the Vacuum Assisted Prosthetic
Socket Suspension System, VASS Harmony.” The purpose of our research is to survey
people who have experienced the Harmony system to quantify what the user sees as
beneficial and challenging about this socket technology. These efforts include a “onetime” oral interview, and administration of our prosthesis evaluation questionnaire
(PEQ).
Funding for this project has been provided by the system’s manufacturer, Otto Bock
North America.
If you are interested in participating in this research please contact Kate Allyn for more
information at: 206-903-8136, Email: Kate@prs-research.org
(Due to the nature of email transmissions, your privacy and anonymity can not be
guaranteed.)