L20 WillowWood Flashcards
R&D Team
- Develop products (9 products in last 2.5 years)
- Introduce outside funding opportunities (DoD, NIH, VA…)
- Currently have $14M in funding from DoD and NIDILRR
- Conduct research on products and disseminate research results to O&P
community - Explore market opportunities and current development trends
- Identify and manage outside partnerships/collaborations
- Support IP portfolio
What is a Prosthesis?
- Prosthetics replace the function and appearance of a missing limb
- If a physician decides that the patient is a candidate for a prosthesis, then the physician writes a prescription
- The patient then takes the prescription to a prosthetist
Prosthetist
A prosthetist is the person who selects, fits, and adjusts the prosthesis
- Prosthetists are WillowWood’s customers
- Most Prosthetists are certified by the American Board for Certification (ABC)
- Understanding biomechanics is critical to success of
these devices - Socket/Socket Interface
- Knee
- Foot
Rehabilitation
- The aim of the rehabilitation is to aid the amputee to gain independence at the highest level they can
- Very much a team approach
- Physician/surgeon
- Prosthetist
- PT
- OT
- Psychologist
- Family
Paying for a Prosthesis
- Most lower-limb prostheses in the US are paid for by Medicare
- When billing Medicare, a prosthetist must classify the components of the prosthesis according to standard billing codes known as “L-codes”
- The codes are written to describe a certain type of function or material; some mention products by name
- CMS determines how much money is reimbursed for each of the codes in each region of the country
- If a product is not adequately described by any of the existing codes, it must be billed under a “miscellaneous” code
- When we introduce a new product, we must either make sure that it fits an existing code, or apply for a new code
- Sales history required when applying for a new code
- The types of feet, ankles, and knees that Medicare will reimburse for each patient are dictated by the expected functional level for that patient
Functional Levels
- Level 1: The amputee can only walk on level surfaces, and only at one cadence
- Level 2: The amputee can only walk at one cadence,
but can traverse uneven surfaces - Level 3: The amputee can only walk with a variable cadence and can traverse most environmental barriers
- Level 4: Exceeds basic ambulation skills; high impact, stress, or energy levels
Prosthetic Components
- Interface
- Socket
- Suspension (Pin-locking, Suction, Elevated Vacuum)
- Distal Components (Foot, knee, ankle, pylon, adapters)
Prosthetic Liner
Often some type of interface is worn between the
socket and the residual limb
* Sock
* Foam
* Gel Liner
Goal of the interface
* Increased comfort
* Protection from forces applied to the limb
* Help adjust to volume changes during the day
We offer:
* TPE
* Silicon
* SmartTemp
Prosthetic Liner cont.
Biomechanics come into play with material selection and design
* Gel used
* Gel profile
* Fabric
* Panels
- Great for mechanical comfort, poor for thermal comfort
Interface Accessories
- Knitted socks
- Gel Cups
- Foam Pads
- Volume Management Pads
Prosthetic Socket
Custom-made structure that fits onto the residual
limb
There are different methods of designing sockets
- Example: different methods for bearing the
patient’s weight
A good fit is crucial; otherwise, problems such as
pistoning (excessive vertical movement) occur
- Challenges: Limb volume change
Prosthetic Socket – Shape Capture
- Make a cast (negative model) of the limb
- Fill cast with plaster to create a positive model
- Modify the positive model
Prosthetic Socket – CAD
- Scan the shape of the limb
- Digitally modify the shape
- Carve a positive model from foam
Prosthetic Socket - Fabrication
From the positive model, a socket is fabricated, using one of two methods:
- Thermoplastic
- Laminated
Check Socket
Thermoplastic check socket typically made using a blister forming technique
Used to ensure fit
* Static
* Dynamic
Definitive Sockets
- If fit is ok, prosthetist will fabricate definitive carbon
fiber socket - A liquid plastic is used to saturate layers of textiles that have been applied over the
positive model - The plastic bonds the fabric layers together, creating a lamination
- Advantage: the prosthetist/ technician has a great deal
of control over the strength, stiffness, & thickness of the socket - Disadvantage: not possible to change the shape of the
finished socket to adjust the fit
Socket Suspension
- Suspension is responsible for keeping the prosthetic limb on the amputated limb
Types of Suspension
- Locking
- Suction
- Elevated Vacuum
Prosthetic Feet
- Specific to activity level
- Available in a range of sizes, toe stiffnesses, and heel heights
Alignment of the Prosthesis
- Next, the prosthesis is assembled & the alignment
process begins - “Alignment” = positioning the socket with respect
to the foot (and knee) so that the patient walks with a normal gait and does not experience any undesirable force applied on the residual limb - The prosthetist adjusts height, slide, angle, and
rotation
Alignment Steps
Bench alignment: the prosthetist aligns the components in a basic
alignment in accordance with the characteristics of the components & with standard prosthetic technique
- Static alignment: the amputee dons (puts on) the prosthesis, and the prosthetist makes some initial adjustments while the amputee is standing still
- Dynamic alignment: the amputee walks on the prosthesis, usually within a set of parallel bars
- Prosthetist observes amputee’s gait & asks how the prosthesis feels
- Prosthetist adjusts the alignment, the amputee walks again, & the process is repeated as much as necessary
Upper Extremity Prostheses
Body-powered
Myoelectric
-Surface (commercial) or implanted (research)
