Front Matter

274 Canine Sports Medicine and Rehabilitation

Computer‐aided design
and manufacturing

Biomechanically appropriate design is needed
to apply these mechanical control systems.
The field of orthotics and prosthetics has its
roots in the artisan craftsman, such as black­
smiths, woodworkers, and leather trades.
Computer‐aided drawing and 3‐D designing
is bringing the level of accuracy out of an art
form into the realm of mechanical precision.
With the advances in CAD software and mod­
ern manufacturing techniques, V‐OP device
fabrication has taken a  significant step for­
ward in integrating the aforementioned
mechanical principles. The advantages of
CAD in H‐OP and now V‐OP fabrication
include design repeatability, consistent and
intentional biomechanical force application,
and speed in manufacturing. Sophisticated
manu facturing technologies include handheld
3‐D scanners that capture limb topography for
digital sculpting, multiaxis carver machines to
rapidly and accurately produce complex
orthosis and prosthesis‐positive models, and
complete systems integration utilizing medi­
cal‐grade 3‐D printing (Fairley, 2013).

Is there a place for 3‐D printing?

Fabrication of a hard‐shell device can be
accomplished by vacuum molding or 3‐D
printing. Traditionally H‐OP and V‐OP
devices have been manufactured using the
former. As a rapidly developing technology,
3‐D printing brings innovation and interest
for its potential use in V‐OP. Importantly, a
thorough understanding of quadrupedal bio­
mechanics and the V‐OP manufacturing pro­
cess is required before delving into 3‐D
printing of V‐OP devices. The goal of V‐OP is
to create a comfortable, well‐fitting, biome­
chanically appropriate, and functional thera­
peutic device. Strict adherence to the principle

that an animal patient must be evaluated and

diagnosed is necessary for success. It is the

view of the authors that these devices should

be  prescribed by a veterinarian as a durable

medical device specifically indicated to treat

a diagnosed pathology. A universal tenet of

veterinary practice acts is that diagnosis and

treatment of animal patients is the exclusive

purview of licensed veterinarians. A V‐OP

solution has the potential to create therapeu­

tic outcomes for a patient, but it has the

potential to cause harm as well. Therefore, the

application of such devices should be man­

aged by a referring veterinarian, and ideally

one who has gained a level of knowledge and

experience in V‐OP.

The manufacturing of a V‐OP solution

requires an understanding of anatomy, kine­

matics, kinetics, and biomechanics. At its

core, the only role vacuum molding and 3‐D

printing serves is the actual manufacturing of

a part or object. The design software and

shape creation is separate from molding

or  printing of the device. Simply being able

to  manufacture a device is not enough to

meet therapeutic goals. A close relationship

between the prescribing veterinarian and a

knowledgeable manufacturer provides the

ideal framework for successful V‐OP applica­

tion regardless of the actual method of

fabrication.

Materials

The material selected to fabricate a V‐OP

solution must meet or exceed the mechanical

properties of the currently preferred materi­

als polypropylene and laminated carbon

fiber. Polypropylene is extruded in sheets

creating a strength and molecular alignment

superior to 3‐D printing raw materials (Wong

& Hernandez, 2012; Wu et  al., 2015). Carbon

fiber lamination exceeds all other materials

for the ability to create complex shapes with

Take home points: (1) Digital amputation is not

always a benign procedure. Secondary complica­

tions can be severe and lifestyle altering. (2) Although

pathology may affect only the digits, an orthosis may

require a proximal component for suspension; device

design should minimally alter ROM and function of

the proximal segments (e.g., low durometer hinges).

(3) Thorough evaluation of all limbs is important to

prevent over‐ and underdiagnosing concomitant

pathology.