CPO Materials Science & Technology Flashcards

Which lamination resin type is most commonly used in structural prosthetic sockets due to its balance of strength, weight, and ease of fabrication?

Answer: Acrylic (PMMA) resin

Acrylic (PMMA) resin is the most widely used lamination resin in prosthetics because it offers excellent strength, good workability, and proven clinical durability.

Polypropylene is preferred over polyethylene for definitive AFO fabrication primarily because it offers:

Answer: Higher stiffness and better memory retention under cyclic loading

Polypropylene provides greater stiffness and superior elastic memory compared to polyethylene, maintaining its shape better under the repetitive loads of ambulation.

In prosthetic socket fabrication, what is the purpose of using a 'check socket' (diagnostic socket)?

Answer: To verify fit, alignment, and comfort before fabricating the definitive socket

A check (diagnostic) socket made from clear thermoplastic allows the prosthetist to verify fit, alignment, and pressure distribution before committing to the final definitive socket.

Which characteristic of titanium makes it an excellent choice for endoskeletal pylon components in active prosthetic users?

Answer: Higher strength-to-weight ratio combined with excellent corrosion resistance

Titanium offers an excellent strength-to-weight ratio and outstanding corrosion resistance, making it ideal for high-activity users exposed to varied environments.

A prosthetist notes that a patient's silicone liner is showing signs of delamination at the proximal trim line. What is the most likely cause?

Answer: Improper donning technique causing shear stress at the proximal edge

Repeated shear stress from improper donning — particularly rolling the liner while gripping the proximal edge — causes delamination of the fabric backing from the silicone at the trim line.

What is the functional purpose of a 'PETG' (glycol-modified polyethylene terephthalate) check socket compared to traditional polyethylene check sockets?

Answer: Greater clarity and lower forming temperature enabling easier fabrication and visual assessment

PETG offers excellent optical clarity and a lower vacuum-forming temperature than conventional polyethylene, making it easier to fabricate clear check sockets that allow visual skin assessment.