polyethylene VS polypropylene
Hoag, Lance
Description
Collection
Title:
polyethylene VS polypropylene
Creator:
Hoag, Lance
Date:
10/15/2002
Text:
I am looking for documented explanations from highly regarded sources
within the industry of the capabilities and limitations of polypropylene vs.
polyethylene with regard to durability, especially regarding the specific
AFO designs and their inherent problems describe below.
I am writing in search of advice regarding AFO designs and materials.
Currently I receive a lot of orders for a very specific design of total
contact AFO which is best described as a cross between the Orthomerica
TC2/Cascade DAFO designs and a fracture AFO. Specifically, this design
extends to the tibial crest, running the entire length of the tibia, as well
as, over the dorsum of the mid-foot. In order that the AFO's anterior
section may be laid open for donning, the physician's order specifies thin
polyethylene. Understandably, the resulting problem is that the plastic
tears at the highly stressed malleolar area with repeated resistance of
plantarflexion. This material failure is even more problematic when
combined with the Tamaracks and posterior stops used with the articulated
AFO orders (the plastic tears and rips the plastic at the screw hole for the
joint).
I have recommended using polypropylene pulled thinly over the anterior and
dorsum, similar to the TC2 or the DAFO. However, fabrication is finding it
difficult to get a pull than is consistently thin enough to satisfy the
expectations of flexibility of the anterior/dorsal sections. My wish-list
would consist of documented explanations from highly regarded sources within
the industry of the capabilities and limitations of polypropylene vs.
polyethylene with regard to durability (i.e. why polyethylene may not be
the most appropriate material choice with regard to the described AFO
designs). In addition, any tech tips that can increase consistency for
fabrication would be appreciated.
Assuming that volumes of supporting testimony and evidence are ineffective
in swaying physician favor away from the less-than-durable polyethylene, my
wish-list would include proven modifications in the design or fabrication
that would increase the durability of the polyethylene and prevent the
tearing at the Tamarack joint holes.
I appreciate your time, considerations and thoughts.
Lance Hoag, C.O.
Director of Orthotics
Shriners Hospital
Center for Orthotic & Prosthetic Care
within the industry of the capabilities and limitations of polypropylene vs.
polyethylene with regard to durability, especially regarding the specific
AFO designs and their inherent problems describe below.
I am writing in search of advice regarding AFO designs and materials.
Currently I receive a lot of orders for a very specific design of total
contact AFO which is best described as a cross between the Orthomerica
TC2/Cascade DAFO designs and a fracture AFO. Specifically, this design
extends to the tibial crest, running the entire length of the tibia, as well
as, over the dorsum of the mid-foot. In order that the AFO's anterior
section may be laid open for donning, the physician's order specifies thin
polyethylene. Understandably, the resulting problem is that the plastic
tears at the highly stressed malleolar area with repeated resistance of
plantarflexion. This material failure is even more problematic when
combined with the Tamaracks and posterior stops used with the articulated
AFO orders (the plastic tears and rips the plastic at the screw hole for the
joint).
I have recommended using polypropylene pulled thinly over the anterior and
dorsum, similar to the TC2 or the DAFO. However, fabrication is finding it
difficult to get a pull than is consistently thin enough to satisfy the
expectations of flexibility of the anterior/dorsal sections. My wish-list
would consist of documented explanations from highly regarded sources within
the industry of the capabilities and limitations of polypropylene vs.
polyethylene with regard to durability (i.e. why polyethylene may not be
the most appropriate material choice with regard to the described AFO
designs). In addition, any tech tips that can increase consistency for
fabrication would be appreciated.
Assuming that volumes of supporting testimony and evidence are ineffective
in swaying physician favor away from the less-than-durable polyethylene, my
wish-list would include proven modifications in the design or fabrication
that would increase the durability of the polyethylene and prevent the
tearing at the Tamarack joint holes.
I appreciate your time, considerations and thoughts.
Lance Hoag, C.O.
Director of Orthotics
Shriners Hospital
Center for Orthotic & Prosthetic Care
Citation
Hoag, Lance, “polyethylene VS polypropylene,” Digital Resource Foundation for Orthotics and Prosthetics, accessed November 7, 2024, https://library.drfop.org/items/show/219868.
