Plastics in Lower-Limb Orthotics

Plastics in Lower-Limb Orthotics

Our October 1976 Issue of the Newsletter discussed "Plastics in Lower-Limb Orthotics" and requested information from our readers as to their experiences and preferences. The following is the results of the questionnaire on this subject.

Fig. 1: Fitting the Molded Plastic AFO.

Results of the Questionnaire and a Discussion of the Results

1. Does your clinic use custom made orthoses formed from sheet thermoplastic material?

   YES - 71
   NO - 2

   One of the respondents who answered "NO" is an institution that treats only amputees. The other "NO" came from an orthotics facility in New England who gave as the reason "We use Ortholene blanks and laminated AFO's."

2. If the answer is "Yes" please name the materials used and show opposite the types of appliances made from the particular material.

   The responses to this question are shown in this Table.

1. Do you use preformed "off-the-shelf" AFO's?

   Thirty-one used preformed or "off-the-shelf" AFO's. Thirty-six who also used molded AFO's did not use "off-the-shelf" AFO's. Most of the respondents who used the preformed AFO's stipulated that the use was limited to initial trials or to those relatively few patients that could be fitted adequately. Those that refused to use the preformed unit felt that the better results obtained by custom molding was worth any extra effort necessary.

2. Please give the reasons for the answer you gave to question "3".

   Some typical responses were:

   "They (preformed) will work on some patients....."

   "Use (preformed) on easy to fit patients or those not needing the extra support."

   "If the doctor specifically prescribes (preformed), or if the patient insists after explaining the advantages and disadvantages."

   "I use preformed AFO's for pes equinus only. I use custom made for all other orthotic treatment."

   "Because (preformed are) no good; have to reheat and mold to have work properly, so may as well start from scratch and make your own."

   "Fitting difficulties - sizes do not fit many patients who are edematous, atrophied, or need support."

   "They don't fit."

   "Doctors prefer custom-made."

3. If you provide molded plastic orthoses, what type of equipment do you use in fabrication?

   The answers given were not always clear but it appears that:

   35 used a vacuum machine of one type or another
   19 used hand drape with vacuum
   14 used hand drape without vacuum
   8 used central fabrication

   Some facilities used more than one method, thus accounting for a total greater than the number of respondents that use custom formed orthoses. About the only conclusion that can be drawn from these figures is that vacuum machines are probably worth the investment.

4. Please give your opinions about the usefulness of sheet thermoplastics in orthotics.

   Nearly every respondent answered this question in some detail. Most cited lightness and cosmetic benefits.

   Some typical comments:

   "We feel that this is the biggest advance in orthotics in the last few years, providing the patient with a lightweight, hygienic, orthotic system."

   "We feel that molded AFO's are far superior to conventional braces in every respect. Most of our orthoses are constructed using the materials and the patients and their physicians are most pleased."

   "I am able to obtain excellent fit and control with plastics that would not be possible with a leather-metal orthosis. Also, it is lighter and more cosmetic."

   "We find it has great adaptations to orthotics, with unlimited applications."

   "It's the only way."

   "These orthoses are useful for cosmesis, function, and light weight."

   "Unlimited potential, but discretion advised."

   "I feel we have uncovered a new dimension to orthotics and look forward to further developments in the future."

   "Enables orthotists to apply new ideas toward orthotics."

5. Have you experienced problems with the quality of the sheet plastic material? If the answer is "Yes", please explain.

   Twenty five respondents indicated that they had experienced problems with the quality of sheet plastic, while 32 said that they have had no problems.

   Alan Finnieston of Miami, Florida, who has had a lot of experience in the use of the sheet plastics offers the following observations:

   "In answer to your question #7, we have had many difficulties with the quality of thermoplastic sheet material of various types. For example: Polypropylene, polyethylene, ABS, styrene, and polycarbonate to only mention a few. We have been involved with thermoplastics and the vacuum-forming field for approximately ten years.

   Orthotics and prosthetics cannot justify, by virtue of their volume, specific formulations of material to specifications. As an example, most Orthotists or Prosthetists are buying polypropylene on a local level through a distributor. The distributor has no means of controlling what material or formulation of polypropylene he is receiving. Polypropylene is available in homopolymer, copolymer, random or block, plus many variations of grades; extrusion, injection and film, with a multitude of modifiers which can vary specifications of the base material. One then must seek out the reputable extruder with high-quality equipment and technology. This eliminates the problem of the re-ground materials of unknown formulations plus regulation of the extrusion prices."

6. Are special courses needed to provide orthotists and other members of the clinic team with training in the prescription, fabrication and fitting of molded plastic lower-limb orthoses? Please explain.

   Of the 73 respondents, only 2 said that they felt that special courses for orthotists and other members of the clinic team were not needed. One of these provided only "hard corsets" and "arch supports"; the other stated "No, not in lower limb orthotics, because the basic rationale is unchanged as is the function." An institution that provided only "hand splints" said "Registered occupational therapists who are trained in splinting in their academic and clinical education fabricate all splints in the clinic." One clinic and one orthotics facility both of which provided molded AFO's answered with a question mark, and another clinic did not respond to this question.

   However, the remaining 67 respondents felt quite strongly that special courses are needed if orthotists and other members of the clinic team are to make maximum use of the advantages afforded by sheet thermoplastics. The vast majority felt that all members of the clinic team should be offered training, but a few felt that formal training should be restricted to orthotists.

   Some of the responses are:

   "Yes, any further education is valuable to the entire team."

   "Yes - exchange of ideas would be very useful particularly concerning fabrication. I have been making vacuum formed molded orthoses for 2-1/2 years and I still find it useful to exchange ideas with others who do it; to get the bugs out."

   "Yes. It would be most help to attend a course in KAFO's."

   "Definitely. Many problems can be circumvented with previous training."

   "Yes, I believe this would be very helpful. I think this could be done in the curriculum of the schools already teaching Orthotics and Prosthetics. Seminars are helpful but only touch upon the surface. I think this area has already been covered in the last 5 years and needs more advance hands-on courses and experiences by physicians, therapists, orthotists and prosthetists."

   "Yes. So many doctors still want to use old methods."

   "Orthotists only should have courses, and then show the latest uses and methods. I feel that he should be the one to explain the advantages to the other team members."

   "I think courses stressing cast modification, preparation, hand layup, and fitting problems would be helpful to the whole team. Personally, I have seen all the vacuum layup films I can stand."

Overall Conclusions

Thus, it seems obvious that sheet thermoplastics have a great potential in all aspects of orthotics and that appropriate education programs are needed and wanted.

Alan Finnieston included in his reply an announcement that his firm intends to offer "a series of instructional programs on the correct use of plastics in contemporary orthotic practice" and suggests that those interested in attending contact him at 1901 N.W. 17th Avenue, Miami, Fla. 33125.

The results of this survey have been forwarded to the formal education programs in this country and abroad with the hope that the faculties will be stimulated to initiate programs in this area.