Prosthetics

Overview

 
  • The earliest evidence of an amputee is a 45,000-year-old human skull in the Smithsonian Institute that has teeth shaped and aligned in such a way to indicate he was an upper extremity amputee
  • The prostheses of the ancient 

    • cultures began as simple crutches or wooden and leather cups. This evolved into a type of modified crutch or peg to free the hands for everyday functions. An open socket peg leg held cloth rags to soften the distal tibia and fibula and allow a wide range of motion.
    With the birth of the great civilizations of Egypt, Greece and Rome came the development of the scientific approach toward medicine and subsequently prosthetic science. Pliny the Elder wrote of Marcus Sergius, a Roman general who sustained injuries and a right arm amputation during the second Punic war (218 and 210 BC). An iron hand was fashioned to hold his shield, and he returned to battle. 
    The Dark Ages was a time in which there was little scientific illumination. There were not very many prosthetic alternatives available to the amputee except basic peg legs and hand hooks, which only the rich could afford. Knights had cumbersome prostheses made by their armorers for use in battle, but they were more cosmetic than functional. 
    The Renaissance signaled a rebirth of science and a rediscovery of medical practices originated by the Greeks and Romans. French army barber-surgeon Ambroise Pare invented upper and lower extremity prostheses that show knowledge of basic prosthetic function. 
  • From the 1600s to the early 18 00s, 

    • we see great refinements of the prosthetic and surgical principles put forth. The invention of the tourniquet, anesthesia, analeptics, blood clotting styptics, and disease-fighting drugs brought medicine to the era, and also made amputation an accepted curative measure. The surgeon had time to make residual limbs more functional, thus allowing the prosthetist to make better prostheses. 
    In 1696, Pieter Verduyn, a Dutch surgeon, introduced the first non-locking, below knee prosthesis, which bears a striking similarity to today's joint and corset prothesis with its external hinges and leather thigh lacer to bear weight.ADD JPEG 4
    In 1858 Dr. Douglas Bly invented and patented Doctor Bly's anatomical leg. He called it "the most complete and successful invention ever attained in artificial limbs." Later in that century, Dubois Parmlee invented an advanced prosthesis which had a suction socket, polycentric knee, and multiarticulated foot; Gustav Hermann suggested using aluminum instead of steel; and Heather Bigg wrote a textbook detailing placement of joints for correct alignment. 
    As WWI began, the Surgeon General of the U.S.Army recognized the disturbing lack of care for amputees in America. He invited prosthetists to Washington, DC to discuss technology and its development. From this meeting arose the present day American Prosthetics and Orthotics Association. 
    This development contributed more to the science of prosthetics than any other occurrence in history. Through this forum prosthetists could develop ethical standards, scientific and educational programs, and build better relationships with other health professionals. 
    This, in turn, has led to quantum leaps in technology: the SACH foot, the Mauch S-N-S system, myoelectric arms, the C-Leg™ and Flex-Foot™, just to name a few. 

 

 
 

Hrastovlje, Church of the Holy Trinity, Slovenia


Peg leg on wall painting (click for VR panorama)

Peg legs and bionic limbs: the devlopment of lower extremity prosthetics. Gutfleisch O (2003) Interdisc. Sci. Rev. 28(2):139-148.

Palmer's Artifical Leg


American innovation at the first ever World's Fair at the Crystal Palace in London, 1851
 

Orthotics

Functional Foot Orthoses

People have been wearing shoes since the dawn of time to make life’s hard road more bearable. Early shoe designs dating back thousands of years suggest that appearance has always been as important as comfort--if not more important. The shoe was a status symbol.

As shoes became more accessible to the general population, people demanded better comfort. At this time shoes were made the same. There was no such thing as a left or right shoe (a concept that would not catch on until the 1800s.) Early innkeepers recognized that most weary travelers complained of foot pain. The first insoles were made by innkeepers from matted animal hair retrieved from the local barn (later called felt).

Over time, shoe makers, or cobblers, modified the innkeepers’ foot pads and began to add leather materials to the insides of shoes to create a better, more comfortable fit--the first arch supports were born. Early arch supports were made by laminating layers of leather strips together, molding them to shoe lasts, and then shaping the arch support by hand for wearing inside shoes. These new arch supports helped create a new level of comfort for people wearing shoes. The only problem was that arch supports were often bulky and heavy.

By the early 1900’s electricity and bench grinders made cutting down leather laminated devices much faster and therefore more affordable for the general population. In addition, lighter and softer materials were combined with leather blanks to create an additional level of comfort.

The next major enhancement came in the 1960s when a new generation of thermoplastics was introduced to the marketplace. Thermoplastics mold to a form, such as a replica of your foot, when hot. Once cooled, the material retains the molded shape of the form. Thermoplastics, such as polypropylene, are lightweight especially in comparison to leather and foam materials. More importantly, thermoplastics provide a strong, durable, and thin orthotic that can support the foot and body while fitting into modern style shoes. As a further plus, polypropylene is recyclable.

The introduction of thermoplastic materials led to new theories about how to make arch supports. Instead of using a shoe last to make the device, medical professionals began using a mold or cast of a person’s foot, thereby creating a true orthotic. The medical definition of an orthotic is a brace that supports a specific body structure. More importantly, scientific principles were (and continue to be) applied to the foot’s structure and to foot orthotics to develop foot supports that can actually control the function of feet, legs, hips, back, and neck.

Since the 1960’s, the art of custom orthotic making has been continually enhanced so that today it is possible to build an orthotic that can help correct the foot deformities (such as bunions, flat feet, etc.) that cause typical aches and pains in the feet, legs, hips, back, and neck--the types of aches and pains people in all cultures and all parts of world experience. The custom orthotic is typically prescribed by a licensed Foot Care Professional who is Medically trained. Orthotics are fabricated by Professional Orthotic Laboratories.

Records from the United States patent office use many different names to describe those inventions intended to improve foot and or arch function the "Orthotic". Detailed review of over 70 different registered inventions describes only two basic design techniques for orthotics. One technique builds a device by placing mass or substance in the arches of the foot; the other fabricates a plate-contoured to the plantar surface of the foot.

Many orthotic devices currently used today and first presented almost 100 years earlier strategically place mass so as to generate support to the medial longitudinal, lateral longitudinal and transverse metatarsal arches. Earlier orthotic inventions used the patients foot, then individual foot impressions and later shoe size formulas to generate the design of their arch supporting orthotic devices. Foot and or arch supports (orthotics) constructed in this fashion were recorded in both early and more recent patent literature.

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Other inventions describe fabrication of a plate contoured to the plantar surface of the foot, using milling and bending techniques to contour the material to foot impressions or scanned coordinates. This contoured plate was further stabilized with a heel post designed to control the position of the plate during weight bearing or stance phase of the gait cycle. Additional varus wedging to the contoured plate, up to 10 degrees, has been described. Both extrinsic posts and intrinsic posts (changes in the contour of the plate from its original configuration) are described. Numerous variations in plate width and material used for construction are recorded. Review of the patent literature identified designs as early as 1924 that contoured metal, rubber and wood to cast impressions taken from individual feet. Many orthotic laboratories, using a variety of plastics and even a scanned digital image as the foot impression currently use this contoured plate method of fabrication.

Many types and combinations of material both natural and synthetic have been used to construct the orthotic devices reviewed. Some use materials that are soft and said to "cushion the foot". Others use material that is highly resistant to deformation, with expressed intent to support or stabilize. Many incorporate materials that both support and cushion foot function.

Orthotics constructed of steel, wood, plastics and hard rubber have all been used to generate relatively rigid plates. Foam rubber, water, air and a variety of compressible materials have been used as cushions for the foot.

In general inventions designed to fill the arches used softer materials, than those who contoured a plate did. Function of a foot control devise is increased with a material less deformed during stance phase of gait. The term functional orthotic, currently used to describe semi-rigid to rigid contoured plate orthotics may be generally applied, however all foot control devices alter the function of the foot.

Bly "anatomical leg" (1858)


Ankle joint formed by an ivory ball embedded in vulcanised rubber

Ptersen H & Gocht H (1907) Amputationen und Exartikulationen. Künstliche Glieder. Stuttgart, Ferdinand von Enke

Endoprostheses

                       We owe the first total prosthesis to Th. Gluck from Berlin (1880-1890), (they were in ivory), and to Jules Pean from Paris
                       (1890-1894) (they were in platinum and cemented with plaster and pumice). Hardly successful though they were, the idea of replacing
                       an articulation by foreign material was born. It would take sixty years to come to a successful hip total prosthesis. In the 1930 ies,
                       Smith-Petersen, from Boston, designed moulds to be set between the femoral head and a cotyle in glass, pyrex, Bakelite and
                       eventually a metal cupule (vitallium) either set on to the cotyle or the femoral head. After 1940 Bohlmann and Moore were the first to
                       replace the upper part of a femur bearing a tumour and a metal prosthesis. In 1947, Jean and Robert Judet proposed a femoral head
                       in acrylic. The first successful femoral prosthesis (more than 50 % good results) was Moore's new metal prosthesis in 1950. In the
                       50ies, some surgeons had the idea of connecting the two prosthetic pieces (cupule and femoral prosthesis) to get a total prosthesis,
                       mainly in metal (Mc Kee from Norwich in 1951 and Herbert from Aix les Bains around 1955). In 1960, Charnley used dentist's
                       methalcrylate cement for a Moore femoral prosthesis. In 1962, Charnley used this cement for a total prosthesis, with the low-friction
                       concept and a 22 millimeter femoral head, which could move in a polyethylene cupule. This prosthesis is still in use today, in 1999.

Fischer LP, Planchamp W, Fischer B, Chauvin F (2000) Hist Sci Med. 34(1):57-70.The first total hip prostheses in man (1890 - 1960)