Immobilization of an injured limb with a rigid shell is a medical technique that has been practiced for thousands of years, evolving from simple splints to the modern cast. A medical cast provides external support to stabilize a fractured bone or dislocated joint, preventing movement so the natural healing process can occur. The history of this device is not marked by a single invention but by a continuous evolution of materials, driven by the desire for greater rigidity, faster application, and increased patient comfort.
Ancient Techniques and Early Splints
The practice of immobilizing broken bones dates back at least to the ancient Egyptians around 3000 BC, who developed early methods of external fixation. They used simple materials readily available, such as wooden splints made from bark or reeds, which were then wrapped in linen and stiffened with resin or gum from plants.
Later, the ancient Greeks, notably Hippocrates around 350 BC, described treating fractures by wrapping limbs in bandages soaked in a mixture of wax and resin. As the mixture cooled and dried, it would form a relatively stiff encasement around the injury. These techniques were significant improvements because they provided a more conforming fit than simple wooden splints, though they still relied on slow-drying, natural substances.
During the Roman era and into the early 19th century, practitioners continued to experiment with various stiffening agents, including materials like corn starch, egg whites, and flour. The starched bandage technique, or “bandage amidonnee,” popularized by Belgian surgeon Louis Seutin in the 1830s, involved soaking linen strips in a starch solution. This method created a solid, supportive shell once dry, but it often required two to three days to fully harden, which was impractical for immediate battlefield use and patient transport.
Even with the use of materials like plaster or clay mixed with egg whites, as described by Arab physicians around 800 AD, these early methods were often heavy, cumbersome, and required the patient to remain immobile for extended periods while the material cured. The starched bandage technique, popularized in the 1830s, required two to three days to fully harden, making it impractical for immediate battlefield use and patient transport. These slow-drying, organic-based supports highlighted the need for a quick-setting, rigid material.
The Plaster of Paris Innovation
The invention of the modern, rapidly setting cast is attributed to the Dutch military surgeon Antonius Mathijsen in 1851, marking the true birth of the orthopedic cast as it is known today. Mathijsen was working in the military hospital in Haarlem and was seeking a better way to treat soldiers’ fractures quickly and effectively. He introduced the revolutionary concept of using a bandage impregnated with Plaster of Paris, a readily available material used for centuries in construction and art.
Plaster of Paris is chemically known as calcium sulfate hemihydrate, which is created by heating gypsum to remove most of its water content. When mixed with water, it quickly undergoes a chemical reaction called hydration, reverting to a solid, rigid form of calcium sulfate dihydrate. Mathijsen’s technique involved rubbing the fine gypsum powder into coarse cotton or linen strips to create a flexible bandage that could be stored dry.
When the impregnated bandage was moistened with water, it could be quickly wrapped around the injured limb, conforming precisely to its shape. This mixture would harden within minutes, providing a rigid, custom-molded support that was a massive leap forward in fracture management.
Mathijsen published his findings in a Dutch medical journal in 1852, detailing his “new method of using the plaster cast for broken bones.” The technique gained international recognition and was used with notable success during the Crimean War (1853–1856), where it proved invaluable for stabilizing battlefield fractures and enabling the safe transport of wounded soldiers. This innovation effectively minimized infection rates, reduced pain, and improved patient outcomes compared to the heavy, slow-setting alternatives.
Synthetics and Modern Casting Technology
Plaster of Paris remained the standard for fracture immobilization for over a century, but its inherent drawbacks—namely its weight, susceptibility to moisture damage, and lack of breathability—eventually spurred the development of newer materials. The next major advancement came in the 1970s with the introduction of synthetic casting materials, particularly those based on fiberglass.
Fiberglass casts, made from glass fibers embedded in a polyurethane-based resin, were developed to overcome the limitations of the traditional plaster cast. This material is significantly lighter than Plaster of Paris, often weighing only one-third as much, which greatly improved patient comfort and mobility. The synthetic resin also hardens quickly after being exposed to water, often achieving functional rigidity in just a few minutes.
Beyond being lightweight, fiberglass offered other benefits, including greater durability and a higher degree of water resistance, though the cotton padding underneath still posed a challenge when wet. The material is also more radiolucent, meaning it allows X-rays to pass through more easily, giving doctors a clearer view of the healing bone without having to remove the cast. These advantages led to fiberglass largely replacing Plaster of Paris for definitive, long-term fracture immobilization.
The evolution continues with modern technologies, including the use of advanced thermoplastics and custom 3D-printed casts. These emerging devices can be designed with latticework structures, offering ventilation and being fully waterproof, which eliminates the moisture issues of prior materials. Though still facing challenges in cost and accessibility, these technologies represent the ongoing pursuit of a lighter, stronger, and more comfortable solution for stabilizing broken bones.