“What God has joined together, let no man put asunder” ... but sometimes God’s handiwork needs a little help. Replacement joints and prostheses can mimic or even improve upon nature’s own design, with high-tech materials and sophisticated manufacturing techniques. Prostheses (artificial limbs) and implants (replacement joints) are the means we mere mortals have devised to restore functionality to damaged or diseased body parts. Modeled after nature’s own shapes and textures, these devices often have a surreal beauty all their own.

“The reason they are so beautiful,” says Lorraine Potocki from Smith-Nephew, one of the leading suppliers of replacement joints, “is precisely because they are made to be implanted in a human body.” Robert Brosnahan, Smith-Nephew’s VP of Product Development, explains, “We take CT scans of a broad cross-section of patients’ knees, for example, bring them into a CAD system, then try to replicate the shapes. They are very sculptural; we are looking for something smooth and sleek because we want a smooth load transfer … if there is abrupt geometry, then the load transfer is abrupt.” Although most of Smith-Nephew’s designers come from mechanical or aeronautical engineering backgrounds, Brosnahan says, “One of the things we do when hiring is to measure candidates’ creativity.”

Another leading firm for implants is Zimmer. Spokesperson Brad Bishop avers that “design is driven by functionality” in the field of implants. Materials like titanium alloy, cobalt chrome alloy, and special surfaces developed to reduce friction-related degradation such as ultra-high molecular polyethylene are integrated into the flesh-and-bone environment, and they must join seamlessly with nature’s own. Implants are not seen once the surgery is complete, yet patients can take a measure of pride in their beautiful new “parts.”

In the case of paraolympic athletes, whose specialized prostheses are designed for one event only, their artificial limbs are not disguised at all but take on a clearly technical, futuristic, streamlined appearance. Triathlete Sarah Reinertsen, who was recently featured on the cover of Runner’s World, utilizes two diΩerent prostheses for a triathlon (she doesn’t wear one for swimming). One prosthesis has a running shoe for the marathon portion and the other has a bike cleat bolted to it.

Although some prostheses are designed for a specifi c athletic purpose, most are custom-designed to duplicate the surviving limb. Great care is taken to create an individual shape, visual appearance, and texture that is undetectable from the original. High-profi le amputees such as Paul McCartney’s wife, Heather Mills, have brought new attention to lifelike and functional artificial limbs, but the need for prostheses has been around for a long time. Military injuries and farming and industrial accidents are the leading causes of limb loss; medical conditions, such as diabetes and auto accidents, can also be responsible.

Enter the certified prosthetist-orthotist. These practitioners often have interestingly diverse backgrounds, merging science, medicine, and art in the search for functionality and lifelike form. Dennis Horn, a certifi ed prosthetist-orthotist from Miami’s HealthSouth, says that the art component of his job is in having the hand skills to shape the prosthesis for each individual patient. “I learned the artistic aspects on the job,” he notes. “I couldn’t draw a straight line, but now I can sculpt a leg like you wouldn’t believe. Everything is customized.”