The Novel Design of the Mercer Universal Prosthesis

Abstract

The Mercer On Mission (MOM) Orthopedic and Prosthetic projects are addressing a worldwide problem, which is predominantly critical in Vietnam and Southeast Asian countries. More than 2000 Vietnamese are injured each year by landmines and unexploded bombs left over from the Vietnam War. An estimated 100,000 amputees live in Vietnam today, and there are more than 18 million amputees around the world, with more than 80% of those living in developing countries. The prosthetic device was invented by one of the authors. The innovative design features a “V-cut” in the back of the socket, allowing the amputee patient to adjust the volume of the socket opening as the size and shape of patients’ stump changes. This adjustability is a principal advantage, as standard prostheses generally need to be replaced every two to three years because they no longer fit. This is not financially possible for many impoverished Vietnamese amputees. The prosthetic sockets and feet are made using injection molds. Knee joints, pylons and flanges are made using CNC and milling machines. They are made of polypropylene and aluminum instead of carbon fiber and stainless steel or titanium alloys. Therefore, the universal below the knee (BK) and above the knee (AK) prostheses are much lighter than the customized ones. At a cost of only $100 USD per BK and $150 USD per AK prosthesis to manufacture, coupled with grants and donations to cover material costs, the program is able to provide prostheses to Vietnamese amputees free of charge. Since 2009, authors with faculty and students from Mercer University have traveled to Ho Chi Minh City, Can Tho, Phung Hiep, Ben Tre, Phong Dien, Dong Thap, Ca Mau, Vinh Long, Vung Tau, and Quang Tri numerous times, bringing a total of 4816 Mercer prosthetic devices to fit for the local patients.