A team from the University of Melbourne in Australia, led by biomedical engineer Peter Vee Sin Lee, fitted 70 patients in Vietnam with prosthetic sockets using pressure cast (PCAST) technology.
A below-knee prosthesis consists of the socket — the connection between the user and the prosthesis — the shank and the foot. While the shank and the foot can be assembled using standard polypropylene components, the socket has to be customised to every patient’s need by a prosthetist.
“PCAST technology would be particularly useful in natural disasters and emergency situations to get people walking as soon as possible.”
Peter Vee Sin Lee, University of Melbourne, Australia,
“PCAST takes less than 15 minutes to cast the socket. It doesn’t require any modification or adjustment by a prosthesis,” says Lee. “The technique is suited for sockets needed by the largely trauma victims in developing countries.”
However, Lee adds that more research will be needed for complex cases such as diabetes and vascular related amputations.
To fabricate a PCAST socket, the residual limb is wrapped in a plaster bandage and placed into a water tank. As the water rushes in, the pressure moulds the plaster cast to the exact shape of the patient’s residual limb. A polypropylene sheet is draped on the mould and heated in an oven to create the socket, which is then fitted to standard components for the shank and foot.
“Being easily portable, the PCAST technology would be particularly useful in natural disasters and emergency situations to get people walking as soon as possible,” says Lee.
The scientists have been working with the Vietnamese Training Centre for Orthopaedic Technologists (VIETCOT) in Hanoi, Vietnam, and plan to take the PCAST technology to Cambodia, Laos and Myanmar.
“About 400 patients have benefitted from this technology and have found it very comfortable. In Vietnam, a prosthesis costs US$130 and takes eight hours to make whereas the PCAST prosthesis costs US$100 and takes about four hours to [complete],” VIETCOT director Nguyen Hai Thanh says. According to a 2004 WHO report, more than 75 percent of developing countries have no prosthetics and orthotics training programmes.
Louise Puli, chairwoman of the International Society of Prosthetics and Orthotics’ Australian Outreach Committee, says some island countries in the Pacific have no prosthetic service at all. In Africa, the estimated need for prosthetists is about 10,000 professionals, but the current number is less than 400.
Based on her experience in public health as a prosthetist and orthotist in Australia, Cambodia and Tanzania, Puli says: “There are good quality low-cost prosthetic parts available in developing countries, but even the very best technological prostheses will not be accepted by the patient if the socket has not been accurately cast and fabricated.”
This piece was originally produced by SciDev.Net’s South-East Asia & Pacific desk.