In a waiting room in Stung Meanchey last week, 21-year-old Ouk Vy sat patiently as technicians fitted him with a small socket to connect his right leg – which was amputated at the knee last year after a traffic accident – to a new prosthetic limb.

Vy then stood and took a step forward, as he has many times before.

This new socket is different from others he has worn out: it is the first to be made from a scan and then manufactured from scratch in just a few hours in the only 3D-printing lab for below-the-knee (more technically, “trans-tibial”) prostheses in Cambodia. The lab began its first clinical trial last week, and Vy was first in line.

Many standard prostheses have a lifespan of only a few years – and just a few months for growing kids. That means a lot of re-fittings. At its core, the 3D-printing process mirrors that of being fitted for a normal prosthesis; it’s just easier – and, ideally, more comfortable for the patient.

Traditionally, a prosthetist – someone who makes prosthetic items (which are known in the trade as prostheses) – would wrap a limb at the stump to protect it; then make a plaster mould; then cut it off, fill it in, strip the bandage and wait for the plaster to dry. But with a 3D scanner, a digital replica of a limb can be made in just a half hour – and there’s no mess.

“That is the holy grail as a prosthetist,” says Ken McCrea, the Scot who oversees the project. “Getting exactly what you want. And it’s replicable.”

Moreover, that model then exists on a computer and can be digitally tweaked for particularities rather than with hand tools. Finally, an operator sends the data to the printer and within three to nine hours – depending on whether it’s a socket or something larger – a polypropylene copy appears.

The four-month clinical trial applies existing, relatively inexpensive technology in a new way to address a persistent problem: the demand for new prostheses in a country like Cambodia.

McCrea is the head of UK-based Exceed Social Enterprises, which is running the project here in partnership with Nia Technologies, a non-profit that has piloted two trials in Uganda.

During the trial, the patients must fit “precise criteria”: they must be aged between five and 25, and they must be able to walk and to communicate well. For now, the technicians are working with 50 clients for whom they are printing 30 sockets and 30 orthotic inserts.

The new 3D printing lab is part of a private clinic that opened in Stung Meanchey district last August under the aegis of Exceed, known locally as the Cambodia Trust. The organisation was established here in 1989 to provide a desperately needed – and cost-free – service to landmine victims, and it has since replicated its model in the Philippines, Indonesia, Sri Lanka and Myanmar.

And so the private clinic, where “some [prostheses] can run to $5,000 just for a foot”, McCrea says, funds the charitable one.“We’re basically doing the Robin Hood principle: robbing the rich to pay the poor,” he explains. “Those who can afford it buy something here, we make a little profit, and then we can use that money to feed back into the charity centre.”

Sisary Kheng, Exceed’s country director, is a familiar face in every room at the public centre, which is located about a kilometre from the private clinic. The centre has many rooms: for fittings, for production and for learning. Also on site, and part of the Cambodia Trust, is the Cambodian School of Prosthetics and Orthotics (CSPO), which has a three-year residential training program. Kheng has watched the Cambodia Trust grow from its beginnings, when 95 per cent of its patients were landmine victims.

Years of demining efforts mean Cambodia’s worst landmine days are behind it. Since the start of 2016, landmines and explosive remnants of war (ERW) killed 23 people, injured a further 23 and caused an additional 13 to lose limbs.

That’s fewer than the same period last year, continuing what has been a largely year-on-year decline in casualties. But there are still 8,995 surviving landmine victims in need of artificial limbs. Most are men and boys, and many come from poor backgrounds.

These days it is traffic accidents that are one of the primary causes of disability in Cambodia. Kheng says thousands more patients require braces or orthotics for support: kids with poliomyelitis, spina bifida or cerebral palsy.

The Cambodia Trust has more than 15,000 clients in its database, and its technicians make 3,500 prostheses per year between their clinics. (The organisation operates one more clinic in Preah Sihanouk province and another in Kampong Cham.)

Last week, a man waited patiently in the lobby of the Phnom Penh centre to be measured for a new limb. He lost his leg to a landmine in 1984; his most recent prosthesis was damaged in a motorbike accident last month.

The most basic trans-tibial prosthesis would usually cost up to $182, but at the public centre, his was free. In an adjacent room, a six-year-old child with cerebral palsy – under the care of local NGO Pour un Sourire d’Enfant (PSE) – was fitted for a wheelchair.

Medical students come from across the globe to study at CSPO, which has a three-year residential training program. Last week saw students from Myanmar, Malawi, Samoa and Kiribati. Yet in its classrooms and production rooms, the Cambodia Trust’s centre still relies on traditional methods: setting a mould around a limb; adjusting it by hand; and wrapping hot plastic around it once it has set.

“The complete process maybe takes three days,” says Kheng. Watching the 3D-printing process at the private clinic nearby, it’s easy to imagine this time could be dramatically shortened. But that’s not likely to happen soon.

“3D printing isn’t particularly new, and scanning using electronic data capture for patients is not new either,” says McCrea. “But the two of them have really been successfully used together [in this project].”

And if the clinical trial proves the concept, perhaps the 3D-printing model – like the product itself – will one day be replicated in Cambodia Trust’s centres around the country.