Madrid hospital implants world's first custom metamaterial bone prosthesis

The Hospital General Universitario Gregorio Marañón in Madrid has designed, manufactured, and implanted the world's first personalized metamaterial bone prosthesis, avoiding the amputation of a 38-year-old patient's leg. The implant, made of a titanium alloy via 3D printing, was developed using aerospace technology and mimics the mechanical behavior of bone. Weighing just 300 grams, it can support over 500 kilograms, compared to conventional prostheses that weigh several kilos and support 100–150 kilos Source: infobae, euronewses.

The case

Pierre Chazel, a French patient, had a high-grade bone sarcoma in his tibia. After an infection and severe bone density loss, a conventional implant was not viable, leaving amputation as the only option. The team, including surgeons and engineers from the Universidad Politécnica de Madrid (UPM), created a digital twin of his healthy leg to simulate loads and design the internal structure point by point Source: elconfidencial, elmundoes. The prosthesis was filled with cancellous bone from the hospital's bone bank to promote integration Source: infobae.

Outcome and next steps

Nearly a year after surgery, Chazel has no infections or complications, maintains knee mobility, and walks without crutches Source: elconfidencial. The hospital, a national reference center for sarcomas, has already operated on two more patients with similar technology and plans to develop a standard protocol to treat more patients Source: elmundoes. The cost of the 3D-printed implant is around €3,000, significantly less than conventional ones Source: infobae.

Disagreement

While all sources agree on the implant's weight and load capacity, there is a slight discrepancy: infobae reports the patient can walk "in many cases without crutches," whereas euronewses states he "already can walk" and has "begun to recover mobility," without specifying crutch use. This difference likely reflects the patient's progress over time.