Hi Malik,
As a resident you would be eligible for care through the Caja, Costa Rica’s universal healthcare system. After paying a low monthly fee based on income, your care is free. Prosthetic care should be available. There are also private providers. One I’ve heard of practices just outside San Jose – his name is Dino Cozzarelli. He’s an expat himself. In general any repair work will have to be done in San Jose – it’s the center of medical specialties in Costa Rica.
Jason