A surgically implantable metacarpal-phalangeal prosthetic replacement device having engaging male and female components. The male and female components each include a conically shaped shank adapted to be inserted into a medullary canal of a bone. The male head portion connected to the first conically shaped shank includes two spaced-apart lateral condyles having convex condylar surfaces and an intercondylar portion juxtaposed between the first and second convex condyles. The intercondylar portion extends outwardly relative to the convex condylar surfaces. The female component has a female head portion connected to the second conically shaped shank. The female head portion includes spaced-apart lateral side portions having concave recessed load-bearing surfaces that are complementary to and moveably engage the convex condylar surfaces of the male component. The lateral sides portions further define an intermediate concave condylar recess that moveably engages the outwardly extending intercondylar portion. The female head portion further includes dorsally positioned and substantially longitudinally aligned first and second protuberances which define a median channel portion for reception of the extensor tendons.
