Fifth metacarpal bone Fifth metacarpal bone The fifth metacarpal bone (metacarpal bone of the little finger or pinky finger) is the most medial and second-shortest of the metacarpal bones. It presents on its base one facet on its superior surface, which is concavo-convex and articulates with the hamate, and one on its radial side, which articulates with the fourth metacarpal. On its ulnar side is a prominent tubercle for the insertion of the tendon of the extensor carpi ulnaris muscle. The dorsal surface of the body is divided by an oblique ridge, which extends from near the ulnar side of the base to
Artificial bone which is one of the most stable forms of calcium phosphate, makes up about 60 to 65 percent of the bone. The rest of the bone is composed of materials including chondroitin sulfate, keratan sulfate and lipid. Increased research and knowledge regarding the organization, structure of properties of collagen and hydroxyapatite have led to many developments in collagen-based scaffolds in bone tissue engineering. The structure of hydroxyapatite is very similar to that of the original bone, and collagen can act as molecular cables and further improve the biocompatibility of the implant. In the United States, more than 6.5 million bone