Pinned elbow fracture. Coloured X-ray showing metal pins (black) in a fracture at the elbow joint due to osteoporosis (brittle bone disease). Bone is pale blue with flesh pale green. The elbow joint is where the humerus (upper-arm bone, upper right) meets the two smaller forearm bones, the radius and ulna (lower left). Broken bones must be aligned and held in place to ensure that they heal properly. Osteoporosis is characterised by weaker bones that are more liable to fracture.