The Upper Limb

This chapter focuses on the components of the upper limb with emphasis on the humerus, the radius, the ulna, and the hand. The perinatal humerus is more robust than the radius, ulna, and fibula. The proximal humeral epiphysis is smaller than the femoral head during early development. The capitulum is the only distal center that is likely to be recognized in isolation. It is wedge-shaped, with a wider lateral end. This chapter then moves to the discussion of the radius. The perinatal radius is more gracile than the humerus, femur, and tibia, and shorter than the ulna and fibula. It is characterized by its tuberosity and flared distal end. The distal epiphysis increasingly assumes a triangular wedge shape, although this is less obvious during its early stages of development. The perinatal ulna is more gracile than the humerus, femur, and tibia; longer than the radius; and similar in length to the fibula. The distal ulnar epiphysis bears a distinct notch; the distal radial epiphysis is round. This chapter then turns the discussion to the hand. Metacarpals become more recognizable as ossification spreads into the bases. Identification of individual metacarpal heads is difficult and generally relies on the presence of a single individual so that an appropriate head can be fitted to a shaft. This chapter also explains bases of the middle phalanges and bases of the distal phalanges. It also has an account on metrics, general development, and union times, which are explained with the help of various references.