Summary of Ossification Patterns

BONE                                    OSSIFICATION CENTER                           AGE AT APPEARANCE                       AGE AT FUSION

Scapula                        Body (primary)                                 8 wk (fetal)
Coracoid (tip)                                   1 yr

Coracoid                                                          15 yr
Acromion                                         15 yr
Acromion                                         16 yr
Inferior angle                                    16 yr
Medial border                                   16 yr

Clavicle                                 Medial (primary)                                            5 wk (fetal)                                                   25 yr
Lateral (primary)                               5 wk (fetal)

Sternal                                                             19 yr

Humerus                      Body (primary)                                 8 wk (fetal)                                      Blends at 6 yr and unites at 20 yr

Head                                                                 1 yr
Greater tuberosity                             3 yr
Lesser tuberosity                              5 yr
Capitellum                                        2 yr                                                        Blends and unites with body at 16-18 yr

Medial epicondyles                          5 yr
Trochlea                                                          9 yr
Lateral epicondyles                          13 yr

Ulna                                       Body (primary)                                               8 wk (fetal)

Distal ulna                                                       5 yr                                                                 20 yr

Olecranon                                                       10 yr                                                               16 yr
Radius                                   Body (primary)                                               8 wk (fetal)

Distal radius                                                   2 yr                                                                 17-20 yr
Proximal radius                                             5 yr                                                                 15-18 yr

Pelvis                                    Ilium (primary)                                                2 mo                                                               15 yr
Ischium (primary)                                          4 mo                                                               15 yr
Pubis (primary)                                              6 mo                                                               15 yr
Acetabulum                                                    12 yr                                                               15 yr

Tibia                                       Body (primary)                                               7 wk (fetal)

Proximal (secondary)                                  Birth                                                               20 yr

Distal (secondary)                                        2 yr                                                                 18 yr
Fibula                                     Body (primary)                                               8 wk (fetal)

Proximal (secondary)                       3 yr                                                 25 yr
Distal (secondary)                                        2 yr                                                                 20 yr