Apophysis

[ Home ] [ Up ]

Pages Below:

secondary ossification centre characteristically sited at a bony prominence which acts as the insertion site for a tendon. An apophysis is separated from the metaphysis by a physis. Unlike an epiphysis, an apophysis does not participate in longitudinal growth and does not form an articular surface. As in the case of the proximal tibial, a secondary ossification centre occasionally forms both an epiphysis and apophysis.

2. Pathology

An apophysis is prone to acute or chronic avulsion injury as a result of tension forces from attached musculature. Acute apophyseal avulsion fracture are most common during the second decade just prior to physeal fusion. Common sites include the anterior inferior iliac spine, anterior superior iliac spine, ischial tuberosity, iliac crest and medial epicondyle of distal humerus. Apophysitis describes a chronic traction injury to an apophysis seen particularly in athletic children. There is swelling of the structural cartilage and fragmentation of the ossific nucleus, and there may be associated oedema of the overlying extraosseus soft tissues. Common sites include the tibial tuberosity, Osgood Schlatter disease, various apophyses within the pelvis and the calcaneus. MRI will demonstrate reduced signal on T1- and increased signal on T2-weighted or STIR sequences, particularly within the fatty marrow of the secondary ossification centre.

[ Home ] [ Up ]