Excessive pull by a large tendon causes damage to the unfused apophysis to which it is attached

Osgood-Schaltter's disease

• Traction apophysities at tibial tubercle - insertion of patellar tendon into tibial tuberosity
• Occurs in adolescent active boys

Clinical features

• Seen in sporty teenagers
• Pain, tenderness and swelling over the tibial tubercle

Other sites

• Can also happen at patella and Achilles