Fatigue infraction of the middle of the tibia in ballet dancers.

Case 1-Defect of left tibia. Biopsy. A male ballet dancer aged twenty-three began to suffer a stab of pain in the middle of the front of his left shin when landing on this leg from leaps. A few days later while pulling on his socks he chanced upon a small tender hard lump at about the middle of the crest of his tibia. He did not limp, and he paid no attention at first, but the lump became larger and more tender.