1 . This case of post-traumatic osteochondritis of the lower tibial epiphysis is important because the condition is rare.

2. The similarity to osteochondritis in other sites dating from a single injury is noted.

3. The ankle joint bears more body weight per surface area of articular cartilage than other weight-bearing joint surfaces. It is of interest that regeneration took place in spite of the fact that the child continued to bear weight and that the joint was immobilised for only two months, beginning four months after the original injury.