Abstract
1. Two boys complaining of pain in the ankle were shown to have centres of separate ossification for the medial malleoli. These were present bilaterally, but discomfort was unilateral.
2. In one, followed for fifteen months, the extra centre became wholly incorporated into the normal lower tibial epiphysis.
3. in a series of 100 children between the ages of six and twelve, without any known disease or injury of the ankles, radiographs showed that 20 per cent had a separate medial malleolar centre on one side. In 13 per cent this finding was present bilaterally. In one child a separate lateral malleolar centre was also found.
4. The significance of this finding is discussed, and it is considered to be a normal variant.
5. Occasionally one of these centres may remain unfused into adult life. Attention is drawn to the possible implications of this persistence.
