The distribution of bone islands and juxta-articular bone cysts in the growing hand.

Bone islands and juxta-articular bone cysts are relatively common incidental findings when X-rays are taken for other purposes. We have identified that the incidence of bone islands in the hands of asymptomatic children between the ages of 5 and 13 years is 3.8% and the incidence of cysts in the same population is 2.8%. Bone islands were most common in the scaphoid, whilst juxta-articular bone cysts were most common in the capitate. The age at which they appear has not been reported previously. This study first identifies their presence in the hands of children of age 10 years and 2 months (bone islands) and 10 years 0 months (juxta-articular bone cysts). Most of the lesions were already present on the first radiograph taken. New bone islands appeared in five cases between the ages of 13 years and 1 month and 15 years and 3 months. New juxta-articular bone cysts were observed to appear in five cases between the ages of 10 years 10 months and 15 years 0 months. No island or cyst changed in size during the review period.