Simple bone cysts of the calcaneus. Differential diagnosis and therapy

Fifty-two calcaneal simple bone cysts from our clinic were evaluated. The lesions had a pathognomonic radiologic appearance and diagnosis was histologically confirmed in all operatively treated cases. Four cases presented with pathological fractures, three of which were treated by open reduction internal fixation and bone grafting, while one was treated nonoperatively. In addition, six patients with large cysts without apparent fracture but spontaneous pain were treated by curettage and subsequent autogenous bone grafting or calcium phosphate cement filling, and there were no recurrences. The majority of cysts (42 of 52) were however asymptomatic and thus followed up nonoperatively. This review reports on one of the largest series of cysts in this location. The results indicate that nonoperative management is justified in most asymptomatic cases. However, the potential risk of fracture as indicated by four fractured calcaneal cysts in this series suggests that large cysts should be clinically monitored and that operative intervention is useful in all symptomatic cases to prevent pathologic fractures. In the latter cases, curettage and bone grafting as well as the use of bone substitute material yielded uniformly good results.