Elastic stable intramedullary nailing for the treatment of complicated juvenile bone cysts of the humerus.

Juvenile bone cysts usually are asymptomatic and may manifest as pathological fractures. Since the new method of flexible intramedullary nailing (" Elastic Stable Intramedullary Nailing" - ESIN or " Embrochage Centro- Médullaire Elastique Stable" - ECMES) has demonstrated superb results in the treatment of non-pathologic fractures of the long bones in childhood, this method is rapidly gaining popularity for the treatment of spontaneous or pathological fractures. Given the self-limiting natural history of juvenile bone cysts with eventual spontaneous healing, our goal is to stabilise the pathological fracture and the biomechanically weakened humerus. We treated 15 patients with 16 pathological fractures (one re-fracture) due to juvenile bone cysts of the proximal humerus. All fractures healed completely without pseudarthrosis. Complications were a secondary fracture in otherwise correctly positioned nails. Five of the 15 implants remain in situ, in 6 cases a repeat osteosynthesis was necessary, in one case the nails had to be changed because of the re-fracture. Ten of the 15 juvenile bone cysts healed over a period of 3 years, the nails were removed and so far there have been no further fractures in this group. In the other 5 cases, the juvenile bone cysts have progressively filled with sclerotic bone, and the nails remain in situ.