Autologous bone marrow injection in the management of simple bone cysts in children.

The majority of simple bone cysts (SBC's) is not symptomatic and remains undiagnosed or is discovered fortuitously. A number of simple bone cysts are only diagnosed after a pathological fracture which occurs as a presenting symptom. Fractures are managed either conservatively or surgically, based on criteria such as the age of the child and the type and localisation of the fracture. The risk for fracture can be evaluated radiographically. In the absence of a fracture risk, plain radiographic follow-up is sufficient. In case of a high fracture risk, percutaneous aspiration and injection of bone marrow may be performed. The result of this treatment in 21 simple bone cysts with a high risk for fracture is reported. Slow regression of the cyst and progressive healing were obtained in 15 cases (71.4%) whereas no response was noted in 3 cases (14.3%) and recurrence in another 3 (14.3%), after a mean follow-up of 37.1 months. Guidelines are proposed for the follow-up and management of SBC.