Flexible intramedullary nailing for the treatment of unicameral bone cystsin long bones

Background: Unicameral bone cyst is characterized by its tenacity and risk of recurrence. Pathological fracture is common and is often the presenting symptom. The objective of the present study was to evaluate the results of flexible intramedullary nailing for the treatment of a unicameral bone cyst with or without a pathological fracture. Methods: Flexible intramedullary nailing for the treatment of a unicameral bone cyst was performed in thirty-two patients. Thirty of these patients pr esented with a pathological fracture; twenty-four were managed immediately with intramedullary nailing, and the other six had been managed conservativ ely at other clinics before they were referred to our department. The remai ning two cysts were detected incidentally. The cyst was located in the hume rus in twenty-one patients, in the femur in nine, and in the radius in two. The mean age of the patients at the time of surgery was 9.8 years, and the mean duration of follow-up was 53.7 months. Radiographic evaluation was pe rformed according to the criteria of Capanna et al,, and the cyst was class ified as completely healed, healed with residual radiolucency (osteolysis), recurred, or having no response. Results: The healing period ranged from three to 105 months. Fourteen cysts healed completely, and sixteen healed with residual radiolucent areas visi ble on radiographs. There was recurrence of two cysts that had healed with residual radiolucency. All of the cysts in the present study responded to t reatment. A change of nails was necessary in nine patients, as the nails ha d become too short after bone growth. No major complications were observed. Conclusions: Flexible intramedullary nailing provides early stability, whic h allows early mobilization and thus obviates the need for a plaster cast a nd decreases the prevalence of the most common complication: a pathological fracture. This method of treatment also allows for an early return to norm al activity.