Treatment of simple bone cysts with methylprednisolone acetate in children

Steroid injections represent one of the simple treatment alternatives for simple bone cysts in pediatric age group. The aim of this study was to evaluate the results of steroid injections in the treatment of simple bone cysts. Thirteen children (9 boys, 4 girls; mean age 9 years; range 4 to 14 years) with simple bone cysts were treated primarily with injection of methylprednisolone acetate with the use of the two-needle technique. The cysts were localized in the proximal humerus (n=7), femoral intertrochanteric region (n=4), and the proximal one-third of the femur (n=1). Four patients had fractures before treatment. Each patient received a maximum of three injections at six-week intervals, each consisting of 120-160 mg of methylprednisolone acetate. The patients were monitored by plain radiographs obtained in the sixth week, third month, sixth month, and at the end of a year followed by annual radiographic evaluations. Cyst healing was assessed according to the Neer classification. The mean follow-up was five years (range 1 to 11 years). Treatment with methylprednisolone acetate resulted in complete healing in five patients (38.5%) and healing with residual lesions in six patients (46.2%). One patient (7.7%) did not respond to steroid treatment and one patient developed recurrence. The results were satisfactory (84.6%) in patients with complete healing and healing with residual lesions, and unsatisfactory in two patients (15.4%). No procedure-related complications were encountered. Our results suggest that treatment with steroid injections offers satisfactory outcome in simple bone cysts in children, and thus, is worthy of consideration before more aggressive methods are to be applied.