Results of the local steroid injections in the simple bone cyst

Objectives: Steroid injections represent one of the simple treatment alternatives for simple bone cysts. The aim of this study was to evaluate the results of local steroid injections in the treatment of simple bone cysts. Methods: Seventeen patients (11 male, 6 female; mean age 12.4 years; range 2 to 39 years) with simple bone cysts were treated with injection of methylprednisolone acetate with the use of the two-needle technique. The cysts were localized in the proximal humerus (n=6), the calcaneus (n=2), proximal femur (n=7) and the tibia (n=2). Pathological fractures occurred in three patients before steroid injection. These three patients with pathological fractures were treated with injection of methylprednisolone after healing fractures. Each patient received a maximum of four injections at eight week intervals, each consisting of 40-160 mg of methylprednisolone acetate. The patients were followed by plain radiographs obtained in the first month, third month, sixth month, and at the end of a year. After the first year, patients were followed up with plain radiographs once a year. The mean follow-up was twenty two months (range 3 to 48 months). Cyst healing was assessed according to the Neer classification. Results: Treatment with methylprednisolone acetate resulted in complete healing in ten cysts (55%) and healing with residual lesions in three cysts (17%). Three patients (17%) did not respond to steroid treatment and two patients (11%) developed recurrence. The results were satisfactory (72%) in patients with complete healing and healing with residual lesions, and unsatisfactory in five patients (28%). The patients with recurrency were treated with curettage and grafting or curettage and cementation. No procedure-related complications were encountered. Conclusion: Our findings suggest that, the treatment with local steroid injection in simple bone cyst provide satisfactory results, thus this treatment with low morbidity can be applied to these patients which of them are mostly children before aggressive treatment. Key words: Bone cysts/drug therapy; injections, intralesional; methylprednisolone/therapeutic use; steroids/therapeutic use.