Clinical outcome following surgical intervention for a solitary bone cyst: emphasis on treatment by curettage and steroid injection

Abstract

BackgroundSolitary bone cysts are benign, fluid-filled, expansive lesions in children. The success rate of bone consolidation in the case of a solitary bone cyst is unpredictable following steroid injection. MethodsAmong 24 patients with a solitary bone cyst, 11 (femur 8; pelvic bone 3) underwent curettage plus bone grafting for stabilization. The remaining 13 patients — 8 long bones (humerus 6; femur 2) and 5 non-long bones (calcaneus 5) — underwent curettage plus steroid injections. ResultsAmong the 11 patients, 2 treated by curettage plus bone grafting suffered recurrence and needed a second procedure. One of the 13 patients treated by curettage plus steroid injection as the initial treatment later developed a pathological fracture and underwent bone grafting. The remaining 12 patients treated by curettage plus steroid injection eventually achieved bone consolidation, after an average of 1.6 injections (range 1–3). One injection was enough to achieve bone consolidation in two of seven of the long-bone cases (29%) and in all of the five non-long-bone cases. ConclusionsSteroid injection remains a useful method for treating solitary bone cysts owing to its low invasiveness. The very favorable results achieved in the five calcaneus cases following a single steroid injection may be attributable to curettage. Regardless of the relatively small number of cases, the different prognosis between long bones and the calcaneus following the same procedure suggests a varying pathogenesis and/or etiology among solitary bone cysts.