Simple bone cysts: The effects of methylprednisolone on synovial cells in culture

Ten years ago, a protocol using Depo-Medrol injections was developed for the treatment of unicameral bone cysts. This concept, designed by tumor surgeons and based on theory, has been cautiously approached. However, reproducible results have gradually increased clinical acceptance. Understanding the healing process has been restricted because of the lack of an experimental model. In an attempt to elucidate this mechanism of healing, a cell culture model was used to investigate the effects of methylprednisolone on synovial cells. Initially, three doses of the drug were tested and maximal changes were noted with the concentration of 40 mg/ml. Changes were then quantified by morphology, DNA assay, cell protein analysis, and electron microscopy. Results suggest that methylprednisolone may have a direct effect on the cellular component of unicameral bone cysts.