Evaluation of volume and solitary bone cyst remodeling using conventional radiological examination

To evaluate cyst remodeling, including complete healing and recurrence, and its relation to the cyst volume in two groups of patients, using curettage and bone grafting or methylprednisolone injection.

A retrospective analysis was carried out on data from 132 patients with solitary bone cyst, where 79 (59.9%) had undergone curettage and bone grafting and 53 (40.1%) had been administered methylprednisolone injection, with a mean time to follow up of 12 years. The cyst volume was evaluated from conventional radiographs and the method originally reported by Göbel et al. to evaluate the volume of Ewing's sarcoma. The results were analyzed using the criteria of Neer et al. and Capanna et al.

The mean cyst volume was 36.8 cm(3). Recurrence was noted in 16 (20.2%) patients treated with curettage and in nine (17.0%) treated with methylprednisolone. Cyst volume in patients treated with curettage and bone grafting ranged from 8.3 cm(3) to 100.0 cm(3) and with methylprednisolone from 14.0 cm(3) to 50.6 cm(3) . In neither group was the cyst volume related to recurrence. Volumes from 1.3 cm(3) to 81.9 cm(3) were stated for patients treated with curettage and bone grafting, when complete healing was observed; they were significantly lower than for those of the total group of patients who underwent curettage and bone grafting.

1. An association between solitary cyst volume and recurrence in patients treated with either bone curettage and grafting or methylprednisolone was not found. 2. The frequency of complete healing in patients treated with bone curettage and grafting decreased with an increase in the cyst volume.