To assess the performance of calcium sulphate pellets as a bone graft substitute in an Orthopaedic Oncology practice using clinical and radiological outcomes.

Between 1998 and 2001, calcium sulphate pellets were used in cavitary defects in 38 procedures in 34 patients with bone tumours. In 29 calcium sulphate pellets were used alone, in 8 allograft and in 1 autograft bone was added. The diagnosis was unicameral bone cyst in 13, giant cell tumour in 11, non-ossifying fibroma in 2, chondroblastoma in 2, benign fibrous histiocytoma in 2 and another pathology in 8 procedures. The femur was involved in 12 procedures, the humerus in 8, the radius in 5, the tibia in 4, the fibula in 3, the calcaneus in 2, and one procedure each in the tarsal cuboid, a metatarsal, the talus, and the middle phalanx of a finger.

Median follow up was 14 months (3 to 48). Seven patients had wound complications. Pellets had absorbed completely in 26/28 (93%) evaluable procedures by 3 months. Healing of the defect occurred in 24/28 (86%) evaluable procedures by 6 months. In 6 cases, the healed defect contained cystic areas simulating local recurrence. In 3 cases, there was collapse of the defect.

In cavitary defects, calcium sulphate pellets reliably absorb. Some patients have wound complications, especially where the cavity is relatively superficial. The pellets do not provide mechanical stability where there is attenuated cortical bone. Cysts within the healed defect may simulate recurrence.