The osteosarcoma amputation stump: a clinico-radiographical correlation.

The radiological picture of the amputation stump after osteosarcoma was reviewed in 75 cases, in which postoperative follow-up ranged from a minimum four months, to a maximum of over 12 years. In 67/75 cases (89%) no recurrence was observed; in 8/75 cases (11%) a local neoplastic recurrency was confirmed on clinical and histopathological grounds. The usual aspects of late modifications induced by surgery include osteoporosis of the residual bone, which may assume a geographical pattern, with thinning of the stump apex and formation of a periosteal spur directed towards the soft tissues. The typical pattern of locally recurrent osteosarcoma is that of an infiltrating soft tissue mass with bone erosion and irregular flake-like calcifications. All these signs are presented and discussed in order to give a practical guideline to the differential diagnosis between surgery-induced modifications and local neoplastic recurrences.