[Radiographic evaluation of the amputation stump in osteosarcoma].

The radiological picture of the amputation stump for osteosarcoma was revised on 57 cases, in which a follow-up after surgery was possible for at least 4 months, with a maximum of over 12 years. In 51/57 cases (89%) no recurrency was observed; in 6/57 cases (11%) a local neoplastic recurrency was confirmed on clinical and histopathological grounds. The usual aspects of late modifications induced by surgery is 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 to soft tissues. The typical pattern of the locally recurrent osteosarcoma is that of an infiltrating soft tissue mass with bone erosion and irregular flake-like calcifications. All these signs are evaluated and discussed in order to give a practical guideline to the differential diagnosis between surgery-induced modifications and local neoplastic recurrencies.