Abstract
Two hundred and forty-eight high-grade central osteosarcomata were treated by amputation or disarticulation; in 5.2 per cent the tumour recurred at the amputation site. The following causes may be responsible for local recurrence: the level of the amputation is too close to the tumour; there is an unrecognised intramedullary extension of the tumour; during a previous block resection tumour cells may have been seeded in the soft tissues; the primary tumour was too extensive even for radical surgery; "skip" metastases may have been present; iatrogenic tumour implantation may have occurred while a biopsy was being performed during the course of an amputation. Treatment of the primary osteosarcoma should take all these possibilities into account. In our experience adjuvant chemotherapy has not significantly changed the frequency of local recurrences which should be treated by radical operation or, if this is not possible, by irradiation; chemotherapy may be used as an adjuvant. The prognosis of local recurrences is bad.