THE JOURNAL OF BONE AND JOINT SURGERY

Percutaneous needle biopsy was introduced 60 years ago (Coley, Sharp and Ellis 1931) but only more recently has it been used for the diagnosis of primary bone tumours. It is accurate, rapid, and is associated with fewer complications than open biopsy (Tilman et al 1979). Care is required because of the theoretical risk of recurrence in the track of a fine-needle biopsy. We report such a case. Case report. An 1 8-year-old man presented with a two-month history of progressive pain in the right knee, with recent swelling. He was otherwise fit and well, but examination showed a diffuse swelling, no effusion, and limitation of flexion to 100#{176}.There were small reactive lymph nodes in the right groin. Plain radiographs showed an osteoblastic lesion on the lateral distal condyle of the right femur (Fig. 1). Bone scanning and CT of the chest showed no metastatic disease, and a percutaneous needle biopsy was performed, using a Jamshidi needle through a lateral approach. The results confirmed the radiological dia-gnosis of an osteosarcoma, and the lesion was staged as IIB (Enneking, Spanier and Goodman 1980). Three courses ofadjuvant chemotherapy were given, using cis-platinum and adriamycin, before a right distal femoral massive replacement was performed through a midline approach with en bloc excision ofthe distal femur (Fig. 2). At the time of surgery the needle track was no