In vivo growth and progression of chondrosarcoma cell lines. a) This graph plots the injected to non-injected limb volume ratios for the study groups at each time point. Periosteal injected JJ012 developed into tumours most rapidly, followed 2-3 weeks later by intratibial injected JJ012. FS090 did not form tumours in either implantation site. b) Periosteal tumours expanded one area of the limb while intratibial tumours grew in a circumferential manner. On histology both tumours (T) invaded cortex, but leaving the epiphysis (E) largely intact. On radiographs, lytic regions (black arrow), and sclerotic (grey arrow) were noted in both models. c) 5/5 animals injected with periosteal JJ012 demonstrated lung metastases, in contrast with 2/4 animals in the intratibial group. d) Lung metastases (M) were lobular in appearance, and were positive on Alizarin red staining (arrows), indicating calcification.