When Maddison had bone cancer (fibrosarcoma) amputation wasn't an option due to the location of the tumour. We let him do what he wanted to do. It is, as has been said, a case of balancing the risk against the pleasure they get and as Maddison was a four year old, otherwise 'healthy' boy, we knew it would be wrong (for him) to limit what he did so we let him run and we held our breath. Ironically, on the final night, he hurt his leg just by changing position on the settee.
Best wishes to you and to Lewis