De Medicina

21 It is very well known that the knee is put out externally and internally and backwards. Many have written that it does not slip out forwards; and this may be very near the truth, for the knee-cap

is there right in front and holds the head of the tibia in place. Meges, however, has recorded a case in which he replaced a knee which had slipped forwards. In cases affecting the knee-joint the sinews can be extended by the same means as I have described for the thigh. And when it has slipped out backwards, as described above, a round ball of some kind is placed on the ham, and when the leg is bent up over it, the knee slips back again. In the other cases it is to be replaced by the surgeon's hands while the bones are being drawn apart in opposite directions.