A tendon serves to move the bone or structure. A ligament is a fibrous connective tissue that attaches bone to bone, and usually serves to hold structures together and keep them stable
If the boil ruptures under the skin, inflammation and infection spread quickly and new lumps form nearby. HS is a progressive disease so it is bound to get worse over time. It can be unpredictable. It is different for every person so it can be hard to predict.