No, maybe I'm not describing the process right, but it's different. Two things that are different is that you can join any lengths, the surgeons, I believe, requires you pull one line through and both are wrapped together. I'm not familiar with the J, but in looking at it it appears different. The knot I'm suggesting can be tied into any length of line and when the tags are wrapped through the loop in opposite directions you get a nice round, balanced knot, very similar to a double uni. I think it's easier to tie than a double uni.