I had subcutaneous stitches pop at 6 weeks and Nurse “trimmed” it warning me it may surface again.
You may have seen this stitch as a subcutaneous level but it's clearly
not a subcutaneous stitch, it's a deep one. in this image, the level marked 'fat' is subcutaneous, between the two levels of fat - yellow is subcuticular and green and deep.
I would image your stitch is coming from the muscle layer and that the knot is gradually unwinding and emerging from your leg bit by bit. It might seem obvious then, to pull the material out which is fine if the winding of the knot is all undone but if it's not, then it might not be that easy to pull it out. And the material is rough surfaced which would complicate that. Also after 4 months, it's probably partially dissolved and therefore enmeshed in the tissues. In light of that, I'd just live with it for as long as it takes, get yourself a nice small and sharp pair of scissors (off Ebay?!) and clean them with any soap and hot water and snip it yourself. It's not difficult to do. Cleanse the area with disinfectant before and after as well.
My first surgeon’s glue job used nothing but glue.
He wouldn't have done that. The internal areas would be stitched up as normal and just the skin would be glued.
Second one put external stitches that need to be removed at top and bottom of incision and I wondered why that was as he said he also glued the incision post op.
This surgeon would have used what we call a subcuticular stitch which is run
just below the level of the skin and secure with a knot as each end. Some surgeons do then apply Dermabond surgical glue to the skin edges as well but it's not really necessary. Here's my subcuticular stitch I had on my arm but instead of running the suture just under the skin, he looped it from side to side in what we call an internal mattress stitch! Below is the stitch after it was removed!