It is hard to tell from the photo you provided, but I would say that a few weeks of debridement and wound care and then maybe you can either have a secondary closure procedure or it will take time to heal secondarily which would be about 4-6 weeks by the size of the wound.
Sorry for the wound necrosis. Most case in the amount of necrosis takes a few months to heal completely...You should be seeing 3-d shrinkage of the deformity.
Thank you for your pictures. The percentage of in healthy individuals in my opinion and in my practice is definitely less than 20%. It's probably less than 5%. Sounds like a surgeon is doing all the right things. You can tell if it's healing when the measurements continue to get smaller.
20% is a very high percentage. There are ways to get the risk well under 1%. In either case, once the wound is there, it will need proper care to keep it clean and allow it to heal. Expect it to take about 6 weeks. You will know it is healing as the tissue becomes all pink throughout, which it will with dressing changes and a little wound care. Then it will gradually fill in and close. The scar may or may not require a revision once it is completely healed. Good luck.