I've taken wound vac classes to become more knowledgeable on the functions of how and why they're used. This situation, to me, sounds very odd. I work with a lot of wound vacs and have NeVer seen one used on top of sutures. What is the purpose of putting it on top of the sutured wound, I don't understand.
I used to think that wound vacs were for just draining the wounds, but they have another function, along with removing infectious material from the wound, they help draw wound edges together and promote granulation at the cellular level thereby decreasing the time for wound healing.
Where I work, the doc will open up an infected wound, place the wound vac sponge or sponges inside the wound. Sometimes more than one sponge has to be used, so it's very important that whoever puts these vacs in must document accurately how many sponges are used. During my wound vac class, we were told that improper documentation has occured, ie....someone with a tunneling wound had sponges placed inside, this part of teh wound was healing and when the vac was changed the sponge wasn't seen very well and was left inside the wound. Needless to say, they had to go back in there and do it all over again.
Check out this website on wound vacs, it sounds like you may need to educate someone around there and advocate for this patient as much as you can. I also agree with the above post in that scans need to be done (if not already done) to rule out osteo.
Good luck with this situation.