Deep muscular abscess in upper back (15 cm on USG)

I have a deep muscular abscess in the left upper back/neck–shoulder blade area. Ultrasound shows a fluid collection in the muscle plane with tracking reported up to ~15 cm. Clinically, pain is mainly at one spot. Pus culture grew Staphylococcus sensitive to antibiotics; I’m currently on IV antibiotics. I’d like clarification on whether this usually represents one main pocket with tracking, the typical number/size of incisions needed, and the risk of recurrence after proper drainage.