deep fascia n.
A thin fibrous membrane forming an intricate network that envelops and separates muscles, forms sheaths for nerves and vessels, forms or strengthens ligaments around joints, envelops various organs and glands, and binds all structures together into a firm compact mass.
Drawing the latter aside, cautiously divide the deep fascia.
It is more likely to occur if the deep fascia has been imperfectly divided before carrying out the dissection to the inner side.
The deep fascia must be exposed and opened, and the muscles relaxed and held aside.