Sub-Pectoral Implant

The pectoralis major muscle has a very broad origin, from the clavicle, sternum, and upper seven costal cartilages and ribs; it sweeps to the arm with a narrowing muscle bulk, converging on the tendon which inserts into the humerus.

In the sub-pectoral (also called retro pectoral) breast implant, the prosthesis is inserted and fixed deep to the pectoralis major muscle, but the position of the breast in front of this muscle does not completely overlap it. Hence when the implant is aligned with the breast, as it must be, it is only about half to two thirds covered by pectoralis major.

This choice of implant position is likely to be selected for the woman with rather slight breasts, who is not used to breast movement and does not expect it.

Some surgeons will modify this with submuscular implantation, covering the lower “exposed” portion of the prosthesis with the serratus anterior muscle which has laterally directed slips arising from the approximate midpoint of the upper eight ribs; coverage may also be supplemented with the deep fascia from the rectus abdominis muscle.