There are many potential causes for the pain. It could be capsular contracture, fibrosis, bony discomfort, axillary scarring, intercostial brachial cutaneous neuropathy, radiation changes, neuromas, etc. In my experience, the most common cause is a taut axillary scar that often is involved with a caspular contracture. Conversion of an implant to autologous tissue recosntruction may provide vascularized tissue that prevents recurrent capsular contracture but therre are many other alternatives which are less invasive albeit not as succesful. Occasionally, I have found that performing a z-plasty on the axillary scar can provide relief of discomfort caused by a tethered scar.