What is Animation Deformity?

When looking into a breast reconstruction procedure, an important question to consider is in which position you would like your implants to be placed. If you choose a pre-pectoral positioning, your implant will be placed above your pectoralis muscle. On the other hand, if you choose a subpectoral positioning, your implant will be placed below your pectoralis muscle. There are pros and cons for both of these approaches, therefore this decision ultimately comes down to what is best for each specific patient.

This differing pre-pectoral versus subpectoral placement leads to various affects in appearance and comfort level. The subpectoral positioning of the breast implant may often protect against infection or capsular contracture, yet in some of these cases we observe a shift in the implant upon contraction of the chest muscle. When the pectoralis muscle is engaged, such as during exercise, the implant can shift in the breast—a phenomenon now referred to as animation deformity, or breast distortion.

Although previous studies have confirmed that animation deformity is indeed occurring in a number of these subpectoral implant patients, there is an overall lack of available information or published work on this topic. Dr. John Kim, at Northwestern Medical Group, is leading a study addressing some of these unanswered questions regarding animation deformity.  Dr. Kim is interested in understanding the number of patients affected by this breast distortion, as well as in determining if there is a correlation between the implant movement and the pain experienced by the individual. Through this study, he hopes to learn more about animation deformity and why this is occurring in only some of his subpectoral breast reconstruction patients.