A Muscular Etiology for Medial Implant Malposition Following Subpectoral Augmentation.

BACKGROUND Implant malposition is becoming an increasingly recognized complication following subpectoral breast augmentation. Although several causes of medial malposition have been previously demonstrated, medial implant malposition secondary to unintended pectoralis muscle slips has not been previously described. OBJECTIVE The goal of this study is to describe a form of medial implant malposition caused by pectoralis major and minor musculature vectors on the implant. METHODS The primary investigator performed a retrospective review of all patients who underwent revisional breast surgery for the diagnosis of symmastia or medial implant malposition following subpectoral augmentation. Those patients with muscular-type etiology for medial implant malposition were identified. RESULTS Five patients with pectoralis muscle slips causing medial implant malposition were identified. The pectoralis muscle slips were successfully diagnosed on preoperative exam and corrected with specific surgical procedures aimed at balancing surrounding forces and thus correcting malposition. CONCLUSIONS Pectoralis muscle slips contributing to medial malposition can be found in some patients after subpectoral breast augmentation. The etiology of this deformity is unknown, but theorized to be caused by anatomic predisposition, with slips inadvertently formed during subpectoral pocket formation arising from the pectoralis minor and/or incompletely released or accessory pectoralis major muscles.