An update on breast animation deformity grading systems — a systematic review

Background: Breast animation deformity (BAD) is a motion deformity resulting in displacement of the implant and skin rippling with pectoralis contraction. Animation deformity has recently gained more attention in the literature, however its prevalence and grading has yet to be established. The objective of this study was to systematically assess the existing grading systems of BAD, and the quality of grading systems. Methods: A systematic literature search was conducted according to PRISMA Guidelines in PubMed, EMBASE Ovid, EMBASE Classic (OVID), and Cochrane Database of Systematic Reviews. The review was registered in PROSPERO with registration number CRD42021223940. For all eligible studies, we evaluated the methodological quality of the studies. Results: Out of 1,297 studies, a total of 13 studies were retrieved assessing grading systems of animation deformity. Nine grading systems exists in the literature. The prevalence of animation deformity was 73.3% in total, 73.9% of patients with subpectoral implants experienced some degree of animation deformity, in contrast to prepectoral implants where 10.5% experienced some degree of animation deformity. Conclusions: There is great variability in the present literature regarding quality, reproducibility and validity of the grading systems, as well as the prevalence of animation deformity. We recommend two new grading systems, the qualitative Nipple, Surrounding Skin, Entire Breast (NSE) grading scale and Kim et al.’s quantitative grading system—two high quality, reproducible and clinically-relevant assessment methods. The evidence is still inadequate in the existing studies and more studies are needed where the new grading systems are being used for future comparative studies, especially randomized-controlled studies.