BACKGROUND: Capsular contracture is traditionally evaluated using the Baker classification. However, this classification has notable limitations in reproducibility and objectivity.

OBJECTIVES: To develop and validate procedure-specific histopathological scoring systems to assess capsular contracture severity.

METHODS: Biopsies of breast implant capsules were used to develop histopathological scoring systems for patients following breast augmentation and breast reconstruction. Ten histological parameters were evaluated using multivariable logistic regression to identify those most associated with capsular contracture. Significant parameters (p < 0.05) were selected for the scoring systems and assigned weighted scores (1-10). Validation was performed using area under the curve (AUC) and mean absolute error (MAE).

RESULTS: A total of 720 biopsies from 542 patients were included. Four parameters were selected for the augmentation scoring system including collagen layer thickness, fiber organization, inflammatory infiltration, and calcification, providing a combined maximum score of 26. The AUC and MAE for the augmentation scoring system was 81% and 0.8% which is considered strong. Three parameters were selected for the reconstruction scoring system including fiber organization, collagen layer cellularity, and inflammatory infiltration, providing a combined maximum score of 19. The AUC and MAE of the reconstruction scoring system was 72% and 7.1% which is considered good.

CONCLUSIONS: The new histopathological scoring systems provide an objective, reproducible, and accurate assessment of capsular contracture severity. We propose these novel scoring systems as a valuable tool for confirming the capsular contracture diagnosis in the clinical setting, for research, and for implant manufacturers and insurance providers in need of a confirmed capsular contracture diagnosis.