HYPOTHESIS: The incidence of silicone breast implant rupture varies with implantation time and type of implant.

OBJECTIVE: To measure the incidence of implant rupture by repeated magnetic resonance imaging (MRI) among women with silicone breast implants.

DESIGN, SETTING, AND PARTICIPANTS: In 1999, 271 women who had received breast implants at least 3 years before, and who were randomly chosen from a larger cohort of women with cosmetic breast implants, underwent a baseline MRI. A second MRI was performed in 2001; 317 silicone implants (in 186 women) that were intact at the baseline MRI (n = 280) or were intact at baseline but removed before the second MRI (n = 37) were included in the rupture incidence analyses.

MAIN OUTCOME MEASURES: Implants were diagnosed with definite or possible rupture. Crude and implant age-adjusted incidence rates were calculated, and implant survival was estimated based on the observed rupture rates.

RESULTS: We found 33 definite ruptures (10%) and 23 possible ruptures (7%) during the 2-year period. The overall rupture incidence rate for definite ruptures was 5.3 ruptures/100 implants per year (95% confidence interval, 4.0-7.0). The rupture rate increased significantly with increasing implant age. Double-lumen implants were associated with substantially lower rupture risk than single-lumen implants. For modern implants intact 3 years after implantation, we estimated rupture-free survival of 98% at 5 years and 83% to 85% at 10 years.

CONCLUSIONS: The risk of implant rupture increases with implant age. A minimum of 15% of modern implants can be expected to rupture between the third and tenth year after implantation.