The material that encloses the silicone gel is quite strong. It would take a severe impact to the implant for it to rupture. Also see the link below for more information on Butt Implants.
Can Cohesive Silicone Butt Implant Leak or Break?
Doctor Answers (4)
Butt Implants Rupturing or Breaking
Butt implants should not rupture or break, as these are solid but not fragile. Kenneth Hughes, MD Los Angeles, CA
Can Silicone Butt Implants break or leak?
The buttock implants available in the United States are made of a solid silicone polymer. Even if the implants are punctured or cut, they will not leak or break. Best wishes.