A surgical stapling apparatus includes a housing and an end effector secured to the housing. The housing supports a knife assembly including a knife. The end effector has first and second jaw members. One or both of the first and second jaw members define a knife channel. The first jaw member defines fastener slots and the second jaw member defines fastener pockets. One or more of the knife channel, the fastener slots, and the fastener pockets includes lateral recesses. Fasteners are disposed in the fastener slots and formed by the fastener pockets. One or more surgical buttresses have a body that overlies one or both of the fastener slots and the fastener pockets. Portions of the body of the one or more surgical buttresses are disposed within the lateral recesses to secure the one or more surgical buttresses to one or both of the first jaw member and the second jaw member.