An ultrasound medical system includes an ultrasound end effector. The ultrasound end effector has an exterior surface, includes a medical ultrasound transducer assembly having at least one medical-treatment ultrasound transducer, and includes at least one tine. The at-least-one tine is deployable to extend away from the exterior surface into patient tissue to provide at least some stabilization of the ultrasound end effector with respect to patient tissue and is retrievable to retract back toward the exterior surface.