The glossary of the Catechism of the Catholic Church defines reparation as the act of “making amends for a wrong done or for an offense, especially for sin, which is an offense against God.” The penance that the priest gives in confession is an example of this sort of act.
Redemptive suffering refers to our sufferings we offer up to Jesus for the salvation of souls, whether our own or others. Such an offering can be specifically directed to making amends for our own sins or those of others. But it doesn’t have to be. One could offer one’s suffering for other reasons.
So, not all acts of reparation are acts of redemptive suffering, nor are all acts of redemptive suffering acts of reparation. But acts of redemptive suffering can be acts of reparation.