A system of surgical instruments for use with a first implant type and a second implant type, wherein the first implant type is a different type from the second implant type, the system comprising at least: a first container and a second container, each one of the first container and the second container containing at least a first surgical instrument of a first type that is size specific and a second surgical instrument of a second type that is size specific, wherein both the first surgical instrument of a first type and the second instrument of a second type are of the same size and for use with the first implant type, wherein the size of the first surgical instrument of a first type and the second surgical instrument of a second type contained in the first container is different from the size of the first surgical instrument of a first type and the second surgical instrument of a second type contained in the second container; a third container and a fourth container, each one of the third container and the fourth container containing at least a third surgical instrument of a third type and a fourth surgical instrument of a fourth type, wherein both the third surgical instrument of a third type and the fourth surgical instrument of a fourth type are of the same size and for use with the second implant type, wherein the size of the third surgical instrument of a third type and the fourth surgical instrument of a fourth type contained in the third container is different from the size of the third surgical instrument of a third type and fourth surgical instrument of a fourth type contained in the fourth container; and a fifth container containing a first surgical instrument of a fifth type and a second surgical instrument of a fifth type which is independent of the size of the implants; wherein the first surgical instrument of the fifth type is for determining the required size of the first implant type and the second implant type so that the size of the first surgical instrument of a first type and the second surgical instrument of the second type can be determined and so that only the correct one of the first or second container is selected; wherein the second surgical instruments of the fifth type is for determining the required size of the first implant type and the second implant type so that the size of the third surgical instrument of a third type and the fourth surgical instrument of the fourth type can be determined so that only the correct one of the third or fourth container is selected; and wherein the surgical instruments are sterilised within the containers. a first container and a second container, each one of the first container and the second container containing at least a first surgical instrument of a first type that is size specific and a second surgical instrument of a second type that is size specific, wherein both the first surgical instrument of a first type and the second instrument of a second type are of the same size and for use with the first implant type, wherein the size of the first surgical instrument of a first type and the second surgical instrument of a second type contained in the first container is different from the size of the first surgical instrument of a first type and the second surgical instrument of a second type contained in the second container; a third container and a fourth container, each one of the third container and the fourth container containing at least a third surgical instrument of a third type and a fourth surgical instrument of a fourth type, wherein both the third surgical instrument of a third type and the fourth surgical instrument of a fourth type are of the same size and for use with the second implant type, wherein the size of the third surgical instrument of a third type and the fourth surgical instrument of a fourth type contained in the third container is different from the size of the third surgical instrument of a third type and fourth surgical instrument of a fourth type contained in the fourth container; and a fifth container containing a first surgical instrument of a fifth type and a second surgical instrument of a fifth type which is independent of the size of the implants; wherein the first surgical instrument of the fifth type is for determining the required size of the first implant type and the second implant type so that the size of the first surgical instrument of a first type and the second surgical instrument of the second type can be determined and so that only the correct one of the first or second container is selected; wherein the second surgical instruments of the fifth type is for determining the required size of the first implant type and the second implant type so that the size of the third surgical instrument of a third type and the fourth surgical instrument of the fourth type can be determined so that only the correct one of the third or fourth container is selected; and wherein the surgical instruments are sterilised within the containers.