Answer :
In "A Separate Peace" Finny's "shattered" leg symbolizes the shattered or broken friendship of Gene and Finny. The two friends are no longer comfortable in each other's presence. Their trust, which was always very fragile, is now completely broken.
Finny is not able to come to terms with the fact that his friend deliberately made him fall off from the tree and shattered his dreams of becoming an athlete forever. Their friendship is now completely shattered and hopeless.
