The ornamental design for a ladder hinge, as shown and described.
FIG. 1 is a perspective view of a ladder hinge showing my new design;
FIG. 2 is a right-side plan view thereof;
FIG. 3 is a left-side plan view thereof;
FIG. 4 is a front plan view thereof;
FIG. 5 is a rear plan view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof; and,
FIG. 8 is a perspective view of a ladder hinge shown in its application in a ladder as a reference.
The broken lines of FIGS. 1-7 illustrate portions of the ladder hinge that form no part of the claimed design. The broken lines of FIGS. 8 illustrate an environment of the ladder hinge as it may be used and form no part of the claimed design.