The ornamental design for a medicalappliance, as shown and described.
FIG. 1 is a perspective view of a medical appliance of the present design;
FIG. 2 is a top view thereof;
FIG. 3 is a bottom view thereof;
FIG. 4 is a first side view thereof;
FIG. 5 is a second side view thereof;
FIG. 6 is a third side view thereof;
FIG. 7 is a fourth side view thereof; and,
FIG. 8 is a perspective view thereof positioned around a body part.
The broken lines showing a body part in FIG. 8 depict environmental subject matter, and all other broken lines depicted portions of the medical appliance that form no part of the claimed design. The broken lines form no part of the claimed design.