Low Earth Orbit (LEO) satellite networks are well characterized by frequent and bursty handover occurrences, and these handovers largely affect the cost of mobility management in LEO satellite networks. Although geographical location of a mobile node is useful information to make the mobility management independent from handovers, it is difficult to decide a last-hop satellite of the node based only on geographical location information. This last-hop ambiguity problem needs additional cost to find the real last-hop satellite. To reduce last-hop ambiguity, we propose to exploit orbital information of the satellite connected with a destination node in addition to geographical location information. Simulation results shows that the number of last-hop candidates and hop counts between candidates are reduced by introducing orbital information. Through a mathematical analysis, we evaluate the cost required for mobility management and show the effectiveness of the proposed method.