How did you fertilize? Generally the recommendation for fertilization for orchids is weakly weekly.

Those look like old dendrobium canes to me. It's normal for old canes to lose their leaves and slowly shrivel up. You'll know if your culture is good if you see a new growth this spring/summer.

Here's a culture sheet for more info http://www.aos.org/orchids/culture-sheets/dendrobium.aspx