how can I fix finger bone rotate?

<- sorry about image size
the finger bones are broken start from the original game bones… (sorry my bad english xP)
how can I fix it? I dont know how to re rigging.
just I want to know how to fix the bone rotate in 3d max.
please help meeeee

Under skin modifier, in the advanced parameters roll out, uncheck the checkbox that says ‘Always Deform’. Now you can move the bones and alter them without affecting the mesh, simply rotate the finger bones to match the axes of ValveBiped fingers so finger poser moves them correctly. Then when you’ve got it corrected, recheck always deform to have the mesh move with the bones again.