Here is a good link on splinting broken bones, and look at pages 19-23:
https://theiwrc.org/wp-content/uploads/2011/05/Duerr_Splinting_Manual_2010.pdf
Pictures of the injury might help.
https://theiwrc.org/wp-content/uploads/2011/05/Duerr_Splinting_Manual_2010.pdf
Pictures of the injury might help.