Officials would not allow the Albury rider to continue to compete beyond Stage 5 of the event, his second Dakar campaign, due to concern over his condition.
Houlihan had begun to feel pain as a result of a jolting blow from a hole, after which the drama became apparent, as he explained in his latest diary entry for Speedcafe.com.
Now, the extent of the fractures has been revealed by way of an x-ray, which he posted on Facebook.
The Australian finished 50th on debut last year, when he carried a broken scaphoid through most of the event.
After the rest day, Stage 7 takes place on Sunday (local time).