how long does it takes to get an appointment with the orthopedic department at this hospital

Ortho is at the main campus on Lancaster in Dallas.

Depends on the availability of the doc. If you can't get an appointment within 30 days, defer to the choice program if it's dire. If it's not dire, wait for the appointment at a VA facility. Choice refers you to outside the VA facility, but you're likely not getting the 'best' care. VA care, in my opinion, is better than choice care. That's not saying VA care is optimal.