Are you certified? Through which organization?
          There is one national Certification Board: American Board for Certification and some states  provide  State licensure of which Texas is one of those states.
How many patients with a [insert your amputation level] amputation have you fit?
          The answer should give you an idea of the amount of experience offered for your needs.           
What’s the age range and activity of your patients?
        A prosthtist that only sees older patients will not know the needs of childrens growth or high competion athletics. A prsothrtis that does see only younger population may not be concerned with ease of use or complicated setups that frustrate older patients.
 On average, how many patients do you work with per year?
          Most prosthetists know the caseload they manage each year. Under 50 per year is acceptable in a small community.  Over 200 may mean that the prostetist might not see all the details you need considered.
Do you see taking care of prosthetic needs as a team approach where I as the patient, my doctor,my therapist and you as my prosthetist work together?
        Gettng input from all of the caregivers involved can greatly add to your success