can you tell me where you are located?
if there is a Dorn Method Practitioner in your area then its definitely worth to give it a try.
To be able to give some form of long distance help I need to know more about the condition, e.g. exact diagnosis, MRI, x-ray tests etc.
things i can recommend for now: no stretching please, massage the buttocks muscles several times a day for approx. one minute at a time. if he can let him try the exercises i feature in my website: http://www.dorn-method.com
you also find a practitioners listing there.