finally find it!
The reason why "Osteoporosis drugs help fight AS !? "

https://www.spondylitis.org/About-Spondy...s/Sept-Oct-2004


"Expanding The Therapeutic Horizon In Ankylosing Spondylitis
Osteoporosis is a readily preventable complication of AS"

By Dr. Walter P. Maksymowych

Dr. Walter P. Maksymowych--the inventor of "pulse intravenous pamidronate therapy for AS"