OBJECTIVE: To assess the effect of advancing age upon the development of lumbar spine degenerative arthritis in rhesus monkeys and the use of a custom central region of interest to minimize the impact of this process upon the bone mineral density as measured by DXA. RESULTS The prevalence of degenerative spinal arthritis dramatically increases at age 19 in female rhesus monkeys. Utiliziation of our custom central region of interest analysis program allows demonstration of ovariectomy induced bone loss with comparable sensitivity as standard analysis and does demonstrate an age-related decline in lumbar spine bone mineral density. FUTURE DIRECTIONS Application of similar custom region of interest analysis programs to human clinical DXA scans to assess if this improves the diagnostic sensitivity by excluding the spurious elevation of BMD due to degenerative spinal arthritis. KEY WORDS Osteoporosis, age-related, bone density