Auckland City Hospital, Auckland, New Zealand. To show that the spinous processes (SPs) increase in size with age. To investigate the incidence of SP abutment, relationship to disc degeneration and age related kyphosis. Describe patterns of SP neoarticulation in relation to back pain and intersegmental axial rotation and deformity. We reviewed 200 Abdominal CTs, CT myelograms and 100 standing x-rays (age 18-90 years). We measured SP size, interspinous gap, patterns of neoarticulation, disc height, lumbar lordosis and axial rotation. We compared symptomatic and asymptomatic groups. A 30-50% increase in SP size coupled combined with a loss of disc height leads to increasing rates of SP abutment after the age of 35 years. 30% of people over the age of 60 years have SP abutment. There is a 15 degree increase in standing lumbar kyphosis with age. Four patterns of SP neoarticulation are seen. Degenerative changes in the SP articulation increase by more than 80% in a symptomatic cohort. Oblique SP articulation is 2.5 times more likely in symptomatic individuals and associated with a rotational intersegmental deformity. Ageing is accompanied by SP enlargement and abutment, contributing to a loss of lumbar lordosis. Patterns of neoarticulation and degeneration appear associated with back pain and rotational deformity.
