There is evidence that various anatomical structures have altered morphology with ageing, and anecdotal evidence of changing lumbar spinous process (LSP) morphology with age. This study aims to clarify the influence of age on LSP morphology, and on lumbar spine alignment. 200 CT scans of the abdomen were reformatted with bone windows allowing precise measurement of LSP dimensions and lumbar lordosis. Observers were blinded to patient demographics. Inter-observer reliability was confirmed. The smallest LSP is at L5. The male LSP is on average 2-3mm higher and 1mm wider than the female LSP. LSP height increases significantly with age at every level in the lumbar spine (P<10-5 at L2). The LSPs increase in height by 2-5mm between 20-85 years of age (P<10-6), which was as much as 31% at L5 (P<10-8). Width increases proportionally more, by 3-4mm or greater than 50% at each lumbar level (P<10-11). Lumbar lordosis decreases in relation to increasing LSP height (P<10-4) but is independent of increasing LSP width (P=0.2). The height and width of the spinous processes increases with age. Increases in spinous process height are related to a loss of lumbar lordosis and may contribute to sagittal plane imbalance.
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.
