The Influence Of Sex, Age, And BMI On The Degeneration Of The Lumbar Spine

Abstract

Osteophytes are degenerative bony outgrowths on joint margins and ligament attachment sites that may limit movement and cause pain. Previous research on the lumbar spine has relied on the use of one or two osteophyte scoring regions per vertebra and focused on the relation of age and sex to degeneration. The inclusion of body mass index (BMI) may result in a more complete consideration of possible contributing factors. Additionally, the use of a larger number of scoring regions would facilitate the analysis of more subtle variation. PURPOSE: This study investigates lumbar osteophyte development on the lamina and vertebral bodies to determine: 1) whether or not osteophyte development is related at different levels, right and left sides, and superior and inferior margins; 2) whether or not osteophyte development is correlated with age and/or BMI. METHODS: Seventy-six deceased individuals (39 females, 37 males) were randomly selected according to sex and age categories. Osteophyte development was scored in eight different regions on each lumbar vertebra at all five levels, for a total of 40 scores per individual. A factor analysis was performed in which all scoring regions were considered. Pearson's correlation analyses were performed to determine the relatedness of age and BMI with the consequent factors. Males and females were considered individually and then compared. RESULTS: The factor analysis separated the variables into three similar factors for males and females defined as: 1) superior and inferior vertebral body scores, 2) superior lamina scores higher in the vertebral column, and 3) inferior lamina scores lower in the vertebral column. For both males and females as age increased, the severity of vertebral body osteophytes increased. Additionally for females, as BMI increased, osteophyte severity increased for both the superior lamina margins higher in the column and the vertebral bodies. CONCLUSION: Dissimilarities between the factors in males and females provide evidence for different biomechanical processes influencing osteophyte development. The correlation of BMI to osteophyte severity exclusively in females further indicates biomechanical disparities between the sexes. More research with a larger sample size must be done to fully explain the nature of these relationships.