The purpose of this study was to establish the relationship between the anterior and posterior spinal elements and identify which morphological changes in the ageing spine has the greatest influence in determining the loss of lumbar lordosis. 224 patients' (98 male, 126 female) erect plain lumbar radiographs were reviewed. Lateral plane projections were used to measure the lumbar angle (lordosis), spinous process (SP) height, the interspinous gap (ISG) height, the mid-vertebral body (MVB) height and the mid inter-vertebral disc (MIVD) height of vertebral bodies L1 to L5. The relationship between the heights of these structures and their relative influence and effect on the lumbar angle was investigated using a multiple linear regression model. SP, ISG, MVB and MIVD heights all had a statistically significant influence on determining the lumbar angle (p < 10−3). All heights decreased with age except for the SP height (Graph 1). Age was associated with a decreasing lumbar angle (p 0.134) – (Graph 2). Increasing SP height had an inverse relationship on the lumbar angle. The increase in the SP height had the greatest influence on the lumbar angle (Beta coefficient of -0.71), whilst the MVB and MIVD heights had a lesser influence on determining the lumbar angle (Beta coefficients 0.29 and 0.53 respectively).Method
Results
