Characteristics of fat infiltration in the lumbar trunk muscles in elderly female patients with lumbar compression fracture.

Abstract

The aim of this study was to examine the fat infiltration ratio in the lumbar multifidus (LM), erector spinae muscles (ESM), and psoas major (PM) in elderly female patients with lumbar compression fracture. Subjects were fourteen elderly females aged 65 or over who have been diagnosed with lumbar compression fracture. A total of 11 levels per individual, corresponding to the axial sectional planes through the upper endplate and middle endplate of each lumbar vertebra (L) and the upper margin of the first sacral vertebra (S), were measured LM, ESM, and PM cross-sectional area (CSA). The images were transferred to the Image J. The fat infiltration ratio was a value obtained by dividing the fat infiltration area at CSA (muscle and fat). Range of the fat infiltration ratio in LM and ESM were 13.9~26.5%,and that of PM was 0.4~2.0%.The fat infiltration ratioinLMand ESM were significant higher than that of PM (p<0.01~0.001). The fat infiltration ratio of each muscle did not demonstrate significant correlations with body mass index. There were no significant differences in the fat infiltration ratio of 11 levels inthesamemuscle. The difference in fat infiltration ratio were compared by classifying the fracture and non­ fracture. There were no significant differences in the mean, the left and the right in both each muscles. These results suggested that LM and ESM fat infiltration rateinpatients with lumbar compression fracture of this study was observed as a whole rather than a focal fatty infiltration.