Fatty Infiltration in Multifidus Muscles and its Association With Spinal MRI Findings

The present cross sectional study was conducted to evaluate the relation between fatty infiltration (FI) in multifidus muscles and spinal MRI findings among patients who referred to Sina Athar and Kosar imaging centers of Shahid Beheshti University of Medical Sciences

Discovertebral and facet joint degenerative changes, intervertebral foraminal narrowing, disk herniation and central canal stenosis in all lumbar levels and FI in multifidus muscles at the level of L5 vertebra were assessed on magnetic resonance imaging (MRI) studies of 333 patients, and correlation of these MRI changes with FI was identified.

Among 333 patients (174 female), whose data were analyzed, 316 patients mentioned a positive history of back pain. We observed a significant relation between female sex and higher age with degrees of multifidus FI in L5 level. No significant association was found between the existence of back pain and the rate of multifidus FI. There was a significant negative relation between the activity level and the amount of multifidus FI. Considering weekly exercise level and hours of computer use, this association was not observed. Evaluating the relation between end plate and facet joint degenerative process and also neuroforaminal stenosis with multifidus FI, a statistically significant relation was noted. This correlation was not observed for central canal stenosis.

We concluded that the degree of multifidus FI was remarkably higher in female gender, older ages and subjects with more sedentary lifestyle. Moreover, a significant correlation existed between abnormal MRI imaging findings (degenerative process, discopathies, foraminal stenosis) and multifidus FI.