The Prevalence of Lumbar Paraspinal Muscle Fatty Degeneration in Patients with Modic Type I and I/II End Plate Changes

STUDY DESIGN: Retrospective case control. PURPOSE: The authors of this study assessed whether the prevalence of paraspinal fatty degeneration correlates with the presence of Modic type I and I/II change in patients with low back pain (LBP). OVERVIEW OF LITERATURE: Modic changes are bone marrow and end plate changes visible on magnetic resonance imaging. METHODS: A consecutive series of 141 patients who attended the neurosurgery outpatient clinic between April 2017 and September 2017 for nonspecific LBP were evaluated. Sixty-one patients with single-level Modic type I or I/II change constituted the patient group. Eighty age-, gender-, and body mass index (BMI)-matched patients without any Modic changes were recruited as the control group. A retrospective review was performed in 61 patients with Modic changes and 80 controls without Modic changes. The percentage of fatty muscle degeneration was graded by two reviewers using T2-weighted axial images at the L4–L5 level. The system was graded as follows: grade 0, normal; grade I, minimal focal or linear fat deposition; grade II, up to 25%; grade III, 25%–50%; and grade IV, more than 50%. RESULTS: Sixty-one patients with nonspecific LBP and Modic type I or I/II change and 80 patients without Modic changes were evaluated. There was no difference between these groups in terms of age, gender, and BMI distribution. The mean muscle cross-sectional area in the patient and control groups were 1,507.37±410.63 and 1,681.64±379.69. Regarding fatty degeneration, a chi-square test of homogeneity was run, and the two multinomial probability distributions were not equal within the population analyzed. CONCLUSIONS: The novel finding of this investigation is that patients with Modic type I and I/II changes have greater amounts of fatty degeneration in their lumbar paraspinal musculature.