Modic changes and high intensity zones commonly co-exist in spinal segments in chronic low back pain patients but are not evidently related to patient reported pain (#1042)
Intruduction
Low back pain (LBP) has been suggested to be associated to Modic changes (MC) and high intensity zones (HIZ), displayed on conventional magnetic resonance images. In a previous feasibility study, it was shown that patients with chronic LBP frequently display a simultaneous presence of MC and HIZ in the same motion segment [1]. We hypothesized that a simultaneous presence of MC and HIZ in the same motion segment has a stronger association to back pain than the presence of MC only.
The aim of this study was to relate MRI findings to patient-reported back pain in a prospective cohort of patients with chronic LBP.
Methods
The lumbar spine of 100 chronic LBP patients (age: 43±9 years; 66 males), which had experienced >6 consecutive months with LBP, were examined with MRI (Table 1). All patients rated their back pain during the last week using a Numeric Rating Scale (NRS), 0-10, before the MRI. MCs according to Modic et. al [2] were typed on sagittal T1- and T2-weighted MR images by a senior radiologist. For mixed types, the dominant type (>50%) was chosen. Patients that displayed MCs, with an affected region of at least 25% of the vertebral body, visible on at least two consecutive MR image slices were included as having a MC. The radiologist evaluated all discs in segments having MCs regarding the presence of HIZ (high signal in the annulus fibrosus, clearly separated from nucleus [3]) or not using T2-weighted images. The independent t-test, adjusted for multiple testing, was used for group comparisons. Mixed effects models, accounting for multiple measurements per subject, were used to estimate least squares mean and Tukey’s range tests were used to test differences in least squares mean between groups.
Results
Out of the 100 LBP patients, 42 patients (23 males; age: 47±10 years) had MCs localized in 88 vertebrae, corresponding to 2 MCs per patient. HIZ were frequently displayed in the adjacent discs (n=32/35, 91%). 50% of the HIZs were adjacent to vertebrae with MC type 1, 40% adjacent to type 2 while none was found adjacent to type 3.
Patients that displayed a simultaneous presence of MC and HIZ in at least one motion segment did not report significantly higher pain scores than patients with only MC findings (NRS:5.7±2.1 vs 6.7±1.9; p=0.09), neither when stratifying for Modic type. Moreover, no significant association was found between NRS and the presence of any MC, neither for all MCs stratified for MC type.
Discussion
This work confirms previous findings of that HIZ is commonly present within the same motion segment as MCs. However, chronic LBP patients with both MC and HIZ in the same motion segment did not report significantly higher back pain on NRS than those with only MC findings or no MC findings. Since pain is a subjective experience, the lack of association here does not necessarily imply that MC and HIZ do not play a role in chronic LBP, however the findings does not support these as direct pain imaging biomarkers.
- 1. Lagerstrand, K., Brisby, H.,Hebelka, H. (2021) Associations between high-intensity zones, endplate, and Modic changes and their effect on T2-mapping with and without spinal load. Journal of Orthopaedic Research. 2. Modic, M. T., Steinberg, P. M., Ross, J. S., Masaryk, T. J.,Carter, J. R. (1988) Degenerative disk disease: assessment of changes in vertebral body marrow with MR imaging. Radiology 166:193-199. 3. Aprill, C.,Bogduk, N. (1992) High-intensity zone: a diagnostic sign of painful lumbar disc on magnetic resonance imaging. Br J Radiol 65:361-369.
