Fatty Degeneration of the Autochthonous Muscles Is Significantly Associated with Incidental Non-Traumatic Vertebral Body Fractures of the Lower Thoracic Spine in Elderly Patients

Purpose: We investigated loco-regional degenerative changes’ association with incidentally found non-traumatic vertebral body fractures of the lower thoracic and lumbar spine in older patients. Methods: The patient collective included patients in the age range of 50 to 90 years. Vertebral bodies from T7 to L5 were included. Vertebral body fractures were classified according to Genant. The following loco-regional osseous and extra-osseous degenerative changes were included: osteochondrosis, spondylarthritis, facet joint asymmetries, spondylolisthesis, scoliosis as well as fatty degeneration and asymmetry of the autochthonous back muscles. Patients with traumatic and tumor-related vertebral body fractures were excluded. Non-traumatic fractures of the lower thoracic and lumbar spine were evaluated separately. The Mann–Whitney U-test was used, and relative risks (RRs) were calculated for statistics. Pearson’s correlations (Rs) were used to correlate grades of degenerative changes and fracture severities. Results: 105 patients were included. Fatty deposits in the autochthonous muscles of the lower thoracic and the lumbar spine were associated with non-traumatic vertebral body fractures in the lower thoracic spine (p = 0.005, RR = 4.92). In contrast, muscle fatness of the autochthonous muscles was not a risk factor for lumbar spine fractures (p = 0.157, RR = 2.04). Additionally, we found a moderate correlation between fatty degeneration of the autochthonous muscles and the severity of fractures in the lower thoracic spine (RR = 0.34, p < 0.001). The other degenerative changes did not present any significant difference or correlation between the evaluated groups. Conclusions: Fatty degeneration of the autochthonous spinal musculature is associated with incidentally found non-traumatic fractures of the lower thoracic spine.