Association between Trunk Muscle Mass and Progression of Vertebral Collapse in Patients Treated Conservatively for Vertebral Compression Fractures.

Objectives: This study aimed to determine the relationship between trunk muscle mass and progression of vertebral collapse in elderly patients treated conservatively for vertebral compression fractures.

Methods: This retrospective study was conducted in a convalescent ward and included 104 patients (36 men, 68 women; mean age: 83.8 years, minimum age: 65 years) with vertebral compression fractures. Using the semi-quantitative (SQ) method, patients were divided into two groups: the vertebral collapse group (SQ grade increased by at least 1 from admission to discharge) and the vertebral non-collapse group (no change in SQ grade from admission to discharge). The following data were retrieved from medical records: age at admission, sex, fracture site, Charlson Comorbidity Index, Appendicular Skeletal Muscle Mass Index, Trunk Muscle Mass Index (TMI), bone mineral content, Mini Nutritional Assessment-Short Form (MNA-SF), and Sagittal Vertical Axis (SVA) change. Intergroup and logistic regression analyses were performed to evaluate factors associated with the progression of vertebral collapse.

Results: Comparison between the vertebral collapse group and the non-collapse group showed significant difference in TMI (6.2±0.9 kg/m² vs. 5.5±0.6 kg/m², P<0.01), MNA-SF (9.4±1.8 vs. 8±2.1, P<0.01), and SVA change (0.3±0.2 cm vs. 0.7±0.3 cm, P<0.01). Logistic regression analysis showed that TMI was significantly associated with progression to vertebral collapse, regardless of sex [men, odds ratio (OR): 0.26, 95% confidence interval (CI): 0.06-0.73, P<0.05; women, OR: 0.32, 95% CI: 0.12-0.71, P<0.05].

Conclusions: Trunk muscle mass was associated with the progression of vertebral collapse in patients receiving conservative treatment for vertebral compression fractures.