Predicting the Nonunion of the Acute Osteoporotic Vertebral Compression Fracture Following Low-Energy Injuries by Quantifying Vertebral Marrow Fat Fraction on T-Weighted Dixon Sequences.

OBJECTIVE

Increased marrow fat fraction (MFF) of vertebrae was detected in patients with osteoporosis. However, MFF of the fractured vertebrae decreased significantly following the fracture. The aim of this study was to assess the predictive value of fractured vertebrae MFF quantified on T-weighted Dixon sequences for the prediction of nonunion risk of acute OVCF.

MATERIALS AND METHODS

Medical records of 39 patients with OVCF, including a total of 60 fractured vertebrae, were reviewed retrospectively. Fractured vertebrae in the acute phase were grouped into the nonunion group (20 vertebrae) and the union group (40 vertebrae), based on the OVCF prognosis confirmed by computer tomography (CT). MFF of the fractured vertebrae was quantitatively assessed with the software Matlab on T-weighted Dixon sequences. Interclass correlation coefficients (ICC) were analyzed to assess the repeatability of MFF measurement. Binary logistic regression analysis was performed to determine the relative contribution of the MFF for predicting the prognosis of OVCF. Receiver operating characteristic (ROC) curve analysis was performed to determine the diagnostic performance of MFF.

RESULTS

The ICC indicated that the repeatability of MFF measurement was excellent (all p < 0.001). The MFF (42.25% ± 26.61%) decreased significantly compared to the value before OVCF (79.84% ± 9.65%) (p < 0.001). The MFF of the fractured vertebrae was lower in the nonunion group (16.40% ± 15.65%) than in the union group (55.18% ± 20.93%) (p < 0.001). Binary logistic regression analysis indicated that MFF of fractured vertebrae could independently predict the prognosis of acute OVCF (p < 0.001). ROC analysis indicated the area under the curve was 0.928 (95% CI, 0.831-0.979, p < 0.0001).

CONCLUSIONS

The MFF quantified on T-weighted Dixon sequences was a useful marker for assessing the nonunion risk of acute OVCF. The fractured vertebra with low MFF should be carefully monitored for nonunion.