CT-Detected Intravertebral Cleft Predicts Radiographic Collapse Progression After Body-Cast Treatment of Acute Osteoporotic Vertebral Fractures

Background: Progressive radiographic collapse after osteoporotic vertebral fractures (OVFs) may lead to kyphotic deformity. Predictors remain inconsistent, partly because prior studies used heterogeneous conservative treatment protocols that may alter collapse risk. Questions/Purposes: We asked (1) how much vertebral compression progressed after a standardized body-cast protocol, (2) which factors were associated with progression, and (3) whether computed tomography (CT)-detected intravertebral cleft (IVC) independently predicted progression. Methods: We retrospectively reviewed 162 patients with 202 acute OVFs from a single institution who were treated with early body-cast immobilization followed by rigid bracing between April 2013 and March 2016. Follow-up radiographs obtained 6 to 13 months after injury were used to assess collapse progression, defined as the change in anterior vertebral body compression percentage between baseline and follow-up. Baseline CT and magnetic resonance imaging (MRI) obtained within 2 weeks of injury were used to assess cortical wall fractures, MRI signal patterns, and IVCs. Variables with P < .10 on univariate analysis entered multivariable linear regression models. Results: Mean anterior vertebral body compression percentage increased from 22.2% to 29.0% (mean progression, 6.9%). Vertebrae with IVCs progressed more than those without IVCs (≥3 mm, 13.8%; 1-<3 mm, 14.0%; none, 4.9%). In multivariable analysis, IVC was the only independent predictor of greater radiographic collapse progression. Conclusions: This retrospective observational study found that baseline CT-detected IVC of at least 1 mm identified vertebrae at risk for radiographic collapse progression despite standardized body-cast treatment. This finding should be interpreted as a radiographic risk marker, not direct evidence of treatment failure. Level of Evidence: Level III, retrospective prognostic study.