Osteoporotic sacral insufficiency fracture

Sacral insufficiency fractures (SIFs) are easily neglected by clinical physicians. The incidence of SIFs remains unclear in patients with symptomatic osteoporotic compression fractures of the lumbar-sacral area. This retrospective study was conducted by reviewing the medical records and radiological reports and by reading magnetic resonance (MR) images from August 2013 to July 2016.We identified 1233 cases with symptomatic vertebral compression fractures for which surgical interventions were performed. A total of 1144 cases were eligible for this study. Neglected diagnoses by radiologists and clinical physicians were calculated, respectively. The MR imaging (MRI) findings of SIFs were divided into the body (S1, S2, S3, and S4 levels) and alar areas (unilateral, bilateral, transverse, and none). A total of 34 (3.00%) cases with SIFs were identified through MRI. A significant difference was observed between 19 (6.53%) patients aged>80 years and 15 (1.76%) aged<80 years (P< .0001). Eight (23.53%) and 26 (76.47%) cases of SIFs were neglected by radiologists and clinical physicians, respectively. The S2 and S3 levels were the predominantly involved area (23/34; 67.65%). Furthermore, the bilateral alar area was the most commonly involved (19/34; 55.88%), as observed in coronal views of MRI. While treating other levels of osteoporotic compression fractures, radiologists and clinical physicians should be aware of SIFs, particularly when the patients are aged >80 years. The coronal oblique MR images of the thoracolumbar region should be carefully read to avoid neglecting SIFs. Abbreviations: BMD = bone mineral density, MR = magnetic resonance, MRI = MR imaging, S = sacrum, SIFs = sacral insufficiency fractures.