Osteoporotic vertebral fractures without compression: key factors of diagnosis and initial outcome of treatment with cement augmentation

Abstract

Because of the nonspecific symptoms and unapparent radiographic findings, occult osteoporotic vertebral fractures (VFs) have a high rate of missed diagnosis, and the treatment of these fractures has rarely been discussed in the literature. We investigated diagnostic key factors of such occult VFs and evaluated the effects of cement augmentation in these patients. A total of 225 patients with VFs treated with vertebroplasty (VP) or kyphoplasty (KP) were retrospectively analyzed. All patients have taken preoperatively magnetic resonance imaging (MRI) including T1/T2-weighted images and short tau inversion recovery (STIR) sequences, and 45 patients met the inclusion criteria. Clinical outcomes were evaluated by comparing visual analog scale (VAS) and Oswestry disability index (ODI) values preoperatively, postoperatively, and at the final follow-up. MRI (T1 and STIR sequences) showed bone marrow edema in all fresh fractures including occult VFs and concomitant VFs; five patients showed no abnormality signal in their T2-weighted sequences of occult VFs. While 40 patients underwent KP, and five patients underwent VP. We did not find delayed collapsed fractures in the augmented occult VFs in both groups after operation. Both groups had significant improvement in pain and functional activity after the intervention (p<0.01). The presence of previous or concomitant VFs leads to further imaging examination, which helps identify the occult VFs. Preoperative MRI examination especially T1 and STIR sequences plays a vital role in the early diagnosis of occult VFs. Except for significant pain relief and functional improvement, VP and KP can effectively prevent delayed vertebral collapse of occult VFs comparing to previous reported data.