Background: Most osteoporotic vertebral fractures (OVFs) occur in the thoracolumbar area without neurological symptoms. The pathogenesis and clinical results of symptomatic lower lumbar OVFs have not been analysed. We aimed to retrospectively investigate the risk factors for the occurrence of neurological symptoms in patients with lower lumbar OVFs and to assess the clinical results of these symptoms using magnetic resonance (MR) images.
Methods: Of the 104 patients enrolled, 21% reported neurological symptoms. We divided OVFs with neurological symptoms into various types using early MR images and investigated the risk factors for each type. Clinical results of symptomatic patients were also evaluated.
Results: Symptomatic patients with lower lumbar OVFs mainly had one of two fracture types, indicated by total low and superior/inferior low-intensity signals on T1-weighted images. A multivariate logistic regression analysis showed that a smaller canal area and longer disease duration were risk factors for all patients. For patients with OVFs indicated by total low intensity, symptomatic patients had a significantly smaller canal area than non-symptomatic patients. For patients with OVFs indicated by superior/inferior low intensity, symptomatic patients had a significantly higher frequency of L4 and L5 vertebral fractures, longer disease duration, smaller canal area, smaller angle between the facets, and higher frequency of coexisting degenerative spondylolisthesis than non-symptomatic patients. Symptomatic patients with OVFs indicated by total low intensity had poorer clinical results regarding walking ability than symptomatic patients with OVFs indicated by superior/inferior low intensity.
Conclusions: Lower lumbar OVFs with neurological symptoms might have two different pathogeneses according to early MR images. Compared with symptomatic patients with OVFs indicated by superior/inferior low intensity, symptomatic patients with OVFs indicated by total low intensity may require different treatment strategies to avoid symptoms.
Keywords: Intervertebral instability; Lower lumbar spine; Lumbar canal stenosis; Magnetic resonance imaging; Neurological symptoms; Osteoporotic vertebral fracture.