Introduction:

Osteoporotic vertebral fractures (OVFs) are becoming a significant socio-economic problem as the percentage of older people in the population increases. Although there have been some studies which have focused on the fractured vertebral body, there have been few reports of spinous process fractures (SPFs) in the osteoporotic spine. The purpose of this study was to assess the radiological and clinical outcomes of OVF accompanied by SPF.

Methods:

A cross-sectional observational study was performed at our hospital. We evaluated patients who were suffering pain due to single-level OVF and an intravertebral cleft. For inclusion in the study, the requisite duration was at least 12 weeks and the severity of low back pain (LBP) was greater than 40/100 mm on the visual analogue scale (VAS).  Refractory to standard medical treatment was administered. SPF was detected using magnetic resonance imaging (MRI) and computed tomography (CT). The outcomes of the plain radiograms of the vertebral fractures were evaluated from the wedging angle of the fractured vertebrae, intravertebral instability and the presence of ankylosing spinal hyperostosis. As clinical parameters, we investigated age, gender, VAS score for LBP, Oswestry Disability Index (ODI), and the period from the onset of acute fracture. To analyze the clinical and radiological data, we used the Mann-Whitney U test and statistical significance was defined as P < 0.05.

Results:

Our study included 195 patients with chronic pain (50 men, 145 women) due to single-level OVF with an intravertebral cleft. The mean age and the mean time-period from the onset of acute LBP were 77 years (range, 57-93 years) and 38 weeks (range, 12-144 weeks), respectively. In 195 OVF patients with LBP, 41 patients (20.5%) showed SPFs on MRI and CT. SPFs were observed just 1 level above the fractured vertebral body in 35 patients (85.4%), with the  same results as the fractured vertebral body in 6 patients (14.6%). The rate of incidence of SPF in the thoracic spine was higher in the SPF(+) group than that in the SPF(-) group. Regarding the presence or absence of APFs, there were no significant differences in age, gender, VAS, ODI, the time-period from the onset of acute LBP, wedging angle, intravertebral instability, or in the presence of ankylosing spinal hyperostosis.

Discussion:

SPFs occurred in 20.5% of elderly OVF patients with long-lasting LBP. In addition, SPFs often occurred just one level above the fractured vertebra, and SPFs with OVF tended to be located in the thoracic spine.