The prevalence of vertebral fractures in spondyloarthritis: relation to disease characteristics, bone mineral density, syndesmophytes and history of back pain and trauma

Abstract

IntroductionAn increased risk of vertebral fracture (VF) is one of the extra-articular manifestations of spondyloarthropathy (SpA). The prevalence of moderate to severe VFs visualized by radiography (Rx) in patients with SpA in daily practice is unknown until imaging of the full spine is available, as most VFs do not present with clinical signs and symptoms of an acute fracture.MethodsWe evaluated the prevalence of VFs (>25 % loss in height) on available Rx and dual-energy X-ray absorptiometry (DXA) images in 390 consecutive patients with SpA in daily practice. We assessed their association with disease characteristics, bone mineral density, the modified Stoke Ankylosing Spondylitis Spinal Score, and history of trauma.ResultsForty-six patients (11.8 %) had Rx VF (56.4 % men, 93.5 % in the thoracic spine), and 44.5 % had multiple VFs. Compared with patients without VF, patients with VF were older (52.2 vs. 47.3 years, p < 0.01; range 25–84 years), had lower femoral neck T-scores (−1.1 vs. −0.7; p < 0.05), and had a marginally higher modified Stoke Ankylosing Spondylitis Spinal Score (11.7 vs. 7.0; p = 0.06). Among patients with VFs, 15.2 % had a history of trauma with acute back pain (p < 0.001 vs. no VF). The reliability of DXA for diagnosing radiographic VFs was high (κ 0.90).ConclusionsModerate to severe VFs are found in more than 10 % of patients with SpA before the age of 40 years in 5 % of women and 9 % in men. Most VFs are located in the thoracic region, are related to low femoral neck bone mineral density and to stiffening of the spine, and are only rarely related to trauma history. DXA is a useful alternative for diagnosing VFs.

Spinal fractures in patients with ankylosing spondylitis

“…Several surveys have reported the prevalence of clinical and morphometric vertebral fractures in AS (Table 1). These studies [8,10,24,25,28,29,31,[57][58][59][60][61][62][63][64] indicate that vertebral fractures represent a regular finding in patients with AS, but their prevalence is highly variable ranging from 0.4 [8] to 40.9 % [64]. Such discrepancies in prevalence rates reflect differences in recruitment and vertebral fracture assessment methods, sex distribution, age, study design, and inconsistency in the definition of vertebral fractures (Table 1).…”

“…The reported prevalence rates of osteoporosis in patients with AS range between 19 and 62 %, with this high variability mainly attributed to technical difficulties in assessing spinal bone mineral density, that can result falsely elevated in AS due to ligament ossification, sclerosis of the vertebral margins, and syndesmophytes formation [8,18,[23][24][25][26][27]. More recent prospective data on osteoporosis have shown prevalence rates between 21 and 25 % [10,18,28,29]. Loss of bone mineral density may occur even in early stages of the disease in connection with the inflammation process, independent of spine mobility and exercise [4,7,30].…”

“…However, this study involved clinical vertebral fractures; thus, it still remained unclear what is the exact prevalence and incidence of morphometric vertebral fractures in AS. Prevalence of morphometric vertebral fractures ranged from 11.8 to 32.4 % in more recent studies [10,24,28,29,60] using systematic imaging methods of the spine (either radiographic, or the vertebral fracture assessment method by dual-energy X-ray absorptiometry). It should be kept in mind, however, that all the vertebral fractures are those which come to clinical attention, which may represent a minority of them.…”

“…Increasing interest in VFA-DXA is due to its high negative predictive value compared with radiography, with possible clinical consequence for screening. Geusens et al [29] have suggested that VFA could be used as a prescreening tool for the presence of subclinical vertebral fractures in spondyloarthritis, limiting the use of radiographs to patients with a vertebral fracture on VFA or when VFA is not of adequate quality.…”

“…Vertebral fracture assessment (VFA) using dual-energy X-ray absorptiometry (DXA) technology represents a practical, fast, and low-radiation technique able to produce images of sufficient quality to diagnose the presence of vertebral deformity consistent with fracture [10,29]. Increasing interest in VFA-DXA is due to its high negative predictive value compared with radiography, with possible clinical consequence for screening.…”