Calcaneal quantitative ultrasound has a role in out ruling low bone mineral density in axial spondyloarthropathy.

OBJECTIVE: The aim of this study was to investigate the role of quantitative ultrasound (QUS) of the calcaneus in screening for osteoporosis in adults with axial spondyloarthropathy (axSpA). METHOD: Postmenopausal women and men over 50 years with axSpA were recruited for this observational cross-sectional study. Dual-energy x-ray absorptiometry (DXA) assessed bone mineral density (BMD) of the spine and hip. QUS of the calcaneus produced broadband ultrasound attenuation (BUA), speed of sound (SOS), stiffness index (SI), and T-scores. Receiver-operating characteristics (ROC) curve analysis determined the ability of QUS to discriminate between low and normal BMD. Thresholds were identified to (1) out rule low BMD, (2) identify osteoporosis, and (3) identify low BMD. The number of DXAs which could be avoided using this approach was calculated. RESULTS: 56 participants were analyzed. BUA, SI, and T-score QUS parameters correlated with BMD by DXA; SOS did not. All QUS parameters had the ability to discriminate between low and normal BMD (area under the curve varied from 0.695 to 0.779). QUS identified individuals without low BMD with 90% confidence, with BUA performing best (sensitivity 93%, negative predictive value 86%). Using QUS as a triage tool, up to 27% of DXA assessments could have been avoided. QUS could not confidently identify individuals with osteoporosis. CONCLUSIONS: QUS of the calcaneus confidently out ruled low BMD in individuals with axSpA, reducing the need for onward DXA referral by up to 27%. QUS is promising as a non-invasive triage tool in the assessment of osteoporosis in adults with axSpA.Key Points• Osteoporosis is common in axial spondyloarthropathy (SpA), but evaluation of bone health is suboptimal in this population.• Quantitative ultrasound (QUS) of the calcaneus can out rule low bone mineral density in individuals with axial SpA, reducing the need for DXA assessment.• QUS is a promising non-invasive triage tool in the assessment of bone health in axial SpA.

Measuring bone density in axial spondyloarthropathy: Time to turn things on their side?

AIM: Osteoporosis in axial spondyloarthropathy (axSpA) is difficult to accurately diagnose due to osteoproliferation of the spine interfering with conventional (anteroposterior, AP) dual-energy X-ray absorptiometry (DXA). This study compares AP and lateral projections of DXA when assessing bone mineral density (BMD) of the spine and investigates the impact of osteoproliferation on AP DXA. METHOD: In this cross-sectional study, structured standardized assessments collected demographic, clinical, laboratory and radiographic data. DXA assessed BMD of the spine using PA and lateral projections. Hip BMD was assessed in the usual manner. World Health Organization (WHO) criteria assessed prevalence of low BMD. Incorporating lateral DXA in the bone health assessment of axSpA was investigated. SPSS was used for statistical analysis. RESULTS: A total of 100 patients had paired AP and lateral DXA studies: 78% were male, mean (SD) age 52 (12) years. BMD of the spine measured by AP projection was significantly higher than BMD measured by lateral projection (mean difference 0.34 g/cm2 , 95% CI 0.30-0.37). More patients had low BMD with lateral compared to AP projection (47% vs 16%, P = .01). At the hip, 34% of patients had low BMD. Disease duration, body mass index and radiographic severity independently predicted a difference between AP and lateral measurements of the spine. CONCLUSION: Lateral DXA of the spine is unaffected by osteoproliferation of the spine in axSpA and detects significantly more cases of low BMD than conventional AP DXA. Lateral DXA should be included in BMD assessment of patients with axSpA.

Hereditary angio-oedema as a rare cause of small-bowel obstruction.

A 52-year-old man with known hereditary angio-oedema (HAE) presented with a 2-day history of progressive severe abdominal pain, distension, nausea, vomiting and constipation. CT of his abdomen and pelvis showed small-bowel obstruction and ascites. HAE is a rare autosomal dominant disorder caused by a C1 esterase deficiency and involves episodic oedema of subcutaneous and mucosal tissues. It commonly affects the face and limbs, causing deformity; the respiratory tract, causing life-threatening laryngeal swelling; and the gastrointestinal tract, causing small-bowel obstruction. An infusion of a C1 esterase inhibitor was given to the patient. His symptoms resolved within 6 hours, and a repeat CT showed complete resolution 24 hours later. Small-bowel obstruction in HAE is often misdiagnosed, leading to ineffective treatment and unnecessary surgery. Therefore, this should be suspected in patients with HAE presenting with an acute abdomen, and clinicians should understand the unique treatment required.