Underdiagnosis and underreporting of vertebral fractures on chest radiographs in men aged over 50 years or postmenopausal women with and without type 2 diabetes mellitus: a retrospective cohort study

Opportunistic Computed Tomography: A Novel Opportunity for Osteoporosis Screening

STUDY DESIGN

Retrospective review.

OBJECTIVE

To use opportunistic computed tomography (CT) screening to determine the prevalence of osteoporosis (OP) in patients presenting with spinal fractures and the rate of identification and treatment at our institution.

BACKGROUND

OP remains a highly underdiagnosed and undertreated disease. Opportunistic abdominopelvic CT scans offer a feasible, accessible, and cost-effective screening tool for OP.

METHODS

Retrospective review of 519 patients presenting as trauma activation to the emergency department of a Level 1 Trauma Center after a spinal fracture. Patients were excluded if under the age of 18 or lacking a CT scan upon arrival in the emergency department. Hounsfield Units (HU) were measured at the L1 vertebral level on CT scans to determine bone density levels. Values of ≤100 HU were considered osteoporotic, whereas 101-150 HU were osteopenic.

RESULTS

A total of 424 patients were included. The average HU was 204.8 ± 74.3 HU. Of the patients, 16.7% were diagnosed as osteopenic and 9.9% as osteoporotic. The mean age was 65 ± 14 years for osteopenic patients and 77 ± 11 years for osteoporotic. A statistically significant inverse relationship was found between age and bone density. Of the patients, 42.5% with low bone density HU measurements had a previously documented history of OP/osteopenia. There was a statistically significant association between females and low bone density. Patients injured in a fall were statistically significantly more likely to have lower bone densities than those in motor vehicle accidents. Of the osteoporotic patients, 9.5% were treated by our institution's fragility fracture team.

CONCLUSIONS

Our study shows that among a cohort of patients with spinal fractures, 58% of patients with radiographic signs of OP are currently undiagnosed, resulting in a low treatment rate of OP. Increasing and standardizing the use of opportunistic CT scans would allow an increase in the diagnosis and treatment of OP in patients with spinal fractures. Further, opportunistic CT scans could also be useful for a broader orthopedic population at high risk of fragility fractures.

LEVEL OF EVIDENCE

Level II-therapeutic.

Opportunistic Identification of Vertebral Compression Fractures on CT Scans of the Chest and Abdomen, Using an AI Algorithm, in a Real-Life Setting

This study evaluated the performance of a vertebral fracture detection algorithm (HealthVCF) in a real-life setting and assessed the impact on treatment and diagnostic workflow. HealthVCF was used to identify moderate and severe vertebral compression fractures (VCF) at a Danish hospital. Around 10,000 CT scans were processed by the HealthVCF and CT scans positive for VCF formed both the baseline and 6-months follow-up cohort. To determine performance of the algorithm 1000 CT scans were evaluated by specialized radiographers to determine performance of the algorithm. Sensitivity was 0.68 (CI 0.581-0.776) and specificity 0.91 (CI 0.89-0.928). At 6-months follow-up, 18% of the 538 patients in the retrospective cohort were dead, 78 patients had been referred for a DXA scan, while 25 patients had been diagnosed with osteoporosis. A higher mortality rate was seen in patients not known with osteoporosis at baseline compared to patients known with osteoporosis at baseline, 12.8% versus 22.6% (p = 0.003). Patients receiving bisphosphonates had a lower mortality rate (9.6%) compared to the rest of the population (20.9%) (p = 0.003). HealthVCF demonstrated a poorer performance than expected, and the tested version is not generalizable to the Danish population. Based on its specificity, the HealthVCF can be used as a tool to prioritize resources in opportunistic identification of VCF's. Implementing such a tool on its own only resulted in a small number of new diagnoses of osteoporosis and referrals to DXA scans during a 6-month follow-up period. To increase efficiency, the HealthVCF should be integrated with Fracture Liaison Services (FLS).