Objective: Males with chronic obstructive pulmonary disease (COPD) are at increased risk for developing osteoporosis (OP) with subsequent vertebral compression fractures. Such fractures with resultant increased thoracic kyphotic angle (TKA) may interfere with these patients' already compromised pulmonary function. A retrospective cross-sectional study was performed to evaluate the recognition and treatment of vertebral fractures in male patients with COPD.
Methods: The study population included male patients with COPD aged 55 years and older who had a lateral chest X-ray (index film) performed between January 1, 2001 and July 5, 2005. Vertebral fractures and the TKA were determined independently by two different radiologists. One radiologist (reviewer #1) used direct measurement including quantitative morphometric analysis to determine fractures and the TKA, whereas the second radiologist (reviewer #2) used visual inspection only. Inter-reader agreement for vertebral fractures and TKA was assessed. The computerized charts were reviewed to determine the initial recognition of vertebral fractures and the subsequent therapy. Logistic regression was employed to determine significant risk factors for vertebral fractures in this male population.
Results: Three hundred and fifty male study subjects and their index lateral chest X-rays were reviewed. Ages ranged from 52 to 90 and 9/350 (2.6%) of the study subjects had vertebral fractures identified on the initial radiology report. None of these nine patients were subsequently treated with anti-osteoporotic agents other than calcium and vitamin D, and two of them had a follow-up central bone density. Reviewer #1 measured 361 fractures in 181 subjects and determined the mean TKA to be 31.43 (+/-8.62) degrees. Reviewer #2 identified 27 fractures in 19 subjects and with an estimated mean TKA of 24.84 (+/-8.53) degrees. There was little inter-observer agreement with vertebral fractures (kappa=0.07), but there was a strong positive correlation with the TKA (r=0.79). There was a weak to moderate correlation with the TKA and the presence of vertebral fractures (r=0.26). Significant risk factors for vertebral fractures included smoking status (odds ratio 1.84 [1.08-3.15]) and age (odds ratio 1.06 [1.03-1.09] for each year increase in age).
Conclusion: A large number of vertebral fractures in males with COPD goes undiagnosed. In those patients with diagnosed vertebral fractures, follow-up therapy is under-utilized. When analyzing lateral chest X-rays for vertebral fractures, visual inspection alone without direct measurement may not be an adequate technique for identifying fractures.