COPD and osteoporosis: detection and grading of vertebral fractures on lateral chest radiography

Chronic obstructive pulmonary disease (COPD) is a complex disease that is highly associated with osteoporosis, which tends to be underdiagnosed and therefore, undertreated. Our purpose was to examine the interobserver variability of the detection and grading of vertebral fractures on routine chest radiographs in patients presenting with severe COPD.

Routine lateral chest x-rays from 43 patients (male=25) suffering from severe COPD (Global Initiative on Obstructive Lung Diseases III/IV) were evaluated retrospectively by 2 board certified radiologists and 1 radiology resident for signs of osteoporosis and vertebral fractures by using a validated semiquantitative method according to H. Genant et al. No patient suffered from significant back pain or radicular symptoms. The presence or absence of signs of osteoporosis and/or vertebral fractures were analysed in the official radiologic report.

The mean age of the population was 61 years, and the median body mass index was 23. All patients had a history of severe smoking (median 51 pack/y). Seventy-two chest radiographs, including follow-up examinations, were evaluated independently. Overall interobserver variability was moderate (kappa 0.42 to 0.50). However, regarding the detection of moderate and severe or severe fractures alone, interobserver variability was 0.76, respectively. Vertebral fractures were mentioned in only 4 of 72 (9%) official radiology reports.

Osteoporotic vertebral fractures are frequently underdiagnosed in patients with COPD. There is an overall moderate interobserver variability for the detection and scoring of vertebral fractures even in a study setting, but variability regarding diagnosis of moderate and/or severe fractures is substantial.