Radiologic Changes in the Symphysis Pubis of Male Patients with Ankylosing Spondylitis.

OBJECTIVE

We aimed to evaluate the involvement of the symphysis pubis in patients with ankylosing spondylitis (AS), and to assess the correlations between symphysis pubis changes and clinical findings.

METHODS

We retrospectively evaluated a total of 222 male patients with AS who underwent pelvic and cervical/lumbar spine radiography at the Hanyang University Hospital for Rheumatic Diseases from August 2004 to February 2014. Radiographs were examined by 2 experienced radiologists, and radiographic damage was scored as follows: 0 (no damage), 1 (subtle irregularity and/or subchondral sclerosis), 2 (erosion), 3 (partial ankylosis), and 4 (total ankylosis). We evaluated the patients' clinical characteristics and analyzed their correlations with radiographic symphysis pubis changes.

RESULTS

The mean patient age was 30.5 ± 8.3 years and mean disease duration was 7.1 ± 4.6 years; 105 patients (47.3%) exhibited radiologic damage in the symphysis pubis. Moreover, 75, 28, 0, and 2 patients had scores of 1, 2, 3, and 4, respectively. When comparing the normal (score 0) and abnormal (score 1-4) symphysis pubis groups, the latter had a longer symptom duration (10.1 ± 7.0 vs 7.6 ± 5.8 yrs, p = 0.004) and higher modified Stoke Ankylosing Spondylitis Spine Score (mSASSS; 18.6 ± 17.0 vs. 14.3 ± 13.4, p = 0.038). Moreover, a significant correlation was noted between the radiographic symphysis pubis damage score and mSASSS (r(2) = 0.147, p = 0.029).

CONCLUSION

Among male patients with AS, 47.3% exhibited symphysis pubis involvement. Moreover, a correlation was observed between the radiographic symphysis pubis and spine changes.