Extensive areas of juxta articular sclerosis of predominantly iliac margin of both sacroiliac joints, more so on the left side. To a lesser extent, similar sclerosis seen in the sacral margins of bilateral joints with partial ankylosis. There is a 9 mm pubic separation. Rest of the pelvic radiograph is normal.
Interpretation and Discussion
It could take as long as 9 years for findings to manifest in a radiograph in a clinical case of sacroiliitis.
The criteria of radiographical grading of sacroiliitis was first created in 1966, called the New York criteria and lateral modified for ankylosing spondylitis in 1984. With the advent of MRI, and its ability to detect inflammatory joint changes well ahead of a radiograph, in clinically suspected cases MRI is often done. Preliminary imaging nevertheless continues to be a first line anteroposterior pelvic radiograph and a pelvic ultrasound to rule out other obvious causes of pelvic pain.
Another finding observed in this case is of pubic separation without an accompanying fracture, which is also a cause of pelvic pain. In a non traumatic setting, the most common cause of pubic separation in women is partum. Any separation more than 10 mm is called diastasis. In this case the distance is 9 mm.
- Sudoł-Szopińska I, Kwiatkowska B, Włodkowska-Korytkowska M, Matuszewska G, Grochowska E. Diagnostics of Sacroiliitis According to ASAS Criteria: A Comparative Evaluation of Conventional Radiographs and MRI in Patients with a Clinical Suspicion of Spondyloarthropathy. Preliminary Results. (2015) Polish journal of radiology.
- Pubic diastasis on Radiopaedia.