Multiple insufficiency fractures mimicking bilateral sacroiliitis

The aim of this case report was to represent a case with multiple insufficiency fractures detected in an elderly female patient who was referred to our clinic for the differential diagnosis of bilateral sacroiliitis. A 71-year-old female patient was admitted to our outpatient clinic with the complaint of low back pain and also pain in her both hips and groin. On assessment of her musculoskeletal system, she had limited range of motion for low back and also had bilateral painful hip rotations. Bilateral Faber, Mennel and sacroiliac compression tests were positive. In her laboratory examination, 25-hydroxy-Dvit level was 3 ng/ml and parathormone level was 70 pg/ ml. In consistent with physical examination pelvic radiograph revealed bilateral subchondral sclerosis in the sacroiliac joint, narrowing in the coxafemoral joint space, irregularity in symphisis pubis. Sacroiliac magnetic resonance imaging showed diffuse hypointense signal on T1-weighted images and hyperintense signal change on STIR images in the periarticular surfaces of bilateral sacroiliac joints and also fracture lines were detected on T1-weighted images. Subsequently, multiple insufficiency fracture lines were detected on the anterior face of the sacrum, bilateral iliac bones and the pubic ramus on the sacroiliac computed tomography. The patient was diagnosed with multiple insufficiency fractures due to vitamin D deficiency. Vitamin D was replaced and conservative treatment was planned. In conclusion, insufficiency fractures should be considered in differential diagnosis in elderly patients who present with low back pain and who have joint changes that may mimic sacroiliitis in imaging.