Background Bone and joint infections are polymorphic and can take various forms. Infectious sacroiliitis are a special rare form and a misleading diagnosis.
Methods This is a retrospective study of 17 cases of infectious sacroiliitis collected in department of Rheumatology and Infectious Diseases in Hospital Farhat Hached in Tunisia over a period of 21 years [1993-2013].
Results Our population consists of 10 women and 7 men with a mean age of 42.7 years [21-78 years]. Clinical signs of appeal were inflammatory buttock pain (n=17), low back pain (n=1), pseudo- radicular pain (n=2) and a major functional impairment (n=4). General symptoms observed were fever (n=15), night sweats (n=7) and deterioration of the general status (n=12). These symptoms were acute in 7 cases, subacute and chronic in 5 cases each. Comorbidities were diabetes (n=1) and hemodialysis (n=1). The inflammatory syndrome was missing in one case, and leukopenia was noted in 3 cases. Standard radiographs were normal in 6 cases. Soft tissue abscess were objectified by CT (n=5) and MRI (n=1). Contributing factors of sacroiliitis were urinary tract infection (n=7), genital infection (n=1), recent blood transfusion (n=1), intramuscular injection (n=1), skin infection (n=3) and pregnancy (n=4) (1 case of ongoing pregnancy, 1 case of peri -abortion and 2 cases of post- partum). In 6 cases, sacroiliitis was secondary to sepsis. The causative organisms were isolated in 13 cases by blood cultures (n=4), urinalysis (n=4), biopsy of the sacroiliac joint (n=1), biopsy of soft tissue abscess (n=3) and Wright serology (n=5). Identified germs were brucellosis (n=5), Staphylococcus aureus (n=4), Escherichia coli (n=4), Mycobacterium tuberculosis (n=2), Klebsiella pneumonia (n=1), Klebsiella oxytoca (n=1) and Pseudomonas aeruginosa (n=1). Associated osteoarticular infectious locations occurred in 5 cases. These were an infectious spondylitis (n=2), a symphysis pubis arthritis (n=2), a shoulder arthritis (n=1) and a hip bilateral arthritis (n=1). The treatment consisted of appropriate antibiotics in all cases and surgical drainage of soft tissue abscess resistant to medical treatment in one case. The outcome was unfavorable in 2 patients who presented with septic shock.
Conclusions The diagnosis of infectious sacroiliitis should be considered in any febrile buttock pain, especially in case of some contexts (septicemia, urogenital infections, peri-partum ...).
Disclosure of Interest None declared