|ECR 2019 / C-3035|
|Unilateral Acute Sacroiliitis - Think Infection, No Injection !|
Findings and procedure details
We present a case-series of four patients who presented to our hospitals (3 in Romford, UK and one in Abu Dhabi, UAE) as worsening lower back /RIGHT hip pain with rapid deterioration of mobility:
Case 1: A 13 year old girl presented with right sided unilteral sacroiliitis with effusion and a small anterior subiliacus collection on the MRI study with restricted diffusion. An ultrasound guided aspiration was performed yielding 10 mL of thick purulent material. The microbiology culture grew Staphylococcus aureus and patient was treated with penicillins for 3 months making an unremarkable recovery.
Case 2: A 35 year old lady presented with right sided sacroiliitis and a large subiliacus collection. CT-guided fluid aspiration was performed yielding a growth of Staph. aureus treated accordingly.
Case 3: A 30 year old man had a noncontrast CT KUB for suspected right renal colic. Osteomyelitis of the posterior ileum(with sequestrum) was demonstrated on the CT study confirmed on subsequent MRI with associated septic arthritis of the ligamentous portion of the SI joint. An image guided biopsy was advised but patient was lost to follow-up for six weeks; representing with a large gluteal intamuscular abscess. A diagnosis of tuberculous septic arthritis was made and an US guided aspiration yielded 80 mL of purulent material. Patient was started emperically on anti-tuberculous therapy with a positive growth of Mycobacterium tuberculosis confirmed at six weeks.
Case 4: An 18 year old young man presented with worsening lower back and muscle pain with raised serum creatine kinase levels and normal inflammatory markers. MR features of very mild inferior right sacroiliitis and bilateral nonspecific focal muscle oedema in the gluteus medius muscles. An initial diagnosis of myositis and inflammatory sacroiliitis was made. Open muscle biopsy was negative. IV hydration and oral steroid were started with transient symptomatic improvement. A CT-guide Intra-articular steroid injection was contemplated. The unilaterality of sacroiliitis showed some progression on the repeat MR study at two weeks; raising concern for an underlying infective aetiology.
There was a history of consumption of unpasteurised camel milk and therefore Brucella sacroiliitis was suspected. The subsequent serology was strongly positive (1:640) for both B. militensis and B. abortus. No intra-articular steroid injection was given and patient was commenced on appropriate antimcrobial therapy. Patient was completely asymptomatic on the subsequent follow-up's at 6 and 12 weeks.