Fig. 3
a Case 12: MRI performed 1 week after onset of the patient’s symptoms showed high signal intensity in the left SIJ and iliacus muscle with abscess formation. The patient was operated by combined anterior and posterior debridement. Full mobilisation was allowed after 2 weeks. The patient was satisfied. b FU MRI after 2 months revealed no more abnormal inflammatory signals. At the last FU visit after 80 months, the patient had excellent functional outcome