- Incidence: 0.40 cases per 100,000 person-years
- Peak incidence: 40-50 years
- Sex ratio: 1:1
- Haematogenous spread of bacteria
- Staphylococcus aureus: most common
- Crohn's (commonest cause in this category)
- Diverticulitis, colorectal cancer
- UTI, GU cancers
- Vertebral osteomyelitis
- Femoral catheter, lithotripsy
- Patient in the supine position with the knee flexed and the hip mildly externally rotated
- Specific tests to diagnose iliopsoas inflammation:
- Place hand proximal to the patient's ipsilateral knee and ask patient to lift thigh against your hand. This will cause pain due to contraction of the psoas muscle.
- Lie the patient on the normal side and hyperextend the affected hip. In inflammation this should elicit pain as the psoas muscle is stretched.