Sacro-Iliac Joint
The sacro-iliac joint is very difficult to stress so that pain in the sacro-iliac joint can be differentiated from other causes of low back pain.  The clinical tests of sacro-iliac joint pain are neither sensitive nor specific.  Bone scans and computerized tomography can help to localize abnormalities to the sacro-iliac joints.  The only real way to confirm sacro-iliac joint pain is with the use of local anesthetic injections under radiographic control.  Corticosteroids can also be injected simultaneously as a therapeutic maneuver.  In any case of sacro-iliac abnormality without preceding trauma, further investigation is necessary to diagnose/exclude any spondyloarthropathies.  If sacro-iliac pain is diagnosed and does not respond to conservative measures, local fusion can be attempted.

Sacro-iliac sprain can be diagnosed using ‘Gaenslen’s test’.  The diagnosis is made by hyper-flexing the hip on the unaffected hip and therefore locking the pelvis and hyper-extending the hip on the affected side.  Pain indicates the presence of a sacro-iliac strain.  It can take up to six weeks to recover.