You don't find anything unless you look for it. We treat patients, not the scan

Furthermore, you never look for it unless you know about it.
Today my considerate friend Dr Keith Goh, knowing my interest in backpain asked me to see a patient in Mt Elizabeth Medical Centre.  The overweight, 53 year old wife of the former Transport Minister of an Island in the Indian Ocean came in a wheelchair.  She used to be an active businesswoman until a year ago.  She has hypertension and diabetes and is on insulin injections.  She had a 3 month history of severe left sided low back pain with numbness in the foot, although everything started 9 months ago.  She can barely do housework or climb one flight of stairs now, and has been in and out of hospitals since January this year.  Recently she has started to have pain in the upper back and neck stiffness. In my clinic she laid on the couch as sitting aggravated the pain.  Her MRI scans suggested a neck problem.  But with careful problem oriented probing, it turned out that her problems are related to something else.

She had exquisite tenderness of the left S-I joint (sacro-iliac joint)   The Faber test was positive on the left side.  The rest of the examination did not show any signs which could be attributed to spinal cord or nerve root compression.  The straight leg raising on either side was painless up to 70 degrees.  The left foot numbness was subjective and felt over all 5 toes and non dermatomal in distribution.  She had no limb length discrepancy.

The differential diagnosis of S-I joint dysfunction include the following
a. trochanteric bursitis
b. piriformis syndrome
c. myofascial syndrome
d. lumbo-sacral disc bulge or herniation
e. limbo-sacral facet joint syndrome
f. lumbar radiculopathy
g. cluneal nerve entrapment
f. stress fracture of the sacrum

The cervical spine MRI showed fairly severe OPLL(ossified posterior longitudinal ligament) and buckling of the ligamentum flavum of C67. The lumbo-sacral MRI showed facet joint arthropathy with narrowed neuroforamina at L5-S1. 

This lady has left sacro-iliac joint dysfunction.  The left foot numbness can be attributed either to diabetic peripheral neuropathy or even referred pain from the S-I joint problem.   The left foot numbness and the interscapular pain is likely to be myofascial pain.  An altered musculoskeletal dynamics in response to S-I joint instability can certainly result in myofascial pain.

The diagnosis is clinched by injection of the S-I joint.  If any joint fluid is obtained it will need to be sent to the lab for cultures.  If pain is indeed relieved by an injection of anesthetic and steroid, other pain generators can be excluded.  Such injections are not to be belittled as I have cases who derive relief from pain for up to half a year from one such injection, long after the anesthetic had worn off.    Surgery to fuse the joint should be reserved for intractable cases. 

I will only treat the cervical problem if she develops signs of cervical cord compression. 

The diagnosis of S-I joint dysfunction does not end here.  We will have to check for ankylosing spondylitis, crystal arthropathy and S-I joint infection.  

The moral here is - assess the patient before looking at the scan images.  If we treat only pictures, our patients will be disappointed - in us.