MRI, MRI and MRI. It's a miracle tool, and should be used when so much is at stake.
There is a procedure of diagnostic probing and questions. It is based on a very logical sequence and has been improved over the last hundred years or more. Sorry, name eludes me for the moment, but your GP will know it. It's far more searching than you'd think possible.
Discs do not slip. They herniate, or become damaged in one way or another, but slithering out of their resting place is not what they do.
The telemetry from that mess of spasm-locked parts causes corrupt data, and the corrective signals in turn cause more supportive spasm and chaos. Did I mention the pain? The power going into the supportive signal is enough to knock the breath the strongest patient. So, the first thing they have to do is release the spasm. Things won't budge until the spine is unloaded. (that's what the knee up, on the edge of a firm bed and twisting force is all about.)
It is astonishingly easy for the facet joints to travel past a safe point and get jammed edge on, or even possibly with their own encapsulation material - so that moving back into place is not possible. This is perhaps the one that Physiotherapists like the most, cos they can make a huge improvement in five minutes of manipulation. The problem is, when to launch into that pummeling. I am very critical of the way in which some 'Doctors' in the UK. (qualified in various US 'universities' ) simply launch into procedures without ANY tests.
Proper diagnosis is vital, but the temptation to be almost perfect in a moment, after being in agony for a protracted period of time, is strong motivation to take a chance.
Edit for allude v eludes Still can't remember it though.
