A major, common and potentially dangerous observation in management pathways is the unsophisticated manner in which injection responses are considered from a diagnostic perspective.

A concordant response is negation of nociceptive input to pain in the local anaesthetic phase resulting in negation of a pain response for a time consistent with the agent used.

Anything else is DISCORDANT or of NO diagnostic value.

Anything else does NOT form a sophisticated justification for more aggressive treatment directed to that structural target.

The cortisone phase response is non-specific and can be consistent with regional or systemic uptake of corticosteroid, or just our good old (and very common) placebo construct response.

An inaccurate judgement of a diagnostic pathway to push whatever intervention is ‘believed in’ by the interpreter is simply like hammering a square peg into a round hole!

All too often it is the end point intervention that is influencing the diagnostic process and not the other way around. The requirement to apply rigorous processesis just good clinical medicine based on a logical and scientific method. Please don’t quote the ‘art of medicine’ to me again unless much improved pain outcomes are well and truly verified.

If the diagnostic responses to accurately placed (? repeated) local anaesthetic containing injections are discordant, rather than persisting in targeting structural diagnoses for increasingly harmful interventions, it is much better to consider that the discordant pain response may be due to over-protective pain ie: a pain response that is being generated by the brain due to an excessive perception of  “danger’.

Please consider also the fragility of our prevailing model in the sense that even if pathways to interventions and surgeries are PERFECTLY CONCORDANT with our current model, persistent and treatment resistant pain outcomes are STILL OBSERVED quite commonly and are still highly contextually sensitive.


Another common observation is that on the relatively rare occasions that pain charts are actually obtained they are poorly structured. Some have no pre-injection score or only one column; others have a post injection score at only 1 or 2 hours after the injection. I hope I don’t have to elaborate on how this only provides a further …

MUDDY …   

view of the result, leading to potential for inappropriate and harmful interventions including surgery, and often even repeated surgery due to pain persistence, and persisting with a mud-filled model with which to deal with it.

An excellent reference for consideration:

  • A Philosophical Foundation for Diagnostic Blocks, with Criteria for Their Validation. Engel, MacVicar, Bogduk. Pain Medicine 2014; 15: 998–1006:

“… The eight criteria for diagnostic blocks can be assembled into a metric that can be applied to assess the validity of a given block, either in general or in a particular case. The metric is hierarchical in that certain criteria are essential, others are critical, and others less critical … duration is an essential criterion. Because local anesthetic agents have a temporary effect, pain should return when that effect wears off, which should be in a matter of hours. If prolonged relief occurs after a block, the block converts into a therapeutic event, and is disqualified as a diagnostic procedure …”


I am therefore offering my version of a well constructed pain chart for use with such injections.

Once again it is open to constructive advice and criticism.

It can be seen below and downloaded via the file here on the right —>

Pain chart.pdf
Size : 19.552 Kb
Type : pdf