The base-rate problem

Brinjikji and colleagues pooled 33 studies of people without back pain: 37% of asymptomatic 20-year-olds show disc degeneration, rising to 96% by age 80; disc bulges rise from 30% to 84% across the same span. Boden reported the same phenomenon in 1990.

A finding that common cannot, by itself, distinguish a painful spine from a painless one. It is context, not conclusion.

What correlation actually means

• Does the level of the finding match the distribution of the symptoms?
• Does the side match?
• Do the examination findings — reflex, strength, sensation — map to the root the imaging implicates?
• If they do not, which is more likely wrong: the picture, or the person?

A reviewing report that recites findings without performing this correlation has skipped the step that converts an image into evidence, and that omission is visible on the face of the report.

Dating, honestly

Certain features suggest acuity, and a comparison with any prior study is worth more than all of them. A confident date derived from a single post-injury scan usually overstates what imaging supports, and we will not provide one.

Where no prior imaging exists, the honest statement is that the structural change is chronic and what changed is the symptom — which is the eggshell position, and a stronger one than a date nobody can defend.

This practice is not aligned to a side. Its obligation runs to the patient’s health and safety, which is the same reason it is not beholden to any position that would keep it from seeing what is actually there. We do not offer opinions on liability, we do not accept a referral or a review conditioned on reaching a particular conclusion, and we will say plainly when the evidence does not support the claim — whichever party was hoping otherwise.

Common questions

Related reading

• “Pre-existing degeneration”
• Objective corroboration
• Diagnostic nerve blocks
• Lumbar disc injury
• Causation and apportionment