Lumbar Discogenic Pain (internal disc disruption)

Who: Younger adults with axial low back pain. The younger the patient, the more likely the disc — increasing age carries a falling probability of internal disc disruption and a rising probability of PIV joint and SIJ pain to about 70 [1].
What: Central or bilateral low back pain, deep ache or pressure rather than sharp, ± non-dermatomal buttock or posterior thigh referral, usually not below the knee.
How it behaves: Aggs: sitting, sustained flexion, rising from sitting, driving, lifting. Eases: standing, walking, lying flat.

The illness script in one line:

A disc that has been internally disrupted but is still holding together — so the back is loading- and flexion-sensitive, the referral is vague and non-dermatomal because it is not a root, and the whole thing has a direction that makes it better.

The one thing to take from this page:

Centralisation rules the disc in. Nothing rules it out. And you find the direction first — you do not diagnose the disc and then prescribe the direction.

[2][1][3][4][5][6][7][8][9][10]

📌 READ THIS PAGE AGAINST THE CERVICAL ONE — the contrast is the teaching

The cervical discogenic page is written as a refutation. This one is not, and it is not a matter of taste. Three numbers come out the other way:

([4], which grades both regions in the same sentence [2] [1] [5] [7] [8].)

So the verdict flips. In the neck, "discogenic" is a label you can name and cannot test. In the low back it is the most common single source anyone has measured, with a blinded physical test attached. A student should be able to say why the two pages differ, in one sentence, without looking.

And here is what still does not follow. The Australian Standard manages this patient identically either way; the test rules in and never out; and the reference standard the whole thing is calibrated against damages the disc it punctures (§5). Recognise the pattern. Keep it out of the diagnosis box.

✅ Australia has a Standard, it covers this patient, and it names this pattern's imaging substrate only to tell you not to over-read it. The ACSQHC Low Back Pain Clinical Care Standard (2022) contains no discogenic subgroup anywhere. The disc appears once — Quality statement 3, where you are told to advise the patient that "disc degeneration; facet joint arthritis; and disc bulges, fissures and protrusions are very common in people without pain".

Notice the word "fissures". The annular fissure is internal disc disruption on a scan. The Australian Standard lists it among the incidental findings. That is not an oversight — it is the position. The lumbar PIV joint page records the facet half of the same sentence; this page records the disc half. Say both halves when your educator asks "says who?"

Patterns > Labels. "L5-S1 discogenic pain" names a tissue you cannot verify without an injection that harms it. A flexion- and sitting-sensitive back that centralises on repeated extension names something you can treat on Monday.

Five stages, in order. 70/30 is a working heuristic, not an established statistic — the "70%" figure traces to a single expert on a 2026 reasoning panel, not to a consensus finding. Use it as a habit, not a citation.

On this pattern the subjective gets you to a defensible hypothesis and a direction to test. It does not get you to a diagnosis, and the reason is a single sentence from the founding prevalence study: in 92 consecutive patients, "none of the clinical tests used could differentiate between those patients with internal disc disruption and other patients" [2]. The most current Australian appraisal says the same thing thirty-one years later: "no clinical features have been consistently validated as predictive" of discogenic low back pain [11].

That is better than the cervical page, where there is nothing at all. It is still not a test.

MAIN PROBLEM

"It's a deep ache right through the middle of my back. Sitting kills it, and getting out of the chair is the worst bit."

Deep, central, load-linked. Ask them what makes it worse before you ask them where it is — the behaviour carries more information than the map on this pattern.

BODY CHART

• P1: central or bilateral low lumbar. Mark P2 separately — usually buttock or posterior thigh, non-dermatomal, usually not below the knee. φp where genuinely pain-free. ✓✓ / NAD for the segments you cleared.
• 📌 FLAGGED CORRECTION. A common teaching lists "central or bilateral … non-dermatomal" as if it discriminates. It does not. No clinical test separated internal disc disruption from other conditions in 92 consecutive patients [2], and no pain-location index test was informative across 62 studies [8].
• What that means at the body chart. Location tells you where to look, not what you found. A central chart does not rule the disc in and a unilateral one does not rule it out. Keep "below the knee + dermatomal + a matching neurological deficit" as the radicular discriminator — see lumbar radicular pain.
• Mark the other side. Bilateral leg symptoms are a red flag question, not a body-chart detail.

BEHAVIOUR

• Aggs: sitting, sustained flexion, rising from sitting, driving, lifting, forward bending.
  Eases: standing, walking, lying flat, changing position.
• 24-hr pattern: sitting, sustained flexion and driving build it; standing, walking and lying flat ease it. Morning stiffness under 30 minutes = M.
• Night: lying flat is in the Eases. Unremitting night pain is in the referral table in §6.
• Severity: VAS 0–10 at best / at worst / right now.
• Coding: usually In or P — grumbling and load-linked. Morning stiffness <30 min = M, >30 min = In (and >30 min should make you re-ask the inflammatory screen).
• Irritability, all three parts, because it sets your dosage: resting symptoms present? how vigorous is the activity that provokes it? how long to settle? High irritability → repeated movements to P1 only, no overpressure, fewer reps, more sets across the day.
• 📌 The one behavioural item with a published direction: pain on rising from sitting. Present → points toward the disc. Absent → points toward the PIV joint [12]. Reported as associations — χ², phi and odds ratios — not as sensitivity and specificity. Ask it every time; quote it as a direction, never as a number.
• 📌 And keep the rest honest. Flexion-based postures, flexion movements and prolonged sitting carry modest diagnostic value; axial loading and Valsalva carry none [11]. This is the best-supported subjective block on the page and it is still only modest.
• 📌 "Delayed pain after activity or heavy load" has never been tested. Nobody has measured a next-day loading response against any lumbar reference standard. It is a heuristic — use it to recognise the pattern, not to argue for it.

HISTORY

• Insidious onset, or a clear loading exposure. Both are on-pattern.
• 📌 Ask specifically about pain BETWEEN episodes. "Persistent pain between acute episodes" is one of only three clinical variables ever shown to predict a positive discogram — specificity 83–92%, likelihood ratios 2.0–4.1, alongside a significant loss of extension and a subjective report of "vulnerability" in the neutral zone ([13], 107 unconfounded cases). A back that never fully switches off between flare-ups is a real pointer.
• Previous episodes, trajectory, previous imaging, previous injections.
• What they have been told, and what they believe. Someone holding a report that says "L5-S1 annular fissure, disc bulge" is managing a different problem in their head from the one in their back. §5 gives you the numbers to fix that.

SPECIAL / SCREENING QUESTIONS

Every patient. Every time. Out loud, before you touch them.

• Cauda equina, asked directly: bladder (retention, poor stream, reduced sensation of filling, painless leaking), bowel, saddle or perineal sensory change, sexual dysfunction, bilateral leg symptoms, progressive weakness. §4 says what those answers are worth — and it is less than you were taught.
• Fracture, malignancy, infection, inflammatory disease. Screen on combinations, not single flags (§4).
• Psychosocial screen is not optional on this pattern — ACSQHC Quality statement 2 makes it mandatory, early and repeated, and names STarT Back and the 10-item Örebro. §5 explains why it also changes what your physical test is worth.
• General health, medications, weight change, night pain that does not vary with position.

CLOSE THE SUBJECTIVE PROPERLY

Before you stand up, you should be able to say: flexion- and sitting-sensitive, worse rising from sitting, non-dermatomal referral, neurologically clear, and I am going to test for a direction. That is a hypothesis with a plan attached. It is not a diagnosis, and §5 is where it earns or loses its status.

Clear the dangerous one first. Cauda equina is not a competing hypothesis, it is an exclusion, and it lives in §4. Then rank the three that actually compete, one discriminating feature each.

And the one it actually becomes most of the time: non-specific low back pain. No discriminating feature, because that is the definition. Even in tertiary practice with a full injection work-up, discogenic pain accounted for 21.8% (95% CI 17–26%) of all low back pain seen [3]. This is the fallback whenever there is no direction — which is roughly half of true discogenic cases [5][6].

📌 CORRECTION — they rarely coexist

A common teaching says: "Facet dysfunction often coexists with discogenic pain."

The only study that ever tested both structures in the same patients points the other way. Ninety-two consecutive chronic low back pain patients had both discography and zygapophysial joint blocks: 36 (39%) had a positive discogram, 8 responded to comparative blocks, and only 3 had both. The authors' conclusion: "the combination of discogenic pain and zygapophyseal joint pain is uncommon" [10].

Small numbers, one cohort, 1994 — but it is the only direct evidence, and it kills the co-occurrence pearl in both directions. The lumbar PIV joint page carries the identical finding from the other side. The two pages agree.

The honest instruction

Screen cauda equina. Clear the neurological examination. Run repeated movements and look for centralisation or a directional preference.

• If it centralises, you have the strongest single pointer available to any lumbar structure. Record it as a hypothesis and treat the direction.
• If it does not, you have learned almost nothing, because a negative rules nothing out (−LR 0.56). You are on the non-specific page, and that is a legitimate place to be.

Record it in the Jones sense — sources of symptoms: lumbar intervertebral disc, moderate confidence, on the basis of centralisation. Never as a diagnosis, and check it with your educator before it goes in the notes.