Decoding Back Pain: Diagnostic Reasoning to Precision Interventions – Invited Lecture at 2nd Delhi Pain Summit
Introduction
Low back pain is often labelled as “nonspecific,” but in modern pain medicine we now have the tools to move from vague labels to precise diagnoses and targeted interventions.
On 9 November 2025, Dr. Gautam Das, Founder–Director of Daradia: The Pain Clinic, Kolkata, delivered this invited lecture – “Decoding Back Pain: Diagnostic Reasoning to Precision Interventions” – at the 2nd Delhi Pain Summit (Global Pain School Annual Conference), New Delhi, India.
This page hosts the lecture abstract, key learning points, detailed discussion, and links to the slides and supporting resources for pain physicians, orthopaedic surgeons, anaesthesiologists and rehabilitation professionals who wish to refine their diagnostic reasoning in back pain.
Abstract
Low back pain (LBP) remains one of the most common and disabling conditions globally, yet for decades 80–90% of cases were labelled “nonspecific” or “mechanical,” implying no clear tissue diagnosis despite significant suffering. Classic guidelines from the 1990s highlighted our inability to assign a precise pathoanatomical source in most patients, while routine imaging showed degenerative abnormalities even in asymptomatic individuals. Against this backdrop, a series of interventional studies in the 2000s demonstrated that, with structured diagnostic pathways using controlled blocks and discography, a definite pain generator could be identified in the majority of patients previously considered nonspecific. More recently, the concept of nociplastic pain and central sensitisation has further complicated, but also enriched, our understanding of chronic low back pain phenotypes.Decoding back pain
This article elaborates on the invited lecture “Decoding Back Pain: Diagnostic Reasoning to Precision Interventions” and proposes a practical, clinically grounded framework built on two essential questions: WHERE is the pain coming from? and WHY is that structure painful now? Using this dual lens, we review common nociceptive pain generators (disc, facet joints, sacroiliac joint, muscles, ligaments, vertebral body, bursae, hip joint, and deep gluteal structures), the role of careful history and targeted physical examination, and the judicious use of imaging and diagnostic blocks. We then discuss nociplastic and centrally sensitised presentations, reasons for interventional failures, and clear indications for non-intervention. The goal is not to promise perfect certainty in every case, but to replace reflex “nonspecific LBP” labels with mechanistic thinking and more precise, evidence-informed decisions about when and how to intervene.
Key Learning Points
By engaging with this lecture and slide deck, you will be able to:
- Understand why most low back pain was historically labelled “nonspecific” and what has changed in modern pain medicine.
- Apply the WHERE–WHY diagnostic framework to systematically approach back pain in daily practice.
- Differentiate between major pain generators: disc, facet joint, sacroiliac joint, myofascial structures, hip, nerve root and spinal canal pathologies.
- Recognise the role and limitations of imaging in diagnosing back pain.
- Use diagnostic blocks judiciously to confirm or refute suspected pain generators.
- Identify features of neuropathic and nociplastic low back pain and understand when interventional procedures are unlikely to help.
- Avoid common pitfalls that lead to failed back surgery or ineffective interventions.
- Integrate precision diagnosis with tailored treatment – ranging from rehabilitation and pharmacotherapy to image-guided interventions and regenerative strategies.
Slides & Resources
Slides: Decoding Back Pain: Diagnostic Reasoning to Precision Interventions
Introduction – From “Nonspecific” to Mechanism-Based Thinking
Low back pain affects up to 80% of adults at some point in their lives and is a leading cause of disability worldwide. Yet historically, our diagnostic vocabulary has been surprisingly vague. In the 1990s, influential guidelines and reviews suggested that up to 85% of patients with low back pain could not be given a precise pathoanatomical diagnosis, and were therefore grouped as “nonspecific” or “mechanical” LBP. At the same time, the popularity of lumbar imaging exploded, despite repeated warnings that imaging abnormalities were common in people without pain.
This created a paradox:
- Many patients with severe pain were told that nothing serious was wrong because their MRI was “normal” or “age-related”.
- Others were offered surgery or focal interventions based solely on imaging findings that might be incidental, while the true pain generator remained unrecognised.
The turn of the century brought important correctives. Algorithmic interventional studies showed that if we systematically use medial branch blocks, discography, sacroiliac joint blocks and selective nerve root blocks, we can identify a concrete nociceptive source in a substantial proportion of chronic “nonspecific” low back pain patients. More recently, work on nociplastic pain and central sensitisation has underlined that in a significant subset, persistent pain cannot be fully explained by any single peripheral lesion.
In other words: structure does not equal symptom. Degeneration on imaging does not guarantee pain; nor does a structurally “normal” scan rule it out.
The central thesis of this article is that we can navigate this complexity with a simple but demanding framework based on two questions:
- WHERE is the pain generator?
- WHY is it painful in this particular person, at this point in time?
Everything that follows – history, examination, imaging, blocks, and choice of procedure – should serve these two questions.
The Diagnostic Framework: WHERE and WHY
WHERE: Identifying the Anatomical Pain Generator
The first step is to move away from “back pain” as a monolith and instead consider a finite list of potential pain generators:
- Intervertebral disc
- Internal disc disruption
- Disc prolapse
- Canal stenosis (disc + ligamentum flavum + facet hypertrophy)
- Facet joint complex
- Sacroiliac (SI) joint
- Muscles and fascia (myofascial pain)
- Ligaments and entheses
- Vertebral body (fracture, malignancy, endplate changes)
- Bursae
- Hip joint
- Deep gluteal structures (e.g., piriformis; “extraspinal sciatica”)
- Nerve root and spinal canal (radiculopathy, neurogenic claudication)
Each of these has characteristic clinical patterns, provocative manoeuvres, and referred pain maps, which we will examine later.
WHY: Understanding the Pathophysiological Mechanism
For any candidate structure, we must ask why it hurts now:
- Degenerative cascade and mechanical overload
- Acute or chronic inflammation
- Trauma or microtrauma
- Mechanical instability
- Neural compression or ischemia (e.g., canal stenosis)
- Enthesitis or inflammatory spondyloarthropathy
- Malignancy or infection
- Central sensitisation and nociplastic amplification of peripheral signals
This distinction is clinically crucial. Two patients with similar MRI findings – for example, a degenerated disc and mild facet arthropathy – may have completely different mechanisms: one predominantly nociceptive and mechanical, the other heavily driven by central sensitisation. They will respond differently to interventions.
Step 1: Always Screen for Red Flags
Before decoding mechanical, neuropathic, or nociplastic patterns, serious pathology must be excluded:
- Major trauma, suspected fracture, progressive deformity
- History of malignancy, unexplained weight loss
- Fever, immunosuppression, recent spinal infection risk
- Severe, relentless night pain
- Progressive neurological deficit
- Cauda equina features: saddle anaesthesia, new bladder/bowel dysfunction
When red flags are present, the algorithm shifts immediately to urgent imaging, labs, and referral (neurosurgery, orthopaedic spine, oncology, infectious disease) rather than nuanced mechanical reasoning.
Step 2: History – Listening for Pattern Language
Patients often describe pain in ways that map surprisingly well onto specific mechanisms if we listen carefully.
Discogenic Pattern
“My back pain is worse when I sit, especially while driving or at the computer. Bending forward or twisting makes it worse. Back pain is more than leg pain.”
Features:
- Axial back pain dominant
- Worsened by sitting, flexion, twisting
- Mechanical, often without true radicular symptoms
- Suggests internal disc disruption / degenerated disc
Radicular Pattern (Disc Prolapse)
“My leg pain is worse than my back pain. Sitting or lying down eases it. Standing and walking make the leg pain shoot down.”
Features:
- Leg-predominant pain in dermatomal distribution
- Classic S1 or L5 sciatica picture
- Positional relief with sitting/flexion
- Suggests nerve root compression from disc herniation
Stenosis Pattern (Canal Narrowing)
“After walking some distance, my legs feel heavy and painful. I have to sit or bend forward to get relief – leaning on a shopping cart helps.”
Features:
- Neurogenic claudication
- Bilateral or multi-dermatomal symptoms
- Relief with flexion (sitting, leaning forward), worse in extension
- Walking vs cycling paradox (can cycle longer because spine remains flexed)
- Suggests lumbar canal stenosis with neuro-ischemic mechanism
Facet Pattern
“It hurts when I arch backward or twist, like when I look behind while reversing the car. Sitting and bending forward feel better.”
Features:
- Predominant back pain with possible non-dermatomal leg referral
- Aggravated by extension, lateral bending, rotation
- Relieved by flexion and walking
- Localised paraspinal tenderness over facet joints
- Suggests facet joint arthropathy
Sacroiliac Joint Pattern
“I have deep pain in buttock. Sitting on hard surfaces is terrible, and prolonged standing also worsens it, but walking a bit can ease it.”
Features:
- Unilateral deep buttock or low back pain
- Often no neurological signs
- Aggravated by sitting, some by standing, certain transitions
- Positive cluster of SIJ provocation tests (FABER, sacral thrust, thigh thrust, compression, distraction)
Myofascial & Extraspinal Patterns
- Focal or regional muscular pain with trigger points
- Piriformis/deep gluteal pattern: buttock pain with sciatica-like radiation, but normal SLR, normal reflexes and dermatomes; pain worsened by hip internal rotation or FAIR test.
When we map the presenting complaint onto these archetypes, the WHERE begins to emerge.
Step 3: Physical Examination – A Focused Sequence
An efficient exam can be structured as follows:
- Observation & Gait
- Posture, sagittal/coronal balance, compensatory flexion, antalgic gait.
- Palpation
- Facet joints (1–2 cm lateral to midline), SI joints, paraspinal muscles, spinous processes, gluteal region, ligamentous insertions.
- Range of Motion
- Flexion, extension, lateral bending, rotation – and, importantly, which movements reproduce the patient’s familiar pain.
- Neurological Screening
- Myotomes, dermatomal sensation, reflexes, plantar response.
- Special Tests
- SLR, crossed SLR, femoral stretch test for nerve root involvement.
- Kemp’s/Stoop tests for stenosis.
- SIJ provocation test cluster.
- FAIR, Freiberg, Beatty tests for piriformis/deep gluteal syndrome.
The aim is to confirm or challenge the story suggested by the history. For example:
- Disc prolapse with radiculopathy: positive SLR/crossed SLR, dermatomal sensory changes, myotomal weakness, diminished reflex.
- Facet pattern: extension/rotation reproducing paraspinal pain without neuro deficit.
- SIJ pattern: multiple positive provocation tests increase specificity.
Step 4: Imaging – Answering a Question, Not Making a Diagnosis
MRI has revolutionised our ability to see the spine, but large meta-analyses in asymptomatic individuals show very high prevalence of “abnormalities”:
- Disc degeneration: ~37% in 20s → ~96% in 80s
- Disc bulge: ~30% in 20s → ~84% in 80s
- Protrusions and annular tears also rise steeply with age
This means that degenerative changes are the rule, not the exception, even in pain-free people. MRI should therefore be used to answer specific questions generated by the clinical evaluation:
- Does the imaging support suspected disc prolapse compressing the clinically involved nerve root?
- Is there clear central/foraminal stenosis consistent with the stenosis pattern?
- Are we missing fracture, malignancy, infection, or inflammatory sacroiliitis?
Imaging must be interpreted in context, not in isolation.
Step 5: Diagnostic Blocks – Powerful but Imperfect
Diagnostic blocks (facet joint/medial branch, SIJ, selective nerve root, sympathetic, etc.) can be extremely helpful in confirming or refuting a working diagnosis, especially before committing to ablative or surgical procedures.
However, they carry important limitations:
- Placebo and natural variation – 30–40% placebo response is not unusual; pain fluctuates naturally.
- Referred pain overlap – multiple generators may share the same referral zone; blocking one may unmask or mask another.
- Short vs long-term effects – a brief positive response does not guarantee lasting benefit from RFA or other “definitive” procedures.
- False positives – single uncontrolled blocks may have false-positive rates up to ~40% in some series.
To mitigate this:
- Use comparative local anaesthetic blocks (short- vs long-acting) where appropriate.
- Consider dual confirmatory blocks before destructive interventions when stakes are high.
- Always interpret block responses within the full clinical picture.
Case Lessons – When “WHERE” Is Not Enough Without “WHY”
Case 1: Sacroiliac Joint Pain in a Hidden Spondyloarthritis
A 42-year-old presented with unilateral buttock pain radiating to the posterior thigh and leg. SIJ tests were positive; MRI lumbar spine showed L5–S1 disc bulge with mild foraminal stenosis. Diagnostic SIJ injection produced ~80% pain relief, and RFA was planned.
Two months later, pain emerged in the opposite buttock, along with neck pain and heel pain. MRI of the SI joint revealed sacral edema, and the patient attributed all new symptoms to the procedure.
What went wrong?
The pain generator (SIJ) was correctly identified, but the underlying pathophysiology (WHY) – an inflammatory spondyloarthropathy – was missed. The SIJ was the victim, not the root cause. Without recognising the systemic inflammatory disease, local interventions alone were bound to fail or provide only transient benefit.
Lesson:
Do not stop at “WHERE”. Morning stiffness, alternating buttock pain, enthesitis, heel pain, and inflammatory features should prompt evaluation for SpA, with appropriate rheumatology involvement.
Case 2: “Facet Pain” in a Nociplastic Milieu
A 53-year-old male had 10 years of back pain (L>R) radiating to both thighs and legs, back > leg. Pain was aggravated by extension, rotation, and lateral bending; there was facet tenderness at L4–5 and L5–S1. MRI showed mild disc bulge and hypertrophied facets.
Medial branch blocks produced ~80% relief, so RFA was performed. At 6-week follow-up, the patient reported <30% improvement.
Retrospective review revealed:
- Diffuse tenderness
- Poor sleep, fatigue, cognitive symptoms
- Exaggerated pain even during LA injection
These features were consistent with central sensitisation and a regional nociplastic pain picture. The diagnostic block was likely a false positive, influenced by central mechanisms and expectation.
Lesson:
- Do not ignore systemic pain features and somatic symptoms.
- A dramatic response to LA in a highly sensitised patient may not mean that the facet joint is the dominant nociceptive driver.
- In chronic pain (>6 months) with widespread symptoms, nociplastic overlay must be considered, and interventions should be used sparingly and within a broader biopsychosocial plan.
Central Sensitisation and Nociplastic Low Back Pain
Nociplastic pain, as defined by current frameworks, refers to pain arising from altered nociception despite no clear evidence of ongoing tissue damage or disease sufficient to explain the intensity of pain.
Clinical clues include:
- Diffuse or widespread pain patterns
- Disproportionate pain to stimulus intensity
- Chronic fatigue and non-restorative sleep
- Allodynia and hyperalgesia
- Cognitive difficulties (“fibro fog”)
- Multiple tender points
- Poor or paradoxical response to purely peripheral interventions
These patients often have coexisting anxiety, depression, catastrophising, and fear-avoidance behaviours. For them, repeated injections and surgery are not only unhelpful but may reinforce a purely structural narrative that does not match their biology.
Management here must emphasise:
- Pain neuroscience education
- Graded activity and pacing
- Cognitive-behavioural and other psychological interventions
- Optimisation of sleep and mood
- Medications targeting central mechanisms when indicated
- Carefully selected regenerative or physical modalities within a multimodal programme
Why Interventions Fail – And How to Avoid Failure
Common reasons for interventional failure include:
- Targeting errors – Wrong level or inaccurate needle placement.
- Treating incidental findings – Intervening on degeneration that is not the main pain generator; failing to address multiple generators.
- Mechanism mismatch – Applying nociceptive procedures to predominantly neuropathic or nociplastic pain.
- Ignoring psychological and social context – Untreated distress, unrealistic expectations, poor adherence to rehab.
- Fragmented care – Isolated procedures without integration into a broader plan (physiotherapy, education, lifestyle).
Strategies to improve outcomes:
- Enhance diagnostic rigor: detailed history, thorough exam, contextual imaging, judicious blocks.
- Use confirmatory block protocols when uncertainty is high.
- Optimise patient selection: intervene only when a specific generator and mechanism are reasonably clear.
- Set realistic expectations: focus on meaningful improvement (e.g., 40–60% relief and functional gain) rather than “cure”.
- Integrate interventions into multimodal, longitudinal care, not as stand-alone solutions.
When NOT to Intervene
Sometimes the most important decision is restraint.
Avoid procedural interventions when:
- No clear convergence of history, exam, and imaging on a specific nociceptive source.
- Diagnostic blocks are negative or equivocal despite careful technique.
- Features strongly suggest predominantly nociplastic or somatoform pain without a defined peripheral driver.
- Risk–benefit ratio is unfavourable due to comorbidities, anatomy, or patient expectations.
In these scenarios, continuing to escalate procedural intensity may erode patient trust and expose them to risk without realistic benefit.
Beyond Blocks: Integrating the Full Therapeutic Toolbox
A decoded diagnosis should lead to mechanism-matched treatment, which may include:
- Pharmacological approaches: NSAIDs, neuropathic agents, muscle relaxants, regenerative agents, osteoporosis drugs, DMARDs/biologics where indicated.
- Physical and rehabilitative strategies: exercise therapy, manual therapy, posture and ergonomics, gait training, core stabilisation.
- Definitive treatments: targeted RFA, endoscopic discectomy, vertebroplasty/kyphoplasty, where clearly indicated and supported by diagnostics.
- Psychological interventions: CBT, ACT, mindfulness, addressing fear-avoidance and catastrophising.
- Traditional and adjunctive modalities: yoga, meditation, acupuncture, dry needling, when integrated sensibly into a broader plan.
The key is that each modality is chosen because it fits the identified WHERE and WHY, not simply because it is available.
Conclusion – Practicing Precision in Everyday Back Pain
“Decoding back pain” does not mean we will solve every case with mathematical precision. Uncertainty will always remain, and some patients will have genuinely mixed or evolving mechanisms.
However, if we:
- Systematically ask WHERE is the pain coming from?
- Diligently explore WHY this structure is painful now,
- Resist defaulting to “nonspecific LBP” as a final diagnosis,
- Use imaging and blocks as tools rather than oracles,
- Recognise nociplastic and centrally sensitised presentations early, and
- Reserve interventions for those with a clear nociceptive target and realistic expectations,
then our practice moves closer to genuine precision pain medicine.
In the end, decoding back pain is less about having exotic techniques and more about returning to disciplined clinical reasoning – supported, not replaced, by technology – and integrating that reasoning into compassionate, patient-centered care.
How to Cite This Lecture
You can cite this lecture in different formats. Please feel free to copy-paste the version you need.
Vancouver Style
Das G. Decoding Back Pain: Diagnostic Reasoning to Precision Interventions. Invited lecture presented at: 2nd Delhi Pain Summit, Global Pain School Annual Conference; 2025 Nov 9; New Delhi, India. DOI 10.5281/zenodo.17623858
APA Style (7th edition)
Das, G. (2025, November 9). Decoding Back Pain: Diagnostic Reasoning to Precision Interventions [Conference presentation]. 2nd Delhi Pain Summit, Global Pain School Annual Conference, New Delhi, India. DOI 10.5281/zenodo.17623858
BibTeX Entry (for reference managers)
@conference{Das2025DecodingBackPain,
author = {Gautam Das},
title = {Decoding Back Pain: Diagnostic Reasoning to Precision Interventions},
doi ={DOI 10.5281/zenodo.17623858}
booktitle = {2nd Delhi Pain Summit, Global Pain School Annual Conference},
year = {2025},
month = nov,
address = {New Delhi, India},
note = {Invited lecture}
}
About the Speaker
Dr. Gautam Das, MD, FIPP, FIAPM
Founder–Director, Daradia: The Pain Clinic, Kolkata, India
Dr. Gautam Das is a pioneer of interventional pain medicine in India and the Founder–Director of Daradia: The Pain Clinic, a dedicated centre for comprehensive pain management based in Kolkata. With more than 30 years of experience in pain medicine, he has trained hundreds of fellows and practicing physicians from India and abroad through Daradia’s fellowships, workshops, and online education programmes.
He is widely recognised for his work in fluoroscopy-guided and ultrasound-guided interventional procedures, evidence-based pain practice, and structured teaching in pain medicine. Dr. Das has authored and edited multiple textbooks and chapters on pain management, regularly publishes in peer-reviewed journals, and serves as invited faculty at national and international conferences.
Through Daradia, he is committed to combining clinical excellence, research, and teaching to improve the lives of patients living with chronic pain and to empower the next generation of pain physicians worldwide.
