A Concise Approach to Low Back Pain By : Hieder A`ala 601 MUST UNIVERSITY
Prevalence 60-80% of people will have LBP sometime in their lives. 30% are referred to Ortho; 3% admitted; 0.5% operated. 90% LBP resolves in 6w, 75% may experience symptoms & disability one year after initial consultation. The prevalence of LBP has changed little over the years, but the associated disability has increased four fold In the UK certified incapacity for LBP was 120 milion days in 1996 14 million consultations annually. Overall cost of LBP was £6 billion
Why take it seriously? Acute low back pain is often recurrent, Predisposes to chronic pain and disability A warning of potential future trouble Impacts on the quality of life Lost days of productivity Huge cost of incapacity payouts Enormous burden on healthcare costs when chronic
Types of Back Pain: Discogenic back pain • annulus fibrosus when it is stretched with a bulging disc • Outer1/3 has sensory innervation, • radial fissuring is associated with painful discs Radicular back pain • pain extending to the buttock and/or leg • disc herniation , spinal stenosis or intraspinal pathology Psychogenic back pain • must exclude organic pathology
Types of Back Pain Facet-joint pain • Studies of provocative intra-articular injection techniques demonstrated local and referred pain into the lower extremity from the lumbar facets. • The fibrous capsule of the facet joint contains encapsulated, unencapsulated, and free nerve endings. Sacroiliac pain • variable local and referred pain patterns into regions of the buttock, lower lumbar area, lower extremity, and groin. Muscular pain (myofascial pain ) • MP is characterized by muscles that are in a shortened or contracted state, with increased tone and stiffness, and that contain trigger points
Types of Back Pain Viscerogenic Back Pain • may be derived from disorders of the kidneys or the pelvic viscera, lesions of the lesser sac, and retroperitoneal tumors • Backache is rarely the sole symptom of visceral disease. Vascular Back Pain • Abdominal aortic aneurysms or peripheral vascular disease (PVD) may give rise to backache or symptoms resembling sciatica • Intermittent claudication intermittent pain in the calf”associated with PVD may on occasion mimic sciatic pain produced by root irritation, but the history of specific aggravation by walking and relief by standing still will make the clinician look for signs of peripheral vascular insufficiency.
Three syndromes are recognized in which spinal disorders cause both back and neurologic dysfunction. Examples are : 1. Herniated disc causing a single nerve root compression (leg pain > back pain). – Clinical features include positive straight leg-raising test and radicular pain in the limb disproportionate to pain in the spine. Loss of strength, reflex, and sensation occurs in the territory of the compressed root. 2. Lateral recess syndrome (leg pain ≥back pain). Single or multiple nerve roots on one or both sides become compressed. Pain in the limb is usually equal to or greater than that in the spine. Symptoms are brought on by either walking or standing and are relieved with sitting. Testing by straight leg raising may be negative. 3. Spinal stenosis (leg pain < back pain). Multiple nerve roots are involved, and the pain in the spine is significantly greater than that in the limb. Symptoms develop with standing or walking. Impairment in bowel and bladder dysfunction as well as sexual dysfunction may occur.
History taking…. Past history of similar symptoms, course of treatment, and response Onset of current episode, mechanism of injury, and initial location of pain Current location and character of pain, associated symptoms, and influencing factors Pain status: improving, deteriorating, or plateaued? Red flags (eg, neurologic deficits, bowel or bladder dysfunction, systemic illness) Physical and functional impairment due to pain
Identify complexities in management Involvement with a disability compensation claim, Symptom magnification, drug-seeking behaviour, past history of chronic pain, and psychosocial stressors. Past medical history, family history, health habits, exercise habits, social and occupational history Dependency, sleeplessness, and emotional distress resulting from or contributing to the pain.
Points to note….. Lumbar spine tolerates a higher degree of stenosis than the cervical or thoracic region The discs, facet joints & capsules, ligamentum flavum are affected by degenerative processes. The dimensions of the spinal canal and foramen are . influenced by dynamic and postural factors The foramina decrease in size while the nerve roots increase in diameter as you move down the spine. Thus the lumbar spine is most commonly affected
Points to note…..The objective of a detailed history andthorough clinical examination are toavoid missing cauda equinasyndrome…The MPS case book has highlightedthe following points ( slides 9 -14)
What is Cauda Equina Syndrome? Cauda Equina Syndrome is a collection of signs and symptoms resulting from compression of the bundle of nerve roots emerging from the end of the spinal cord below the 1st lumbar vertebra. The classic syndrome is characterised by severe LBP with bilateral sciatica associated with saddle anaesthesia, urinary retention and bowel dysfunction.
Cauda equina syndrome - Red flags Severe low back pain with bilateral or unilateral sciatica Bladder or bowel dysfunction Anaesthesia or paresthesia in perineal region or buttocks Significant lower limb weakness Gait disturbances Sexual dysfunction
Types of onsetThe onset can be either acute or chronic…. Acute onset: of severe back pain, sciatica, urinary disturbances, motor weakness in the lower extremities and saddle anaesthesia or hypoesthesia in patient with no previous history of LBP More insidious onset characterised by recurrent episodes of backache over a few weeks to years followed by – gradual onset of sciatica and – motor and sensory loss, – with bowel and bladder dysfunction developing over a few days to several weeks.
Vital questions for patients with LBP ‘Have you noticed any numbness or strange sensations around your buttocks or between your legs? For example, does the toilet paper feel normal when you wipe your bottom?’ ‘Has your bladder been working normally? Can you tell when it’s full? Have you had any loss of control (accidents), or difficulty passing urine? Or have you felt that you want to go all the time?’ ‘Have you experienced any unusual problems with your bowels lately?’ ‘Have you noticed any changes in sexual function
Physical examination The severity depends on the location and the degree of compression. The levels most often affected are L4/L5 and L5/S1 Few patients actually present with a ‘classical’ set of signs and symptoms which should be specifically elicited Neurological examination should include testing for sensation, motor weakness and diminished reflexes
Spinal Stenosis: Pathophysiology Narrowing of the central canal and/or intervertebral foramina is due to: – Posterior disc bulging – bone spur formation – facet joint enlargement – hypertrophy of ligamentum flavum Natural history – Symptoms unchanged in 60-70% – Worse in 15-20% – Improved in 15-20%
Incidence of spinal stenosis on imaging is very high in the elderly population but only a fraction manifest the true symptoms Central stenosis: – increased unsteadiness or loss of balance – they walk stooped forward – Rarely - urinary incontinence & cauda equina syndrome – Physical examination can be unimpressive Foramenal stenosis: – Radicular signs from narrowing of the lateral recess or the neural foramen.
Discogenic pain Normal discs have sensory nerve endings in the outer 1/3 of the annulus Disc stimulation studies normal discs do not cause pain Disc stimulation is specific for painful discs and is in particular for radial annular tears Reproduction of pain co-relates with the degree of fissuring of the disc
Spondylo-lysis & listhesis Caused by a defect in the pars interarticularis Usually a fatigue fracture from repetitive hyperextension stresses (gymnasts) most common cause of LBP in adolescents plain x-rays demonstrate 80% of lesions oblique views - additional 15% picked up - Scottie dog sign (Lachapelle) CT - may miss fracture
Examination Posture – change in lumbar lordosis, scoliosis Range of motion – flexion,extension, lateral flexion SLR – seated & supine, sciatic nerve stretch test Presence of paraspinal muscle spasm, trigger points Tender areas –facets, sacro-iliac joints Neurological deficit – – Dermatomal hypo/hyperaesthesia – Ability to rise from squatting position (L4),walk on heels(L5), walk on tip-toes (S1) – Tendon reflexes – knee jerk(L4 root), ankle jerk(S1 root)
Evaluation Consider the physical & psychological aspects Degree of interference with desired & necessary activity Response to past treatments Co-existing complaints & medical diseases Evaluation of functional capacity – walk, stand, sit, climb stairs
Investigations X-rays: bone spurs, decreased disc height and facet hypertrophy in older patients. CT: more accurate and detailed picture of the bony anatomy – less accurate than MRI in estimating the degree of compromise of the soft tissue elements. – thus can underestimate the degree of stenosis – spinal canal < 10mm AP diameter = Absolute Stenosis MRI: (without gadolinium) – currently represents the "gold standard" in the evaluation of central stenosis. – allows visualization of disc, neural elements, ligamentum flavum & thecal sac
Pitfalls Upto 80% of patients cannot be given a definite diagnosis because of the poor co-relation between symptoms, clinical findings and imaging results High incidence of false negatives on imaging No diagnostic lab tests that reveal the cause of LBP Outcome of treatment difficult to quantify and predict
Surgical treatment Urgent operations are required in cases like progressive neural deficit, cauda equine syndrome, lumbar trauma with instability, tumors and infections (the red flags ) . The non-urgent operation operation is for persistent pain that does not respond to proper conservative measures or mechanical LBP with instability
Operative ResultsOperative results can be variable as….. not all stenotic sites necessarily cause symptoms, therefore selecting decompression levels can be difficult insufficient decompression regrowth of resected tissue & scarring Multi-level involvement does not do well due to post- op instability (should consider fusion, but very invasive) Careful attention to patient selection and meticulous operative planning are important in optimizing surgical outcome.