Week 5 LBP (Moodle Version) PDF

Low Back Pain with Radiculopathy CMS 150 Learning Objectives Understand appropriate use of terminology to describe spinal pathology and pain Describe the assessment of a patient with low back pain, including identification of signs and symptoms that suggest lumbar radiculopathy Recognize red flags t...

Low Back Pain with Radiculopathy CMS 150 Learning Objectives Understand appropriate use of terminology to describe spinal pathology and pain Describe the assessment of a patient with low back pain, including identification of signs and symptoms that suggest lumbar radiculopathy Recognize red flags that would indicate need for imaging or referral Recognize the clinical features of an L5 radiculopathy and contrast them with those of a S1 radiculopathy In plain language discuss the natural history of intervertebral disc pathology to educate your patient about the diagnostic triage for low back pain Introduction radiculopathy (aka. pinched nerve) - injury or damage to nerve roots in the area they leave the spine that may result in pain, loss of sensation and/or motor function depending on the severity of symptoms acute low back pain (LBP) - up to 12 weeks chronic LBP - 3 months or greater lumbago - often refers to acute back pain or a strain, typically to either the quadratus lumborum muscle or the paraspinal muscles sciatica - often used to describe lumbosacral radiculopathy, more specifically pain distributed along the sciatic nerve (L4, L5, S1, S2, S3) Classifying Low Back Pain in Primary Care 1. a problem beyond the lumbar spine (e.g., kidney stones, hip pathology) 2. a serious disorder affecting the lumbar spine (e.g., epidural abscess, vertebral fracture, spondylolysis, spondylolisthesis) 3. low back pain occurring with radicular pain (e.g., related to intervertebral disc herniation) 4. neurogenic claudication (e.g., related to central spinal canal stenosis) 5. nonspecific low back pain - 90% of low back pain in primary care Constructing a Differential Diagnosis: Acute LBP 1. LBP due to disorders of the musculoskeletal structures - Nonspecific (mechanical) back pain - Specific MSK back pain: clear relationship between anatomic abnormalities seen on imaging and symptoms a. Lumbar radiculopathy due to herniated disc, osteophyte, facet hypertrophy, or neuroforaminal narrowing b. Spinal Stenosis c. Cauda equina syndrome 2. LBP due to systemic disease affecting the spine - Serious and emergent (requires specific and often rapid treatment) a. Neoplasms b. Infection - Serious but nonemergent (requires specific treatment but not urgently). a. Osteoporotic compression fracture b. Inflammatory arthritis 3. LBP due to visceral disease (serious, requires specific and rapid diagnosis and treatment) - could involve the pelvis, renal structures, GI structures, etc. Ddx: acute LBP with radiculopathy Mechanical Spinal fracture Lumbar disc herniation Cauda equina syndrome Piriformis syndrome, Iliotibial band syndrome Degenerative Spinal stenosis Spondylosis, Spondylolisthesis Facet arthropathy, Pseudoclaudication Inflammatory Sacroiliitis Greater trochanter bursitis Ankylosing spondylitis Oncologic Spinal neoplasms (most commonly metastatic) Infectious Vertebral lesion (infection, e.g. epidural abscess) red flag findings (AAFP, 2008) Presenting Symptoms Medical History Fecal incontinence or loss of bowel control Immunosuppression, recent infection Urinary retention or loss of bladder control Chronic steroid use Saddle anesthesia Osteoporosis Unexplained fever Significant trauma, at any age Unexplained weight loss Mild trauma, older than 50yrs Focal neurological deficit, progressive or disabling symptoms History of cancer No improvement after 6 weeks of conservative management IV drug use Diagnostic Accuracy of Individual Red Flag Findings (JBJS, 2018) Findings Sensitivity (%) LR + LR - 74 / 71.7 1.1 / 1.06 0.79 / 0.87 Recent loss of bladder control (cauda equina syndrome) 22.2 2.31 0.86 Recent loss of bowel control (cauda equina syndrome) 13.9 2.78 0.91 Unexplained weight loss (malignancy) 8.2 1.87 0.96 Personal history of Cancer (malignancy) 32 7.25 0.71 Fever, chills or sweating (infection) 11.7 1.71 0.95 Recent infection (infection) 24.2 9.31 0.78 Age > 50 yrs (fracture / malignancy) Diagnostic Accuracy of Combined Red Flag Findings (JBJS, 2018) Findings Sensitivity (%) LR + LR - Trauma + Age > 50 yrs (fracture) 14.8 2.54 0.90 Trauma + Age > 70 yrs (fracture) 5.2 4.35 0.96 Recent loss of bowel + bladder control (cauda equina syndrome) 8.3 3.0 0.94 Unexplained weight loss + PHx Cancer (malignancy) 2.5 10.25 0.98 Fever, chills or sweating + Recent infection (infection) 7.5 13.15 0.93 Cauda Equina Syndrome - compression and disruption of function to cauda equina (namely L3-L5 nerve roots), most commonly due to lumbar disc herniation (45% of cases, but only approx. 3% of lumbar disc hernations) incidence 1:33,000-100,000, approx. 1000 new cases per year in US classical symptoms: - new urinary retention or overflow incontinence, fecal incontinence - progressive motor or sensory loss - saddle anesthesia, lower motor neuron weakness, significant deficits that encompass multiple nerve roots Diagnosis: imaging (MRI) is diagnostic gold standard Urgent ER referral; requires surgical decompression within 24-48hrs Spinal Malignancy: Metastases - the most commonly tumours of the spine are metastases of other primary cancers: breast (21%), lung (19%), prostate (7.5%), renal (5%), gastrointestinal (4.5%), and thyroid (2.5%) personal history of cancer back pain (deep, aching), unexplained weight loss; possibly sensory loss, weakness or radiculopathy (with tumour growth) Diagnosis: imaging (xray or MRI) - blood work (incl CBC) and symptoms depend on type of primary cancer Urgent referral back to oncologist or palliative care Vertebral Fracture - a break in one or more spinal vertebrae that can result from trauma and metastatic disease but, in most cases, are the result of osteoporosis (at T11 - L2) low bone density (smoking, alcohol, anorexia, medications, Vitamin D deficiency), female > 50 yrs, prolonged use of corticosteroids, trauma/fall, personal history of vertebral fracture back pain (acute or chronic, localized) agg. with standing or walking, rarely radiculopathy Diagnosis: imaging (CT) is diagnostic - tenderness over affected vertebra(e) Urgent referral for imaging, may require surgical intervention Vertebral Infection: Osteomyelitis - the most common vertebral infection (particularly the vertebral body), often caused by hematogenous spread of Staphylococcus aureus rare (4.8 cases per 100,000 in US), approx. 3-5% of all cases of osteomyelitis recent spinal procedure/surgery (with 12 months), recent infection, wound in spinal region, Hx IV drug use, immunosuppression (incl. advanced age, diabetes, long term corticosteroid use, malnutrition, malignancy) back pain (as infection progresses, pain localizes), fever (in 35-60% of cases); sensory loss, weakness or radiculopathy (in 33% of cases) Diagnosis: imaging (MRI) is preferred - CBC often normal, ESR elevated, CRP elevated, blood cultures Urgent ER referral; requires antibiotic therapy (IV and oral) (CMAJ, 2017) LBP with Radiculopathy: Etiology L4-L5 (L5 nerve root) and L5-S1 (S1 nerve root) are most susceptible to injury - particularly flexible part of lumbar spine - bears more impact than thoracic and cervical spine L5 S1 Approx. 90% of compressive lumbosacral radiculopathies occur at either of these levels. LBP with Radiculopathy: Epidemiology Lumbosacral radiculopathy is common: 3 - 5% of population male (40yr+) > female (50yr+) - 3:2 L5 radiculopathy is the single most common lumbar radiculopathy Pain Experience: often described as tingling, electric, burning or sharp Paresthesia: 63 to 72% of patients Radiation of pain into lower limb: 35% Numbness (anesthesia): 27% Muscle weakness: present in up to 37% Absent Ankle Reflexes: 40% Absent Knee Reflexes: 18% LBP with Radiculopathy: Risk Factors Social History: Repetitive lifting and twisting motions Chronic overloading of disc: driving occupations, Heavy industry work, Military Lifestyle: smoking, overweight, sedentary Medical History: Prior trauma (fall, motor vehicle accident (MVA)) Multiple pregnancies History of back pain Chronic cough LBP with Radiculopathy: History Intake Site: ask about the location of the back pain Onset: How and when the back pain developed Pain may follow a heavy lifting, twisting or straining episode or repetitive stress trauma Quality: pain is often described as throbbing, aching, sharp, dull, burning, pressure, numbness, tingling, or shooting Radiation: assess dermatomal distribution Time Course: consider how the back pain changed over time LBP with Radiculopathy: History Intake Severity of pain experience: Scale of 1-10 Pain is typically worse with: Increased intradiscal pressure Valsalva, weight bearing, standing, walking, sitting for prolonged periods Pressure increases: Coughing, sneezing, straining (bowel movement) Forward flexion of the lumbar spine Pain is typically better with: Extension of the lumbar spine Recumbent position (knees flexed) LBP with Radiculopathy: History Intake Associated Signs and Symptoms : Motor or sensory disturbances: suggestive of nerve root or spinal cord compression Ask specifically about saddle anaesthesia if cauda equina syndrome is a possibility. Urinary retention or incontinence: typical features of cauda equina syndrome. Hematuria (blood in urine): may occur secondary to back trauma (due to renal injury), urinary tract infection and renal tract malignancy. LBP with Radiculopathy: History Intake Associated Signs and Symptoms: Fever: typically associated with urinary tract infection, pneumonia and discitis. Malaise: associated with a wide range of pathology but in the context of back pain consider discitis or malignancy. Weight loss: associated with malignancy. Early morning stiffness: associated with inflammatory arthritis (e.g. rheumatoid arthritis, ankylosing spondylitis). Muscular spasms: may be associated with spinal fracture or primary muscular injury. LBP with Radiculopathy: History Intake Key Medical History: History of malignancy Recent bacterial infections Recent history of epidural or spinal surgical procedures Medications: history of or current corticosteroid use Patients should also be evaluated for social or psychologic distress that may be contributing. Assess ability to function in daily life. Disc Hernation - displacement of intervertebral disc material (nucleus pulposus or annulus fibrosis) beyond the intervertebral disc space 1-3% of patients with acute LBP; age 30-40, male: female 2:1 acute-chronic pain, paresthesia, sensory change, loss of strength or reflexes (depends on affected nerve root) Diagnosis: SLR + Hancock rule - Straight Leg Raise (SLR) test - ipsilateral leg pain at less than 45-60o is positive for lumbar disc herniation - Well Leg Raise (WLR, aka. crossed SLR) test - reproduction of contralateral pain at less than 45o is positive for lumbar disc herniation 85-90% experience relief within 6-12 weeks without treatment Patterns of Disc Herniation Bulging Disc Loss/damage of annular fibers allows the nucleus pulposus to shift without herniation Associated with trauma, repetitive stress or aging Prognosis (without treatment): Regression: 13% Complete Disappearance: 11% image from NEJM, 2016, doi: 10.1056/NEJMcp1512658 Patterns of Disc Herniation Herniated Disc – Protrusion (Prolapse) Focal distension of the disc Annulus fibrosis remains intact Prognosis (without treatment): Regression: 41% Complete Disappearance: 0% image from NEJM, 2016, doi: 10.1056/NEJMcp1512658 Patterns of Disc Herniation Herniated Disc – Extrusion Nucleus palposus breaks through the annulus fibrosis Remains in the disc Prognosis (without treatment): Regression: 70% Complete Disappearance: 15% image from NEJM, 2016, doi: 10.1056/NEJMcp1512658 Patterns of Disc Herniation Herniated Disc – Sequestration Nucleus palposus breaks through the annulus fibrosis and is displaced from the site of extrusion. Considered a subtype of of ‘‘extruded disc’’ Prognosis (without treatment): Regression: 96% Complete Disappearance: 43% image from NEJM, 2016, doi: 10.1056/NEJMcp1512658 Physical Exam Findings associated with Lumbar Disc Hernation Findings Sensitivity (%) LR + LR - Weak ankle dorsiflexion 54 4.9 0.5 Calf wasting* 29 5.2 0.8 Leg sensation abnormal 16 NS NS Abnormal ankle reflex 48 4.3 0.6 + Straight Leg Raise (SLR) test 73 - 98 NS 0.2 + Crossed SLR test 23 - 43 4.3 0.8 NS = not significant * Calf wasting may take 4 - 6 weeks to develop and may represent chronic impingement or severe, progressive neuromotor dysfunction (AAFP, 2008) Straight Leg Raise (SLR) test (image: orthobullets) Hancock Rule: Clinical Prediction Rule for Lumbar Disc Herniation The diagnostic accuracy of multiple neurologic findings improves clinician ability to determine level of disc herniation if at least 3 of 4 findings are in concordance with a specific nerve root: - dermatomal pain location - sensory deficit - reduced reflex - motor weakness Findings Sensitivity (%) LR+ LR- score ≥ 3 for L3/L4 disc herniation 50 5.0 0.56 score ≥ 3 for L4/L5 disc herniation 37 2.18 0.76 score ≥ 3 for L5/S1 disc herniation 28 4.67 0.77 (Spine, 2011) Neurologic examinations dermatome test myotome test reflex (AAFP, 2008) L2, L3, and L4 Radiculopathy Distribution of Pain: L2, L3, and L4 lumbar radiculopathies are considered a group Marked overlap of the innervation of the anterior thigh muscles An acute injury in the distribution of L2, L3, and L4 will most commonly present with Radiating back pain to the anterior aspect of the thigh, which may progress into their knee, and possibly radiate to the medial aspect of the lower leg, into the foot. Lee, M. W. L., McPhee, R. W., & Stringer, M. D. (2008). An evidence‐based approach to human dermatomes. Clinical Anatomy, 21(5), 363–373. doi:10.1002/ca.20636 L2,L3, and L4 Radiculopathy Physical Exam : Motor Weakness: knee extension, hip adduction, and or hip flexion. Paresthesia/Sensory Changes: anterior thigh along the area of pain Absent Reflexes: patellar reflex (L4) Activities that can make the symptoms worse include coughing, leg straightening, or sneezing. Findings Sensitivity (%) LR + LR - Weak knee extension (L3 or L4) 38-48 4.0 0.6 Asymmetric quad reflex (L3 or L4) 29-56 8.5 0.7 statistics from: Evidence-based physical diagnosis. McGee, Steven R. 4th Edition. p 754. L5 Radiculopathy Distribution of Pain: In L5 radiculopathy, patients will often complain of acute back pain, which radiates down the lateral leg into the foot. Lee, M. W. L., McPhee, R. W., & Stringer, M. D. (2008). An evidence‐based approach to human dermatomes. Clinical Anatomy, 21(5), 363–373. doi:10.1002/ca.20636 L5 Radiculopathy Physical Exam: Motor Weakness: Big toe extension (extensor hallucis longus) Foot eversion & inversion Ankle dorsiflexion. Hip abduction (gluteus minimus and medius) Paresthesia/Sensory Changes: Lateral thigh, lateral lower leg, dorsum of the foot Absent Reflexes: none Atrophy (chronic): extensor digitorum brevis and tibialis anterior. L5 Radiculopathy Findings Sensitivity (%) LR + LR - Weak hallux extension 12 - 62 1.7 0.7 Weak ankle dorsiflexion 37 - 62 NS NS Sensory loss in L5 distribution 20 - 52 3.1 0.8 Asymmetric medial hamstring reflex 57 6.2 0.5 NS = not significant statistics from: Evidence-based physical diagnosis. McGee, Steven R. 4th Edition. p 754. S1 Radiculopathy Distribution of Pain : S1 radiculopathy will cause radiation of sacral or buttock pain into the posterior aspect of the patient's leg, into the foot, or the perineum. Physical Exam: Motor Weakness: plantar flexion Paresthesia/Sensory Changes: sole, lateral foot and ankle, fourth and fifth toes Absent Reflexes: ankle reflex (S1) Lee, M. W. L., McPhee, R. W., & Stringer, M. D. (2008). An evidence‐based approach to human dermatomes. Clinical Anatomy, 21(5), 363–373. doi:10.1002/ca.20636 S1 Radiculopathy Findings Sensitivity (%) LR + LR - 26 - 45 NS 0.7 43 2.4 0.7 Sensory loss in S1 distribution 32 - 49 2.4 0.7 Asymmetric achilles reflex 45 - 91 2.7 0.5 Weak ankle plantar flexion Ipsilateral calf wasting NS = not significant statistics from: Evidence-based physical diagnosis. McGee, Steven R. 4th Edition. p 754. Evidence-Based Physical Exam Evidence-based physical diagnosis / Steven McGee. McGee, Steven R. 4th Edition. Page 754. Serious disorders affecting the Lumbar Spine - - spondylosis: an umbrella term for age-related degeneration of the spinal column (often involves degenerative disc disease and facet arthropathy) spinal stenosis: narrowing of the spinal canal, neural foramen and lateral recess which can lead to compression of the nerve roots and neurogenic claudication - most commonly due to spinal osteoarthritis (degeneration of the vertebral bodies, joints and foramina due to “wear and tear”) spondylolysis: weakness or stress fracture through the pars interarticularis spondylolisthesis: the slippage of one vertebral body with respect to the adjacent vertebral body Spinal Stenosis - narrowing of the spinal canal, neural foramen and lateral recess which can lead to compression of the nerve roots and neurogenic claudication 3% with mechanical low back pain (LBP), 19.4% aged 60-69 years LBP with B/L lower extremity pain, numbness or loss of strength (depends on affected nerve root) agg. by ambulation, standing and lumbar extension - neurogenic claudication: pain/discomfrot with walking or prolonged standing that radiates into one or both lower extremities (relieved by rest/ sitting, lumbar flexion) Diagnosis: imaging is diagnostic - pain elicited with passive and active lumbar extension, neurologic exam (typically normal), pedal pulses symmetrical approx. 19% of patients who had an initial surgery eventually repeat surgery Spinal Stenosis (images from: OrthoInfo) Spinal Stenosis (images from: JAMA, 2009) Subjective + Physical Findings associated with Spinal Stenosis Findings Sensitivity (%) LR + LR - No pain when seated 47 7.4 0.57 Unexplained urinary disturbance 14 6.9 0.88 Symptoms improve with bend forward 52 6.4 0.52 Bilateral buttock or leg pain 51 6.3 0.54 Neurogenic claudication 82 3.7 0.23 Wide-based gait 42 13 0.60 Abnormal rhomberg test 40 4.2 0.67 Symptoms induced with bend forward 18 0.48 1.3 (JAMA, 2009) History or Exam Characteristic Risk Score Age 60 - 70 years (> 70 years) 1 (2) Prediction Rule for Dx: Spinal Stenosis 1 interpretation (-2 to 17): Neurogenic claudication 3 Symptom exacerbation when standing 2 score ≥ 7 - increased likelihood of lumbar spinal stenosis Symptoms improve with bend forward 3 Symptoms induced by bend forward -1 Findings Sens LR+ LR- Symptoms induced by bend backward 1 score ≥ 7 93% 3.3 Good peripheral artery circulation 3 Abnormal achilles tendon reflex 1 SLR positive for pain reproduction -2 Absence of diabetes 0.1 (JAMA, 2009) Spondylolysis - a unilateral or bilateral defect through the pars interarticularis (most commonly affects L5, 90%) 6-18% population (14+); up to 50% young athletes (male:female, 2:1) risk associated with excessive lumbar lordosis, genetics (fHx) asymptomatic (90% of patients); insidious onset, recurrent axial low back pain exacerbated with activity or lumbar hyperextension, +/- radiculopathy Diagnosis: imaging is diagnostic - increased lumbar lordosis, tight hamstrings, reduced lumbar ROM (esp. extension), tenderness overlying fracture site at diagnosis, 50-75% of bilateral spondylolysis will have spondylolisthesis X-ray showing pars fracture in L5 images from: OrthoInfo Spondylolisthesis - the slippage of one vertebral body with respect to the adjacent vertebral body from degenerative, lytic (isthmic), traumatic, dysplastic, or pathologic causes (most commonly anterior translation of L5 on S1) 3-4% of patients with mechanical LBP adults, female > male, obesity, fHx (spondylolisthesis, scoliosis, spina bifida) intermittent and localized low back pain that radiates into buttock or posterior thigh; paresthesia, sensory change, loss of strength or reflexes (depends on affected nerve root) Diagnosis: imaging is diagnostic (used to grade as well) - pain elicited with lumbar flexion and extension, tenderness over affected vertebral segment 75% are grade I and typically stable in older patients, may progress in puberty Spondylolithesis - Grading Meyerding’s Classification, image from: ONZ Spine Spondylolithesis xrays of lytic (isthmic) (OrthoInfo) and degenerative spondylolisthesis (OrthoInfo) Evaluation - Imaging Initial imaging is not indicated in the majority of patients with low back pain. - due to very high prevalence of abnormal neuroimaging findings even in asymptomatic patients - conservative management for 6 weeks is typically recommended before considering imaging (radiography, MRI, CT) - UNLESS presenting with severe symptom intensity (causing diability) or red flag findings for conditions that require timely diagnosis to prevent serious consequences (e.g. cauda equina syndrome, malignancy, fracture and infection) Imaging Options MRI: considered the best initial examination Provides axial as well as sagittal views Demonstrates discs, ligaments, nerve roots, and epidural fat, as well as the shape and size of the spinal canal. MRI is more sensitive and specific than plain radiographs for the detection of spinal infection and malignancy. CT with contrast: used in patients who cannot undergo MRI Contraindications to MRI: pacemaker or defibrillator device Plain Radiographs: those who have risk factors for malignancy or fractures Acute Low Back Pain Considerations for Imaging Signs or symptoms of cauda equina syndrome (new urinary retention, fecal incontinence, or saddle anesthesia) OR Significant neurologic deficits (progressive motor weakness or significant motor deficits not localized to a single unilateral nerve root) Current or recent cancer history (other than nonmelanoma skin cancer) particularly breast, prostate, lung, thyroid, renal + multiple myeloma NO Moderate to high risk for cancer (multiple risk factors/symptoms, history of cancer, strong clinical suspicion) YES NO Plain Radiography plus ESR (or CRP) NO YES YES Emergency MRI and specialist consultation Discuss choice of imaging study with patient’s oncologist xray suggests possible cancer xray normal, ESR high (or CRP) Evaluate for Malignancy MRI NO Signs, symptoms, risk factors for spinal infection (e.g epidural abscess or osteomyelitis): Objective fever; Current immunosuppression, hemodialysis Current or recent bacteremia, injection drug use, endocarditis, invasive epidural/spinal procedure YES NO Level of suspicion for spinal infection algorithm from UpToDate High Low MRI ESR and/or CRP Elev MRI Risk for vertebral compression fracture (advanced age, history of prolonged systemic steroids, significant trauma, mild trauma with history of risk factors for osteoporosis) YES Plain Radiography NO Other patients (LBP without other worrisome features Conservative therapy for 4-6 week. and low risk for cancer, spinal infection, or progressive If no improvement in symptoms, neurologic impairment assess for subacute LBP Management There are three categories of radicular symptoms and signs: Mild radiculopathy is considered a sensory loss and pain without motor deficits Moderate radiculopathy is the sensory loss or pain with mild motor deficits Severe radiculopathy is considered sensory loss and pain with marked motor deficits. Management of patients underlying symptoms will depend on the severity of the radiculopathy, namely severe radiculopathy increases need for earlier imaging. Prognosis Most cases of lumbosacral radiculopathy are self-limited. Spontaneous improvement is very common without treatment. Counseling is crucial for patients with radicular symptoms since most cases are mild and will resolve within six weeks. It is vital to discuss weight loss reduction, as the vast majority of these patients will have an elevated body mass index. Concerns arise when a patient's symptoms worsen or are severe. Severe symptoms warrant further imaging and/or emergent surgical intervention. Patient Education Disease education: - Provide reassurance: - low likelihood of serious pathology - most cases are self-limited and resolve with conservative management in 6-8 weeks - Stay active (moderate level) and return to normal activities as soon as possible; avoid bed rest and aggravating movements - Pain management includes nonpharmacologic (physiotherapy) and pharmacologic options What they need to look out for: - Symptoms persisting for over six weeks may benefit from additional interventions (e.g. injections) - Red Flag symptoms that warrant an immediate emergent evaluation and potential surgical consultation Complications Lumbar radiculopathy is often self-limited but can be extremely painful. An immediate complication that can arise from acute radicular pain is the loss of function and decreased quality of life. Emergent complications include cauda equina syndrome and severe lumbar radiculopathy. Both of these complications often require emergent surgical decompression. Patients who do not improve within the six to twelve weeks following the onset of pain can develop chronic pain. Slowly progressing radicular symptoms can eventually lead to muscle atrophy as the nerves innervating the lower extremity musculature are affected. Deconditioning can occur over time.