Week 09 - Low Back Pain Mood (Moodle Version) - update June 2023 (1).pdf

Return of Low Back Pain Nonspecific Low Back Pain CMS 150 Learning Objectives Provide an overview for your patient about the diagnostic triage for low back pain with reference to the likelihood of serious disease vs radicular and non-specific presentations. Describe at the patient level speci...

Return of Low Back Pain Nonspecific Low Back Pain CMS 150 Learning Objectives Provide an overview for your patient about the diagnostic triage for low back pain with reference to the likelihood of serious disease vs radicular and non-specific presentations. Describe at the patient level specific spinal and non-spinal causes of low- back pain and specify the classification based on duration (e.g. acute) Identify alerting clinical symptoms that require immediate referral or investigation. Describe the rationale for why pursuit of a specific structural pain generator (e.g. a structural abnormality) is often problematic, and that in most cases low-back pain should be considered nonspecific. Describe to your patient pertinent issues related to the appropriate use of diagnostic imaging in low-back pain. When indicated, recommend, administer, and interpret appropriate physical, laboratory and imaging diagnostic examinations and procedures to establish a comprehensive assessment. Nonspecific Low Back Pain Definition: Low back pain is a symptom rather than a disease in that it can have many causes The most common form of low back pain is non-specific low back pain. This term is used when the pathoanatomical cause of the pain cannot be determined. Accounts for 90% of cases of LBP in primary care setting Leading contributor to disease burden worldwide Time Course: Acute: < 6 weeks Subacute: 6-12 weeks Chronic: > 12 weeks Epidemiology 49-90% of people in developed countries will experience at least one episode of low back pain during their lifetime Peak incidence occurring between ages 25-64 – usually resolves within 2 weeks but symptoms linger up to 2 months 24-80% will experience further episode within a year and 3/4 will have reoccurrence at some point in their lives 2-7% develop chronic LBP Management is complex and costly – 40% of patient with back pain seek help from a healthcare provider. 65% are managed by GPs and they are the sole provider. Risk Factors Physical Factors: Prolonged standing, walking Lifting heavy weights Unhealthy Lifestyle: Smoking Obesity Psychological Factors: Depression Job dissatisfaction Prior episode of low back pain Etiology 90% of back pain cases are non-specific Of the patients with low back pain in primary care about… 4% compression fracture 3% spinal stenosis 2% visceral disease 0.7% a tumour or metastasises 0.01% an infection Constructing the Differential Diagnosis (1) Back Pain due to disorders of the musculoskeletal MOST LIKELY structures 1. Nonspecific (mechanical) back pain 2. 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 (Red Flag & Emergent) Constructing the Differential Diagnosis (2) Back pain due to systemic disease affecting the spine 1. Serious and emergent (requires specific and often rapid treatment) But.. we have to consider the red a. Neoplasia (Cancer) b. Infection flags before mechanical low back pain 2. Serious but nonemergent (requires specific treatment but is our primary working diagnosis not urgently. a. Osteoporotic compression regardless fracture of the (will learn in BMS 150 Lab) likelihood b. Inflammatory arthritis (will learn in BMS 150) (3) Back pain due to visceral disease (serious, requires specific and rapid diagnosis and treatment) 1. Could involve the pelvis, renal structures, GI structures and more! Assessment Identify the source of the pain Consider pain mechanism and location Take a structured pain history - consider one of the following strategies: OPQRST – Onset, Provoking/Palliating, Quality of pain, Region/Radiation, Severity, Timing/Treatment. AAA - Alleviating/aggravating factors, Associated symptoms, Attributions/adaptation. Consider assessment for mood disorder and substance use disorder. GAD-7; HAM-D Scales etc. Assess early for Red Flags and Yellow Flags History of Presenting Illness History: Onset of back pain Location, and if pain is unilateral/bilateral Quality of pain (dull) Radiation of pain (none) Alleviating and aggravating factors Medications/therapies that have been attempted/are successful to relieve the pain Associated trauma or overuse injury Sensory loss (none) Paresthesia (none) History of Presenting Illness History: Motor deficits (none) Fever, weight loss, or other systemic symptoms (none) Bladder or bowel incontinence Past history of back pain Personal history of peripheral vascular disease Smoking history (quantity in pack-years) Dyslipidemia Personal history of malignancy Effect on daily activities Physical Exam Inspection: Comment on shape of spine – kyphosis, scoliosis, as well as posture Comment on any asymmetry of the back, including swelling, scars, or bruising Range of Motion/Gait Observe all active ranges of motion for the back Assess patient’s gait Physical Exam Palpation Palpate along spinous processes and paraspinal muscles of the back for tenderness Performs straight leg raise on both sides, with and without ankle dorsiflexion (negative) Testing on unaffected side is termed crossed straight leg raise, or well leg raise Palpate peripheral pulses (present) Abdominal exam should be performed to rule out an abdominal aortic aneurysm or visceral etiology Physical Exam Neurological exam Tests foot sensation (L4, L5, S1) Tests for saddle anesthesia (S3, S4, S5) Tests knee (L4) and ankle reflex (S1) Tests Babinski response Tests power of big toe and foot dorsiflexion (L5), as well as foot plantarflexion (S1) Assesses for hip abduction (L5) Hamstring reflex (L5)  Mechanical Low Back Pain Red Flags Lumbar Strain Osteoporosis: Degenerative Disease History of steroid use, Discs (spondylosis) chemotherapy and/or Facet Joints (osteoarthritis) radiation Spondylolisthesis Herniated disc Fractures: History of physical trauma Spinal stenosis Minor trauma in elderly or Osteoporosis with osteoporosis risk Fractures (consider acute vertebral fractures) Congenital Disease Sever kyphosis Severe scoliosis Cauda Equina Syndrome: Possible type II or type IV Diffuse motor/sensory loss transitional vertebrae Progressive & worsening Possible spondylosis neurological deficits Possible facet joint asymmetry Cauda Equina Syndrome  Nonmechanical Spine Disease Lumbar Strain Red Flags Neoplasia Multiple Myeloma Metastatic cancer (prostate) Neoplasia: Lymphoma and leukemia History of cancer Spinal cord tumors Age >50 Retroperitoneal tumors Unexplained weight loss Night pain or supine pain Infection: Severe fatigue Osteomyelitis Unexplained fever (>38°C) Septic discitis Night Sweats Paraspinous abscess Epidural abscess Inflammatory arthritis (often Infection: HLA-B27- associated) Fever, chills, weight loss Ankylosing spondylitis IV drug use Psoriatic spondylitis Immunocompromised Reactive arthritis (including steroids) Inflammatory bowel disease Scheuermann disease (osteochondrosis) Paget Disease Red Flags Visceral Disease General Vascular: History of significant vascular risk Pelvic Organs factors, clotting disorders, and Prostatitis cardiovascular disease Endometriosis Hemodynamic instability Chronic PID Unilateral limb symptoms Renal Disease including swelling and absence of Nephrolithiasis pulses, coldness Pyelonephritis Perinephric abscess Aortic aneurysm Gastrointestinal disease Aortic Aneurysm: Pancreatitis Abdominal pain (tearing) that Cholecystitis refers to the low back is Penetrating ulcer suggestive. Fat herniation of lumbar space FYI for now Red Flags: LRs Spinal Fracture: Prolonged corticosteroid use LR+: 48.5, LR-: 0.8 3 positive findings on the Henschke index: 1. Female 2. Age >70 years 3. Severe trauma 4. Prolonged use of corticosteroids LR+: 906, LR-: 0.6 Spinal malignancy History of cancer LR+: 35.0, LR-: 0.1 (Deyo and Diehl, 1988) LR+: 15.3, LR-: 0.7 (Reinus et al, 1998) More information at Downie et al (2013)  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 NEUROLOGICAL nerve root) Current or recent cancer history (other than Emergency MRI* and nonmelanoma skin caner) particularly NO YES specialist consultation breast, prostate, lung, thyroid, kidney and multiple myeolma NO YES Discuss choice of imaging study with patient’s oncologist Moderate to high risk for cancer (multiple risk factors/symptoms, history of cancer, strong clinical suspicion Radiograph suggests Evaluate for YES Plain Radiography possible cancer Malignancy plus ESR (or CRP) Radiograph normal, MRI but ESR high (or CRP) NO Adapted Adaptedfrom fromUpToDate UpToDateAlgorithm: Algorithm:Acute AcuteLow LowBack BackPain: Pain:Considerations Considerationsfor forImaging 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 Emergency MRI* and nonmelanoma skin caner) particularly NO YES specialist consultation breast, prostate, lung, thyroid, kidney and multiple myeolma MALIGNANCY NO YES Discuss choice of imaging study with patient’s oncologist Moderate to high risk for cancer (multiple risk factors/symptoms, history of cancer, strong clinical suspicion Radiograph suggests Evaluate for YES Plain Radiography possible cancer Malignancy plus ESR (or CRP) Radiograph normal, MRI but ESR high (or CRP) NO Adapted from UpToDate Algorithm: Acute Low Back Pain: Considerations for Imaging  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 INFECTION Level of suspicion for High MRI YES spinal infection Low ESR and/or CRP Elev. MRI NO Risk for vertebral compression fracture (advanced age, history of prolonged systemic steroids, significant trauma, mild trauma with history of risk factors for osteoporosis Plain Radiography NO YES Other patients (low back pain without other worrisome features and low risk for cancer, spinal Conservative therapy for 4-6 week. infection, or progressive neurologic impairment If no improvement in symptoms after 4-6 weeks, assess for subacute low back pain Adapted Adaptedfrom fromUpToDate UpToDateAlgorithm: Algorithm:Acute AcuteLow LowBack BackPain: Pain:Considerations Considerationsfor forImaging Imaging Labs: Complete Blood Count With Differential Actually composed of several different tests all categorized under the same umbrella RBC count Red blood cell distribution width (RDW) Hematocrit Hemoglobin Mean corpuscular volume (MCV) Mean corpuscular hemoglobin (MCHC) Platelets WBC count & differential Labs: Complete Blood Count With Differential Test Definition Relevant to LBP DDX Red Blood Cell (RBC) The number of RBCs per volume of N/A Count blood Amount of oxygen-carrying protein in Hemoglobin (Hb) N/A the blood Percentage of a given volume of Hematocrit (Hct) whole blood occupied by packed N/A RBCs Mean Corpuscular Amount of oxygen-carrying Hb inside N/A Volume RBCs Concentration Average concentration of Hb inside N/A (MCHC) RBCs RBC Distribution Measurement Variance in RBC size N/A Width (RDW) White Blood Cell The number of WBCs per volume of Applicable (WBC) Count blood Labs: Complete Blood Count With Differential Test Definition Relevant to LBP DDX WBC Differential Neutrophils* Neutrophilia Lymphocytes* Leukocytosis Monocytes N/A Eosinophils N/A Basophils N/A Platelet Count The number of platelets per N/A volume of blood Mean Platelet Measurement of platelet size N/A Volume (MPV) Reticulocytes Immature RBCs that contain no N/A nucleus but have residual RNA ** Most likely to be elevated in infection and cancers Labs: C-Reactive Protein (CRP) Acute phase protein which rises in response to inflammation Non-specific, but can be used together with signs and symptoms and other tests to evaluate for acute or chronic inflammation Acute Any infection, especially bacterial Acute flares or onset of inflammatory/immune-mediated disease Chronic Chronic infections Chronic inflammatory/immune-mediated conditions Labs: Erythrocyte Sedimentation Rate Measurement of the rate at which RBCs settle in saline solution or plasma over a specified time period Because inflammatory, neoplastic, infectious and necrotic diseases increase the protein content of plasma, RBCs tend to stack upon one another, increasing their weight, causing them to descend faster Non specific test used to help detect acute and chronic inflammation Does not change as rapidly as CRP Labs: Erythrocyte Sedimentation Rate (ESR) If elevated usually a result of globulins or fibrinogens Polymyalgia rheumatica Moderately elevated Inflammation, anemia, infection, pregnancy Very high Severe infection  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 Level of suspicion for High MRI YES spinal infection Low ESR and/or CRP Elev. MRI NO Risk for vertebral compression fracture (advanced age, history of prolonged systemic steroids, significant trauma, mild trauma with history of risk factors for osteoporosis FRACTURE Plain Radiography NO YES Other patients (low back pain without other worrisome features and low risk for cancer, spinal Conservative therapy for 4-6 week. infection, or progressive neurologic impairment If no improvement in symptoms after 4-6 weeks, assess for subacute low back pain Adapted from UpToDate Algorithm: Acute Low Back Pain: Considerations for Imaging  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 Level of suspicion for High MRI YES spinal infection Low ESR and/or CRP Elev. MRI NO Risk for vertebral compression fracture (advanced age,with no identifiable cause is NSLBP. >6 weeks history of prolonged systemic steroids, significant trauma,red flags must be ruled out in the However, mild trauma with history of risk factors for osteoporosis acute presentation and if there is no progress with conservative management Plain Radiography NO YES Other patients (low back pain without other worrisome features and low risk for cancer, spinal Conservative therapy for 4-6 week. infection, or progressive neurologic impairment If no improvement in symptoms after 4-6 weeks, assess for subacute low back pain Adapted from UpToDate Algorithm: Acute Low Back Pain: Considerations for Imaging X-Ray Imaging Form a short wavelength electromagnetic energy Photons traverse matter, they can be absorbed (a process known as “attenuation”) and/or scattered The density of a structure determines its ability to attenuate or “weaken” the x-ray beam air < fat < water < bone < metal Structures that have high attenuation (e.g. bone) appear white on the resulting images X-Ray Imaging – Plain Films X-rays pass through the patient and interact with a detection device (film) to produce a 2-dimensional projection image Structures closer to the film appear sharper and less magnified Contraindications: pregnancy (relative) Advantages: inexpensive, non-invasive, readily available, portable, reproducible, fast, easily read Disadvantages: radiation exposure (minimal), generally poor at distinguishing soft tissues X-Ray Imaging – Computed Tomography X-ray beam opposite a detector moves in a continuous 360º arc as patient is advanced through the scanner Anatomical structures are then reconstructed Attenuation is quantified in Hounsfield units: Windowing and leveling: adjusting the “window width” (range of Hounsfield units displayed) and “window level” (midpoint value of the window width) to maximally visualize certain anatomical structures (e.g. CT chest can be viewed using “lung”, “soft tissue”, and “bone” settings) X-Ray Imaging – Computed Tomography Advantages: Delineates soft tissues, excellent at delineating bones and identifying lung/liver masses May be used to guide biopsies Spiral/helical multidetector CT has fast data acquisition and allows 3D reconstruction CTA non-invasive compared to conventional angiography for visualization of vasculature Disadvantages: High radiation exposure Soft tissue characterization is inferior to that seen on MRI Requirement for contrast in some studies (e.g. IV, oral, rectal), Patient anxiety going through scanner Increased cost and decreased availability compared to plain film Requirement for expert interpretation of images MRI Imaging technique that does not use ionizing radiation and can produce images in virtually any plane Patient is placed in a magnetic field generated by electric current; protons, typically from water Molecules, align themselves along the plane of magnetization due to their intrinsic polarity. A pulsed radiofrequency beam is subsequently turned on and deflects all the protons off their aligned axes. When the radiofrequency beam is turned off, the protons return to their pre-excitation axis, giving off the energy they absorbed. This energy is measured with a detector and interpreted by software to generate MR images MRI MR image reflects signal intensity picked up by receiver. Signal intensity is dependent on: (1) Hydrogen density: tissues with low hydrogen density (e.g. cortical bone, lung) generate little to no MR signal compared to tissues with high hydrogen density (e.g. water) (2) Magnetic relaxation times (T1 and T2): reflect quantitative alterations in MR signal strength due to intrinsic properties of the tissue and its surrounding chemical and physical environment  MRI Imaging Contrast Main Advantages Techniques Enhancements Application Contrast dependent on Sensitive for detection of acute the molecular motion ischemic stroke and differentiating of water Diffusion- an acute stroke from other Decreased diffusion is Weighted Neuroradiology neurologic pathologies hyperintense (bright), Imaging Acute infarction and abscess whereas increased collections appear hyperintense diffusion is hypointense due to restricted diffusion (dark) Fluid is hypointense Often considered an anatomic scan T1- Body soft (dark) and fat is since they provide a reference for Weighted tissues hyperintense (bright) functional imaging Fluid is hyperintense Often considered a pathologic scan T2- (bright) and fat is Body soft since they will highlight edematous Weighted hypointense (dark) tissues areas associated with certain *WW2 pathologies DEXA – Bone Mineral Density Gold standard for measuring bone mineral density T-score: the number of standard deviations from the young adult mean, most clinically valuable osteopenia: –2.5< T-score 30 = relevant level of catastrophizing Outcomes Factors with consistent evidence of no association with poor outcomes at long term in acute– subacute LBP Lower level of education was not associated with worse work-related outcomes, being in line with the evidence provided by previous reviews in LBP and musculoskeletal populations Outcomes Factors with inconsistent evidence of association with poor outcomes at long term in acute– subacute LBP Female gender Positive sciatic or nerve root involvement initially Having an episode of prior back pain Fear avoidance beliefs Fear and avoidance are context dependent You can prioritize the goal of avoiding pain without reporting fear and you can prioritize the threat whilst self-reporting fear. Measurement scales? Fear Avoidance Beliefs https://doi.org/10.1016/j.cobeha.2018.12.007 FABQ - Fear Avoidance Beliefs Questionnaire The FABQ measures patient's fear of pain and consequent avoidance of physical activity (PA) because of their fear. Intended Population: The FABQ has been proven to be a reliable and valid assessment tool based on patients with chronic low back pain. In recent research, the FABQ is being used in populations with acute low back pain to identify the risk of long-term disability. It is also used in patients with spinal injuries, musculoskeletal conditions and chronic pain 16 items on a 7 point Likert Scale from 0-6 FABQ - Fear Avoidance Beliefs Questionnaire Item scores are summed into total score and two subscale scores: A 4 item physical activity scale (FABQ-PA) An 7 item work subscale (FABQ-W) Minimum total score=0, maximum total score =96 Subscale score ranges: FABQ-PA:0-24; FABQ-W: 0-42 Interpreting the results: FABQ-W score > 34 is significant FABQ-PA >15 is significant Outcomes Other factors with insufficient evidence of association with LBP outcomes at long term Low work social support Low social activity Age Key Clinical Points Nonspecific low back pain is diagnosed on the basis of the exclusion of specific causes, usually by means of history taking and physical examination. Rule out red flags and consider yellow flags Imaging is not routinely indicated in patients with nonspecific low back pain. Most patients with an acute episode of nonspecific low back pain will recover in a short period of time. Consistent re-evaluation of progress is important. Address early if progress is delayed. Document well - improvements/changes in symptoms and function, and patient assessment of effects of individual modalities. This can be done with the use of physical exam and questionnaires Key Messages to Convey to the Patient In the absence of red flags, reassure the patient there is no reason to suspect a serious cause Reinforce that pain typically resolves in a few weeks without intervention Encourage patient to keep active and recommend physical activity to prevent recurrence Encourage and support pain self-management When to Consider Problems Beyond the Spine Systemically unwell Nonmechanical pain (i.e., pain that is unrelated to movement) Hip joint signs (consider hip joint disease) Abdominal pulsations (consider abdominal aortic aneurysm) Gynecologic, renal/urinary tract, gastrointestinal signs and symptoms (e.g., abdominal tenderness, hematuria) (consider visceral origin) Atherosclerotic risk factors, claudication (consider vascular origin)