# Seminar 08: Musculoskeletal Conditions ## Year 3: Family Medicine Clerkship --- ## Learning Objectives By the end of this seminar, students will be able to: 1. Evaluate common joint complaints in primary care 2. Diagnose and manage osteoarthritis 3. Recognize inflammatory arthritis presentations 4. Assess and treat common soft tissue conditions 5. Apply appropriate imaging and testing strategies 6. Identify red flags requiring urgent evaluation --- ## Seminar Outline ### I. Approach to Joint Pain History taking for joint complaints follows a systematic approach that distinguishes mechanical from inflammatory causes and identifies patterns suggesting specific diagnoses. Location assessment determines whether the problem involves one joint (monoarticular), few joints (oligoarticular, two to four), or many joints (polyarticular), with each pattern suggesting different etiologies. Duration clarifies whether the process is acute (less than six weeks) or chronic, guiding urgency and differential diagnosis. Pattern recognition notes whether involvement is symmetric or asymmetric, which helps distinguish conditions like rheumatoid arthritis (typically symmetric) from gout or psoriatic arthritis (often asymmetric). Character of symptoms and their relationship to activity helps categorize mechanical versus inflammatory processes. Distinguishing mechanical from inflammatory joint pain represents a fundamental diagnostic step. Mechanical pain typically worsens with activity and improves with rest, as movement stresses damaged structures. Morning stiffness in mechanical conditions lasts less than thirty minutes, often described as a "gelling" phenomenon that quickly resolves with movement. In contrast, inflammatory pain paradoxically improves with activity and may worsen with prolonged rest. Morning stiffness in inflammatory conditions persists longer than one hour and requires sustained activity to resolve. Swelling is typically more prominent in inflammatory conditions, and systemic symptoms such as fever, fatigue, and weight loss suggest inflammatory or infectious etiologies. Physical examination begins with inspection for visible swelling, erythema, deformity, and muscle wasting around affected joints. Palpation assesses warmth indicating inflammation, presence of effusion (fluctuance suggesting fluid accumulation), point tenderness localizing pathology, and crepitus suggesting cartilage damage or tendon pathology. Range of motion evaluation compares active motion (patient-generated) to passive motion (examiner-generated); pain with both suggests intra-articular pathology, while pain primarily with active motion may indicate periarticular soft tissue problems. Stability testing evaluates ligament integrity through stress maneuvers. Functional assessment observes gait, grip strength, and ability to perform specific tasks relevant to the affected joint. Distribution patterns provide diagnostic clues that narrow the differential. Monoarticular presentations suggest gout, septic arthritis, trauma, or localized osteoarthritis. Oligoarticular involvement (two to four joints) raises consideration of reactive arthritis, psoriatic arthritis, or gout affecting multiple joints. Polyarticular presentations suggest rheumatoid arthritis, osteoarthritis (particularly hands and knees), viral arthritis, or systemic lupus erythematosus. Symmetric involvement of small joints, particularly metacarpophalangeal and proximal interphalangeal joints with wrist involvement, characterizes rheumatoid arthritis. Distal interphalangeal involvement suggests osteoarthritis or psoriatic arthritis. Asymmetric large joint involvement raises consideration of spondyloarthropathies. Panel A: Joint pain history framework with questions organized by location, duration, pattern, and character. Panel B: Mechanical versus inflammatory pain comparison showing morning stiffness duration, activity effects, and swelling characteristics. Panel C: Physical examination sequence for joint assessment with specific findings to document. Panel D: Distribution pattern diagnostic implications showing monoarticular, oligoarticular, and polyarticular differentials. --- ### II. Osteoarthritis Osteoarthritis represents the most common form of arthritis, affecting over thirty million American adults with prevalence increasing with age. This degenerative condition involves progressive loss of articular cartilage, subchondral bone changes including sclerosis and cyst formation, osteophyte development at joint margins, and mild synovial inflammation. Risk factors include advancing age as the primary determinant, obesity particularly for knee osteoarthritis, prior joint injury accelerating degeneration, genetic predisposition, repetitive occupational stress, and female sex with increased risk following menopause. The joints most commonly affected include the hands (distal interphalangeal, proximal interphalangeal, and first carpometacarpal joints), knees, hips, and spine. Clinical presentation follows characteristic mechanical patterns that typically allow diagnosis without extensive testing. Pain develops gradually over months to years and is described as aching, worsening with activity and improving with rest. Morning stiffness lasts less than thirty minutes and resolves quickly with movement, distinguishing osteoarthritis from inflammatory conditions. Physical examination reveals bony enlargement at affected joints from osteophyte formation, crepitus with joint movement reflecting cartilage damage, limited range of motion, and joint line tenderness. Heberden nodes at the distal interphalangeal joints and Bouchard nodes at the proximal interphalangeal joints represent characteristic findings in hand osteoarthritis. Effusions may occur, particularly in the knee, but are typically non-inflammatory. Notably, osteoarthritis spares the metacarpophalangeal joints, wrists, and ankles unless secondary to prior injury. Diagnosis is primarily clinical based on characteristic history and examination findings. Radiographic hallmarks when imaging is performed include joint space narrowing reflecting cartilage loss, osteophytes at joint margins, subchondral sclerosis (increased bone density), and subchondral cysts. Standing weight-bearing radiographs provide optimal assessment for knee osteoarthritis. Importantly, correlation between radiographic severity and symptoms is imperfect; some patients experience significant pain despite mild imaging changes, while others have advanced radiographic changes with minimal symptoms. Laboratory testing is not required for diagnosis but may help exclude inflammatory arthritis when features are atypical; in osteoarthritis, inflammatory markers and rheumatoid factor are typically normal. Joint aspiration when performed reveals non-inflammatory synovial fluid with white blood cell count below 2000 per microliter. Differential diagnosis includes conditions with overlapping presentations requiring distinction. Rheumatoid arthritis affects small joints symmetrically but spares distal interphalangeal joints, causes prolonged morning stiffness exceeding one hour, and demonstrates positive rheumatoid factor and anti-CCP antibodies in most cases. Gout causes acute monoarticular inflammation with characteristic crystal findings on synovial fluid analysis. Pseudogout (calcium pyrophosphate deposition disease) produces acute inflammation often affecting knees or wrists, with different crystal morphology on polarized microscopy. Psoriatic arthritis may involve distal interphalangeal joints similarly to osteoarthritis but features associated psoriatic skin changes and nail pitting. Septic arthritis presents as acute monoarticular inflammation with fever and markedly inflammatory synovial fluid requiring emergent treatment. Panel A: Osteoarthritis risk factors illustrated with commonly affected joints marked on body diagram. Panel B: Clinical features comparison distinguishing osteoarthritis from inflammatory arthritis by morning stiffness, activity effects, and examination findings. Panel C: Radiographic findings in osteoarthritis with annotated images showing joint space narrowing, osteophytes, and subchondral changes. Panel D: Differential diagnosis grid comparing osteoarthritis with gout, rheumatoid arthritis, psoriatic arthritis, and septic arthritis. --- ### III. Osteoarthritis Management Non-pharmacological treatments form the foundation of osteoarthritis management and should be implemented before or alongside medications. Weight loss demonstrates consistent benefit for knee and hip osteoarthritis, with meaningful pain and function improvement occurring with as little as five percent body weight reduction; the biomechanical impact is substantial, as each pound of body weight translates to approximately four pounds of force across the knee with walking. Exercise programs including aerobic conditioning, strengthening of periarticular muscles, and flexibility training reduce pain and improve function across osteoarthritis locations. Physical therapy provides individualized exercise prescription and may incorporate modalities such as heat, ultrasound, and manual therapy techniques. Assistive devices including canes (used in the contralateral hand for hip or knee arthritis), braces, and orthotics reduce joint loading and improve stability. Occupational therapy addresses adaptive equipment and joint protection strategies for hand osteoarthritis affecting daily function. Topical therapies offer localized treatment with reduced systemic exposure, making them attractive options especially for superficial joints. Topical nonsteroidal anti-inflammatory drugs (NSAIDs) including diclofenac gel and solution demonstrate efficacy comparable to oral NSAIDs for knee and hand osteoarthritis while causing fewer gastrointestinal and cardiovascular side effects. American College of Rheumatology guidelines recommend topical NSAIDs over oral NSAIDs for patients 75 years and older with knee osteoarthritis given the safer systemic profile. Topical capsaicin depletes substance P from peripheral nerve endings, providing analgesia after regular application for several weeks; the initial burning sensation often limits tolerance but typically diminishes with continued use. Topical treatments work best for accessible superficial joints including knees, hands, and ankles; deeper joints like hips are unlikely to benefit from topical approaches. Oral pharmacotherapy adds to non-pharmacological measures when additional pain relief is needed. Acetaminophen at doses up to 3000 mg daily provides modest benefit with an excellent safety profile, making it appropriate for patients who cannot take NSAIDs, though recent evidence suggests limited efficacy specifically for osteoarthritis. Oral NSAIDs offer superior pain relief but carry gastrointestinal, cardiovascular, and renal risks requiring careful patient selection, lowest effective dose, and limited duration when possible. Proton pump inhibitors should accompany NSAID use in patients at elevated gastrointestinal risk. Duloxetine, a serotonin-norepinephrine reuptake inhibitor antidepressant, has FDA approval for chronic musculoskeletal pain including osteoarthritis and may particularly benefit patients with central sensitization or comorbid depression. Glucosamine and chondroitin supplements are widely used but lack convincing evidence of clinical efficacy in rigorous trials. Advanced therapies serve patients with refractory symptoms despite conservative measures. Intra-articular corticosteroid injection provides short-term pain relief typically lasting six to twelve weeks for knee osteoarthritis; recent evidence raises concerns that repeated injections may accelerate cartilage loss, suggesting judicious use with intervals of at least three to four months between injections. Hyaluronic acid injections (viscosupplementation) have variable evidence but may benefit some knee osteoarthritis patients, particularly those with contraindications to other treatments; effects are modest and delayed, typically requiring several weeks to manifest. Total joint arthroplasty represents definitive treatment for end-stage osteoarthritis of hips and knees unresponsive to conservative management, providing excellent pain relief and functional improvement in appropriately selected patients. Orthopedic surgery referral is appropriate when quality of life is significantly impaired despite optimal non-surgical management. Panel A: Non-pharmacological treatment pyramid showing exercise, weight loss, physical therapy, and assistive devices with evidence levels for each. Panel B: Topical treatment options with mechanisms, application instructions, and appropriate joint locations. Panel C: Oral medication comparison showing efficacy, safety profile, and patient selection considerations for acetaminophen, NSAIDs, and duloxetine. Panel D: Advanced therapy decision tree for corticosteroid injection, hyaluronic acid, and surgical referral timing. --- ### IV. Gout Gout results from monosodium urate crystal deposition in joints following sustained hyperuricemia, representing the most common inflammatory arthritis in men. Risk factors include male sex (with gout uncommon in premenopausal women), older age, obesity, dietary factors (red meat, seafood, and alcohol especially beer), medications that raise uric acid (thiazide diuretics, low-dose aspirin), chronic kidney disease impairing uric acid excretion, and genetics affecting uric acid metabolism. The disease progresses through asymptomatic hyperuricemia, acute gouty arthritis with intermittent attacks, and potentially to chronic tophaceous gout with persistent joint damage and visible tophi deposits in advanced untreated disease. The classic presentation of acute gout involves sudden onset of severe monoarticular inflammation, often beginning at night or early morning. The first metatarsophalangeal joint (podagra) is most commonly affected, involved in approximately fifty percent of initial attacks and eventually in nearly all gout patients. Other commonly affected joints include the ankle, knee, wrist, and olecranon bursa. The affected joint becomes exquisitely tender, erythematous, warm, and swollen, with pain often described as the worst the patient has experienced. Attacks are self-limited, typically resolving over days to two weeks even without treatment. Triggers for acute attacks include dietary indiscretion, alcohol intake, dehydration, acute illness, surgery, and initiation or changes in urate-lowering therapy. Diagnosis can be established clinically in classic presentations but is definitively confirmed by demonstrating negatively birefringent needle-shaped monosodium urate crystals in synovial fluid under polarized microscopy. Serum uric acid is often elevated but may be normal or even low during acute attacks due to inflammatory cytokine effects; therefore, normal uric acid does not exclude gout. Joint aspiration should be performed whenever septic arthritis is in the differential diagnosis, as the clinical presentations can overlap. Dual-energy CT and musculoskeletal ultrasound (demonstrating the "double contour" sign over cartilage) provide non-invasive diagnostic options when joint aspiration is not feasible. Radiographic changes including punched-out erosions with overhanging edges appear in advanced disease but are absent early. Acute gout treatment prioritizes rapid inflammation control using one of several effective options. NSAIDs at full anti-inflammatory doses (such as indomethacin 50 mg three times daily or naproxen 500 mg twice daily) provide first-line treatment when not contraindicated by renal, cardiovascular, or gastrointestinal conditions. Colchicine is effective when initiated within 36 hours of attack onset; the modern low-dose regimen of 1.2 mg followed by 0.6 mg one hour later produces fewer gastrointestinal side effects than older high-dose protocols while maintaining efficacy. Corticosteroids, either oral (prednisone 30-40 mg daily for five days), intramuscular, or intra-articular, offer excellent efficacy for patients who cannot tolerate NSAIDs or colchicine. Urate-lowering therapy should not be initiated during acute attacks, as fluctuations in uric acid may prolong or worsen flares; however, patients already on established urate-lowering therapy should continue it during attacks. Panel A: Gout pathophysiology showing progression from hyperuricemia through crystal deposition to acute inflammation and chronic disease. Panel B: Acute gout clinical presentation with characteristic joint involvement locations and examination findings. Panel C: Diagnostic approach including synovial fluid analysis with crystal morphology under polarized light. Panel D: Acute treatment algorithm showing NSAIDs, colchicine, and corticosteroid options with patient selection considerations. --- ### V. Urate-Lowering Therapy and Inflammatory Arthritis Urate-lowering therapy (ULT) is indicated for patients with frequent gout attacks (two or more per year), presence of tophi, urate nephropathy, or uric acid kidney stones. The target serum uric acid is below 6 mg/dL, which promotes dissolution of tissue urate deposits; some guidelines recommend targeting below 5 mg/dL for patients with tophi to accelerate resolution. Allopurinol, a xanthine oxidase inhibitor, represents first-line therapy, started at 100 mg daily (lower in renal impairment) and titrated by 100 mg increments every two to four weeks until target uric acid is achieved, which may require doses of 300 mg or higher. Febuxostat, an alternative xanthine oxidase inhibitor, is appropriate for patients who cannot tolerate allopurinol or fail to achieve target despite adequate dosing; an FDA cardiovascular warning limits its use to patients who have failed allopurinol. Probenecid, a uricosuric agent promoting renal uric acid excretion, is less commonly used but may be appropriate in selected patients with adequate renal function. Prophylactic anti-inflammatory therapy with low-dose colchicine (0.6 mg once or twice daily) or NSAID during the first three to six months of ULT initiation prevents mobilization flares triggered by fluctuating uric acid levels. Rheumatoid arthritis requires early recognition and rheumatology referral to prevent irreversible joint damage through timely disease-modifying therapy. The typical presentation involves symmetric polyarthritis affecting small joints of the hands and feet, particularly metacarpophalangeal, proximal interphalangeal, and wrist joints, while characteristically sparing distal interphalangeal joints. Morning stiffness lasting longer than one hour represents a hallmark feature distinguishing rheumatoid from osteoarthritis. Systemic symptoms including fatigue, low-grade fever, and weight loss may accompany joint symptoms. Laboratory findings include elevated inflammatory markers (ESR and CRP), positive rheumatoid factor in approximately seventy percent of cases, and anti-cyclic citrullinated peptide (anti-CCP) antibodies, which are more specific than rheumatoid factor. Extra-articular manifestations include rheumatoid nodules, pulmonary disease, and ocular inflammation. Psoriatic arthritis affects up to thirty percent of patients with psoriasis, though arthritis may precede skin findings in some cases. The presentation is heterogeneous, including asymmetric oligoarthritis, symmetric polyarthritis resembling rheumatoid arthritis, distal interphalangeal predominant disease, spondylitis, and arthritis mutilans causing severe destructive disease. Distinctive features include dactylitis ("sausage digits" from inflammation of entire fingers or toes), enthesitis (inflammation at tendon-bone insertions), and distal interphalangeal joint involvement. Associated findings include psoriatic skin plaques, nail changes (pitting, onycholysis), and sacroiliitis. Laboratory studies are typically negative for rheumatoid factor; HLA-B27 may be positive, particularly in patients with spinal involvement. Septic arthritis constitutes a medical emergency requiring urgent diagnosis and treatment to prevent joint destruction. The typical presentation involves acute monoarticular inflammation with a hot, swollen, extremely painful joint and fever. Risk factors include pre-existing joint disease, immunocompromise, intravenous drug use, recent joint procedures, and skin infections. Staphylococcus aureus is the most common causative organism. Any joint suspected of septic arthritis requires immediate aspiration for cell count, Gram stain, and culture; synovial white blood cell count typically exceeds 50,000 per microliter and is often much higher. Treatment requires prompt intravenous antibiotics and orthopedic consultation for consideration of joint drainage. A critical principle is never to inject corticosteroids into a joint that might be septic, as this can convert a potentially treatable infection into devastating joint destruction. Panel A: Urate-lowering therapy protocol showing allopurinol initiation, titration, target uric acid, and prophylaxis coverage. Panel B: Rheumatoid arthritis recognition features including joint distribution, laboratory findings, and referral urgency. Panel C: Psoriatic arthritis patterns with dactylitis, enthesitis, and skin/nail associations illustrated. Panel D: Septic arthritis emergency algorithm emphasizing aspiration, antibiotics, and surgical consultation timing. --- ### VI. Shoulder Conditions Rotator cuff pathology represents the most common cause of shoulder pain presenting to primary care. The rotator cuff comprises four muscles (supraspinatus, infraspinatus, subscapularis, and teres minor) whose tendons converge to stabilize the humeral head in the glenoid and enable coordinated shoulder movement. Symptoms include anterolateral shoulder pain often radiating to the lateral deltoid region, night pain disrupting sleep, and difficulty with overhead activities and reaching behind the back. Impingement occurs when rotator cuff tendons are compressed between the humeral head and the coracoacromial arch during arm elevation. The spectrum of pathology ranges from tendinopathy without structural damage through partial tears to complete tears causing weakness. Risk increases with age, overhead activities, and repetitive use. Physical examination systematically evaluates rotator cuff integrity through specific maneuvers. A painful arc of motion, with pain occurring between 60 and 120 degrees of abduction that diminishes above and below this range, suggests impingement. The Neer impingement test involves passive forward flexion with the arm internally rotated while stabilizing the scapula; pain reproduction suggests impingement. The Hawkins test flexes the elbow to 90 degrees and internally rotates the arm; pain indicates impingement. Strength testing evaluates specific rotator cuff muscles: the empty can test (resisted abduction with arm in scaption and thumb pointing down) assesses supraspinatus; external rotation against resistance tests infraspinatus; the lift-off test or belly press evaluates subscapularis. Weakness with strength testing suggests a rotator cuff tear rather than tendinopathy alone. Adhesive capsulitis (frozen shoulder) produces progressive shoulder stiffness through capsular inflammation and fibrosis. This condition affects two to five percent of adults, with markedly increased prevalence in patients with diabetes (occurring in ten to twenty percent) and thyroid disease. The clinical course progresses through three overlapping phases: the painful or freezing phase (two to nine months) with increasing pain and progressive loss of motion; the frozen phase (four to twelve months) with maximal stiffness but gradually decreasing pain; and the thawing phase (five to twenty-four months) with slow return of motion. The diagnostic hallmark is restricted active and passive range of motion in all planes, particularly external rotation, distinguishing this from rotator cuff disease where passive motion is typically preserved. Most patients eventually recover, though the process may take one to three years. Imaging and treatment decisions follow the clinical evaluation. Plain radiographs constitute appropriate initial imaging to exclude fracture, arthritis, and calcific tendinopathy. MRI provides definitive soft tissue evaluation when rotator cuff tear is suspected clinically (particularly with weakness) or when symptoms persist despite conservative treatment. Treatment for most shoulder conditions begins conservatively with activity modification avoiding aggravating movements, NSAIDs for pain and inflammation, and physical therapy emphasizing rotator cuff strengthening, scapular stabilization, and range of motion. Subacromial corticosteroid injection provides substantial short-term relief for impingement and rotator cuff tendinopathy. Surgical referral is appropriate for complete rotator cuff tears in active patients, particularly acute tears or those with significant weakness, and for other conditions failing adequate conservative management. Panel A: Rotator cuff anatomy showing the four muscles, their origins, insertions, and functions in shoulder movement. Panel B: Shoulder examination maneuvers including Neer, Hawkins, empty can, and external rotation testing with positive findings indicated. Panel C: Adhesive capsulitis phases timeline showing symptom evolution and treatment approach at each stage. Panel D: Shoulder imaging and treatment algorithm based on clinical findings and treatment response. --- ### VII. Knee and Hip Conditions Knee osteoarthritis produces mechanical joint symptoms with predilection for the medial compartment reflecting weight-bearing patterns, though lateral and patellofemoral compartments may also be affected. Physical examination identifies joint line tenderness (medial more commonly than lateral), bony enlargement from osteophyte formation, crepitus with knee flexion and extension, possible effusion detected by ballottement or bulge sign, and often varus (bow-leg) deformity in advanced medial disease. Standing anteroposterior radiographs are essential, as supine imaging may underestimate joint space narrowing; lateral views assess patellofemoral involvement. Management follows osteoarthritis principles with emphasis on quadriceps strengthening to stabilize the joint, weight management for overweight patients, and consideration of unloader braces designed to shift weight-bearing forces from the affected to the unaffected compartment. Meniscal tears result from acute injury in younger patients (typically twisting injuries with the foot planted) or degenerative changes in older adults where tears may occur without distinct injury or be incidentally discovered on imaging. The medial meniscus is more commonly affected. Symptoms include pain at the joint line, mechanical symptoms such as catching, locking, or giving way, and swelling. Examination reveals joint line tenderness, possible effusion, and may demonstrate a positive McMurray test (pain or palpable click with combined knee flexion, tibial rotation, and extension). MRI confirms the diagnosis when clinical uncertainty exists or surgical consideration is warranted. Importantly, degenerative meniscal tears in older adults often coexist with osteoarthritis and frequently respond to the same conservative treatments; arthroscopic partial meniscectomy provides no benefit over physical therapy for most degenerative tears and should be reserved for persistent mechanical symptoms failing conservative management. Ligamentous knee injuries span from minor sprains to complete tears requiring surgical reconstruction. Anterior cruciate ligament (ACL) injuries typically occur with pivoting, deceleration, or landing from jumps, often producing an audible pop and immediate swelling (hemarthrosis). Examination demonstrates increased anterior tibial translation relative to the femur on Lachman test (more sensitive) and anterior drawer test. Medial collateral ligament (MCL) injuries result from valgus stress and cause medial knee pain with laxity on valgus stress testing. Most MCL tears heal with conservative management including bracing and physical therapy, while ACL tears in active patients typically require surgical reconstruction to restore stability and enable return to cutting and pivoting activities. Hip pathology presents with groin pain that may radiate to the anterior thigh or even to the knee, potentially causing diagnostic confusion. Hip osteoarthritis produces mechanical groin pain with restricted range of motion, particularly internal rotation (often the first motion limited) and flexion. The FABER test (flexion, abduction, external rotation positioning with downward pressure on the knee) reproduces posterior hip or sacroiliac pain. Greater trochanteric pain syndrome, previously termed trochanteric bursitis, causes lateral hip pain at the greater trochanter reproduced by palpation, with preserved range of motion distinguishing it from intra-articular hip disease. This condition results primarily from gluteal tendinopathy rather than isolated bursal inflammation. Treatment emphasizes activity modification, iliotibial band stretching, physical therapy for gluteal strengthening, and local corticosteroid injection for refractory cases. Panel A: Knee examination sequence including inspection, palpation for effusion, range of motion, and stability testing with specific maneuvers illustrated. Panel B: Meniscal tear presentation, McMurray test technique, and management approach distinguishing acute traumatic from degenerative tears. Panel C: Ligament injury mechanisms and examination findings for ACL and MCL with management implications. Panel D: Hip pain differentiation between intra-articular osteoarthritis, greater trochanteric pain syndrome, and referred pain sources. --- ### VIII. Low Back Pain Low back pain affects approximately eighty percent of adults at some point, making it among the most common reasons for primary care visits. Initial evaluation must distinguish mechanical causes, which comprise over ninety percent of cases, from serious underlying pathology requiring urgent intervention. The history characterizes pain location, radiation pattern, onset circumstances, duration, and aggravating and alleviating factors. Mechanical back pain typically worsens with activity and improves with rest. Radicular symptoms including pain radiating below the knee in a dermatomal distribution, numbness, tingling, and weakness suggest nerve root involvement requiring more detailed neurological assessment. Most acute low back pain episodes resolve within four to six weeks regardless of treatment, making reassurance and maintenance of normal activities the foundation of initial management. Red flag symptoms demand immediate attention and investigation for serious underlying conditions. Cauda equina syndrome presents with saddle anesthesia (numbness in the perineal region), urinary retention or incontinence, and bilateral leg weakness or numbness; this represents a surgical emergency requiring urgent MRI and neurosurgical evaluation. Cancer indicators include unexplained weight loss, history of malignancy, pain at rest or at night, and age over fifty with new-onset back pain. Infection markers encompass fever, intravenous drug use, recent bacterial infection, and immunocompromise. Vertebral compression fracture risk increases with osteoporosis, chronic corticosteroid use, older age, and trauma even if seemingly minor. Rapidly progressive neurological deficits warrant emergent evaluation regardless of other features. Physical examination evaluates spinal mechanics, identifies neurological deficits, and screens for non-spinal causes of back pain. Inspection notes posture, spinal curvature, and gait. Palpation identifies point tenderness over vertebrae (suggesting possible fracture or infection) versus paraspinal muscle tenderness (consistent with muscular strain). Range of motion assessment notes pain provocation with specific movements. Neurological examination includes motor strength testing of key myotomes (hip flexion L2, knee extension L3-4, ankle dorsiflexion L4-5, ankle plantarflexion S1), sensory testing in dermatomal distributions, and deep tendon reflexes (patellar L4, Achilles S1). The straight leg raise test is positive when radicular leg pain is reproduced with hip flexion and knee extension at less than 60 degrees elevation, indicating nerve root tension consistent with disc herniation. Imaging requires judicious application guided by clinical findings rather than routine ordering. Imaging is not indicated for acute low back pain without red flags, as abnormalities are extremely common in asymptomatic individuals (disc bulges on MRI are present in a majority of adults over 40) and findings rarely change management. Plain radiographs are appropriate when fracture is suspected or for patients over fifty with new-onset pain suggesting possible malignancy. MRI is the modality of choice when serious pathology (infection, cancer, cauda equina syndrome) is suspected or for patients with radiculopathy being considered for interventional or surgical treatment. Treatment emphasizes maintaining activity as tolerated (bed rest is not recommended and delays recovery), NSAIDs as first-line analgesia, and avoidance of opioids for routine low back pain. Physical therapy with active exercise is beneficial for subacute and chronic pain. Panel A: Low back pain evaluation algorithm showing triage by red flags and neurological findings with urgency levels. Panel B: Red flag symptoms organized by condition (cauda equina, cancer, infection, fracture) with specific clinical features. Panel C: Neurological examination for low back pain showing myotome testing, dermatomal sensory assessment, and reflexes. Panel D: Imaging decision framework based on red flags, duration, and treatment response. --- ### IX. Soft Tissue Conditions Tendinopathies represent common causes of localized musculoskeletal pain resulting from overuse, microtrauma, and degenerative changes rather than acute inflammation. Current understanding recognizes that chronic tendon problems involve tendon degeneration (tendinosis) more than active inflammation (tendinitis), though the term tendinopathy encompasses both. Common locations include lateral epicondylosis (tennis elbow) causing lateral elbow pain reproduced by resisted wrist extension, medial epicondylosis (golfer's elbow) with medial elbow pain worsened by resisted wrist flexion, de Quervain tenosynovitis affecting the thumb abductor and extensor tendons at the radial wrist with positive Finkelstein test, and plantar fasciitis causing heel pain worst with first steps in the morning. Treatment emphasizes relative rest from aggravating activities, eccentric strengthening exercises which have specific evidence for tendinopathy, and gradual return to activity. Corticosteroid injections provide short-term relief but may impair tendon healing. Carpal tunnel syndrome results from median nerve compression within the carpal tunnel at the wrist, representing the most common peripheral neuropathy. Patients report numbness, tingling, and pain in the median nerve distribution (thumb, index, middle, and radial half of ring finger), often worse at night and with sustained wrist flexion activities. Examination may reveal positive Tinel sign (tingling with percussion over the carpal tunnel) and Phalen sign (symptoms reproduced by sustained wrist flexion for sixty seconds). Late findings include thenar atrophy and weakness of thumb opposition. Nerve conduction studies confirm the diagnosis and assess severity when clinical features are unclear or surgical treatment is contemplated. Treatment begins with nighttime wrist splinting in neutral position and ergonomic modifications. Corticosteroid injection provides temporary relief. Surgical carpal tunnel release is indicated for persistent symptoms despite conservative treatment, objective nerve dysfunction on testing, or thenar weakness/atrophy. Common sprain and strain injuries follow characteristic patterns. Ankle sprains most commonly involve the lateral ligament complex (anterior talofibular ligament) from inversion injuries. Ottawa ankle rules guide radiograph decisions, recommending imaging for inability to bear weight immediately and in the emergency department or bone tenderness at the posterior edge or tip of either malleolus or at the base of the fifth metatarsal or navicular. Management of grade I and II sprains emphasizes functional treatment with weight-bearing as tolerated, progressive mobilization, and ankle strengthening rather than prolonged immobilization. Muscle strains commonly affect the hamstrings, quadriceps, and gastrocnemius; treatment involves relative rest, ice for acute injury, progressive stretching and strengthening, and gradual return to activity. Injection therapy serves diagnostic and therapeutic purposes for various musculoskeletal conditions. Corticosteroid injection combined with local anesthetic provides both immediate diagnostic information (pain relief confirming the injection targeted the correct structure) and therapeutic benefit lasting weeks to months. Common injection sites include the subacromial space for rotator cuff pathology, the lateral epicondyle for tennis elbow, the first dorsal compartment for de Quervain tenosynovitis, the carpal tunnel for carpal tunnel syndrome, and intra-articular injection for knee or shoulder arthritis. Risks include post-injection flare, soft tissue atrophy with superficial injections, and tendon weakening with repeated injections. Contraindications include overlying skin infection and suspected joint infection (septic arthritis must be excluded before any joint injection). Panel A: Common tendinopathy locations with clinical features, provocative tests, and treatment approaches for each. Panel B: Carpal tunnel syndrome evaluation showing symptom distribution, examination maneuvers, and treatment progression from conservative to surgical. Panel C: Ankle sprain evaluation using Ottawa rules with treatment approach by severity grade. Panel D: Injection therapy common sites with indications, technique notes, and precautions. --- ### X. Osteoporosis and Red Flags Osteoporosis screening identifies patients at risk for fragility fractures before they occur. The US Preventive Services Task Force recommends bone mineral density testing by dual-energy X-ray absorptiometry (DXA) for all women aged 65 and older (Grade B recommendation) and for younger postmenopausal women with elevated fracture risk assessed by clinical tools. The FRAX calculator estimates ten-year probability of major osteoporotic fracture and hip fracture based on clinical risk factors (age, sex, prior fracture, parental hip fracture, smoking, glucocorticoid use, rheumatoid arthritis, secondary osteoporosis, alcohol use) with or without bone density results. DXA results are reported as T-scores comparing to young adult peak bone mass: T-score at or below minus 2.5 defines osteoporosis; between minus 1.0 and minus 2.5 indicates osteopenia; above minus 1.0 is normal. Treatment is generally recommended when T-score is at or below minus 2.5, when low-trauma fracture has occurred (regardless of T-score), or when FRAX-calculated ten-year risk exceeds three percent for hip fracture or twenty percent for major osteoporotic fracture. Pharmacological treatment reduces fracture risk in patients meeting treatment criteria. Bisphosphonates including alendronate, risedronate, and intravenous zoledronic acid inhibit osteoclast-mediated bone resorption and represent first-line therapy. Oral bisphosphonates require specific administration to maximize absorption and minimize esophageal irritation: taking on an empty stomach with a full glass of plain water, remaining upright for thirty minutes, and avoiding other oral intake. Denosumab, a RANK ligand inhibitor administered by subcutaneous injection every six months, offers an alternative for patients intolerant of or unsuitable for bisphosphonates. Calcium intake should total 1000 to 1200 mg daily (preferably from diet), and vitamin D supplementation (800 to 1000 IU daily) should maintain 25-hydroxyvitamin D levels above 30 ng/mL. Weight-bearing exercise and fall prevention strategies complement pharmacotherapy. Musculoskeletal red flags requiring urgent evaluation include several emergency conditions. Septic arthritis presents as an acute hot, swollen, painful joint requiring immediate aspiration to exclude infection before any treatment; synovial white blood cell count above 50,000 with high neutrophil percentage suggests infection. Compartment syndrome produces pain out of proportion to apparent injury, pain with passive stretch of involved muscles, and the five Ps (pain, paresthesias, pallor, pulselessness, paralysis) in advanced cases; this is a surgical emergency requiring fasciotomy. Cauda equina syndrome combines low back pain with saddle anesthesia, urinary retention or incontinence, and bilateral leg weakness; emergent MRI and neurosurgical consultation are required. Open fractures with bone exposed through skin wounds require emergent irrigation, debridement, and antibiotics. Appropriate referral decisions guide efficient resource utilization and ensure patients receive needed specialty care. Orthopedic referral is indicated for suspected septic arthritis, complete tendon ruptures, unstable fractures, significant joint instability, suspected cauda equina syndrome, and failed conservative management of structural problems where surgery might benefit. Rheumatology referral is appropriate for suspected inflammatory arthritis (rheumatoid, psoriatic, seronegative spondyloarthropathies), complex gout failing primary care management, systemic autoimmune conditions, and diagnostic uncertainty when inflammatory disease is suspected. Physical therapy referral enhances outcomes for most musculoskeletal conditions through supervised exercise prescription and functional restoration. Panel A: Osteoporosis screening algorithm showing age-based and risk-based recommendations with FRAX integration and treatment thresholds. Panel B: Bisphosphonate treatment overview including agents, administration instructions, and monitoring recommendations. Panel C: Musculoskeletal red flags requiring emergent evaluation organized by condition with key features. Panel D: Referral decision framework for orthopedics, rheumatology, and physical therapy based on clinical scenario. --- ## Summary - Joint pain approach: mechanical (morning stiffness less than 30 minutes, worse with activity) versus inflammatory (stiffness greater than one hour, improves with activity) - Osteoarthritis: mechanical pain affecting DIP, PIP, first CMC, knees, and hips; treat with exercise, weight loss, topical then oral NSAIDs - Gout: acute monoarticular inflammation, first MTP most common; NSAIDs, colchicine, or corticosteroids for acute attacks - Urate-lowering therapy: allopurinol first-line, target uric acid below 6 mg/dL, prophylaxis for first three to six months - Rheumatoid arthritis: symmetric small joint polyarthritis, morning stiffness greater than one hour; early rheumatology referral is essential - Septic arthritis: acute hot swollen joint is aspiration urgent; never inject steroids before excluding infection - Rotator cuff pathology: anterolateral shoulder pain with impingement signs; physical therapy first-line, consider injection - Low back pain red flags: saddle anesthesia, urinary retention, progressive weakness, fever, cancer history, weight loss - Imaging for low back pain is not indicated in first four to six weeks without red flags - Osteoporosis: screen women 65 and older; T-score at or below minus 2.5 indicates osteoporosis; bisphosphonates are first-line treatment --- ## Key Terms | Term | Definition | |------|------------| | Mechanical pain | Pain worsened by activity and improved by rest | | Inflammatory pain | Pain and stiffness improved by activity | | Heberden nodes | Bony enlargement at DIP joints characteristic of osteoarthritis | | Podagra | Gout affecting the first metatarsophalangeal joint | | Impingement | Compression of rotator cuff tendons during shoulder elevation | | Radiculopathy | Pain and neurological symptoms following nerve root distribution | | T-score | DXA result comparing bone density to young adult peak | | Cauda equina syndrome | Surgical emergency with saddle anesthesia, urinary symptoms, and bilateral weakness | --- *This content is subject to the [MIT License](https://opensource.org/licenses/MIT). © 2024–2026 Hibbert School of Medicine.*