Approach
• Careful hx; anatomic distribution, single vs. multiple joints, acute vs. chronic, a/w fevers, skin changes; h/o trauma
• Eval for systemic sxs in conjunction w/ chief complaint of joint pain
• If considering septic arthritis, evaluate need for arthrocentesis
TENOSYNOVITIS
Definition
• Inflammation of the tendon & tendon sheath. Can result in chronic disability, ↓ ROM, chronic pain, amputation if not treated appropriately.
GOUT
History
• Middle-aged pt w/ abrupt (often recurrent) onset single joint pain, swelling, erythema, warmth; may be precipitated by minor trauma or illness
• RFs: HTN, HLD, DM, obesity. Systemic etiologies: Cancer, hemolysis.
• 75% monoarticular, classically affects 1st MTP joint (aka “podagra”)
Findings
• Red, swollen, tender, warm joint (MTP > ankle > torsal area > knee); mimics cellulitis
• Tophi overlying effected joints indicate chronic gouty dz
Evaluation
• Arthrocentesis if: 1st episode (no prior tap), unclear Dx, concern for septic joint
• Joint fluid: Needle-shaped, negatively birefringent crystals; always send for culture
• Serum uric acid level is of no value; 30% will have nl levels
• X-ray findings in chronic gout include bony erosions, punched out lesions, calcified tophi
Treatment
• NSAIDs (no aspirin). Eg, indomethacin 50 mg PO TID for duration of attack (∼3–10 d).
• Alternatively: Colchicine (0.5 mg PO q1h up to 8 mg; if nl renal fxn) OR steroids
• Allopurinol for chronic prevention but has no role in acute mgmt of gout attack
Disposition
• D/c home w/ pain control unless intractable pain
Pearl
• Gout is a result of monosodium urate crystal deposition
PSEUDOGOUT
History
• Elderly pt w/ abrupt-onset, single-joint pain, swelling, erythema, warmth; precipitated by minor trauma or illness; usually in large joints (unlike gout)
Findings
• Red, swollen, tender, warm joint (knee > wrist > ankle = elbow)
Evaluation
• If unclear Dx, concern for septic joint, perform arthrocentesis
• Joint fluid: Rhomboid-shaped, positively birefringent crystals
• X-ray findings: Chondrocalcinosis, subchondral sclerosis, radiopaque calcifications
Treatment
• Same as gout
Disposition
• D/c home w/ pain control
Pearls
• Pseudogout is the result of calcium pyrophosphate crystal deposition
• Most common cause of new monoarticular arthritis in pts >60 y/o
• RFs: ↑ Ca, ↓ Mg, ↓ PO4, hemochromatosis, hemosiderosis, parathyroid dz
BURSITIS
Definition
• Inflammation of bursa, which are flattened sacs lined w/ synovial fluid that helps facilitate movement; bursitis is usually due to overuse, trauma or osteoarthritis, but can be septic
History
• Discrete area of pain, swelling, erythema, warmth over a joint
• Less than half of bursitis is septic, but 70% of septic bursitis has preceding trauma
• Most common in joints that are subject to repetitive stresses (elbow, knee), but can be deep (hip) esp in setting of instrumentation (eg, acupuncture)
Findings
• Warm, swollen, fluid-filled pocket outside the joint ± erythema
• Tenderness, fever, associated cellulitis suggest septic bursitis
• Should have minimal pain w/ passive ROM; o/w consider septic arthritis
Evaluation
• If any concern for septic bursitis, perform bursa aspiration (WBC >5K is suggestive)
• Deep bursae are aspirated by ortho or IR
• Often clinically difficult to differentiate from septic arthritis; may need arthrocentesis
Treatment
• Rest, ice, elevation, analgesia, ±steroid injection
• If septic bursitis: Abx for Staph coverage (eg, dicloxacillin, TMP–SMX, or clindamycin)
• Consult ortho for f/u as these have high outpt failure rate & may need surgical bursal excision or serial aspirations
Disposition
• D/c w/ pain control if no ortho intervention, ±abx
• Admit for fulminant infection, immunocompromised pt, significant surrounding cellulitis
Pearl
• Prepatellar (carpet layer’s knee) & olecranon bursitis (student’s elbow) are usually due to Staph infection from local trauma
INFECTIOUS
Septic Arthritis (Nongonococcal)
History
• Acute onset of painful, swollen, warm, tender joint, often w/ fever
• Hallmark is severe pain w/ any passive ROM
• All joints are at risk but most commonly knee > hip. In peds, hip is most common.
• High-risk groups include IV drug users, immunocompromised
Findings
• Usually single joint involvement; can see multi-joint in disseminated GC dz
• Pain w/ minimal passive ROM or axial load; warmth, redness, swelling
Evaluation
• X-ray to identify effusion, possible FB, fracture, or osteomyelitis
• Arthrocentesis: Gram stain & culture, cell count, protein & glucose, crystal analysis. Positive: WBC >50000 w/ PMN predominance.
• Labs: Consider ESR, CRP, blood cx to isolate; UA, CXR for infectious w/u
Management
• Arthrocentesis (hip by orthopedics or IR), ortho consult, splint in physiologic position
• Supportive care: Hydration, antipyretics, pain control
• Abx after arthrocentesis & blood cultures taken; S. aureus is most common
• Adults: Vancomycin AND (3rd-generation cephalosporin OR quinolone)
• Children <14: Vancomycin AND 3rd-generation cephalosporin
• Prosthesis, immunocompromised: Vancomycin AND antipseudomonal (piperacillin/tazobactam OR ciprofloxacin)
Disposition: Admit for abx, ortho observation, likely need for operative washout
Pearls
• Septic hips do not present w/ classic signs; can be very subtle
• Presence of crystals in the joint fluid does not r/o a septic joint
• Overlying cellulitis is relative CI for arthrocentesis; avoid cellulitic area
• If hardware is present, discuss risk/benefit w/ orthopedics prior to arthrocentesis
• Intra-articular steroid injection for pain relief in septic arthritis is contraindicated
Gonococcal Septic Arthritis
History
• Young, sexually active pt usually c/o single painful, swollen, warm, & tender joint
• May be polyarticular or migratory; smaller joints (elbow, wrist, ankle) commonly involved
• Urethral or vaginal d/c of GC infection may be present
Findings
• Any clinical manifestations of Neisseria GC infection (cervicitis, malodorous, purulent vaginal d/c in female or dysuria & penile d/c in male)
• Swollen, tender, warm, & extremely painful small joint(s), usually slightly flexed at rest, more painful w/ ROM; may have tenosynovitis
• A painless diffuse maculopapular rash w/ necrotic/pustular centers may be present
• RUQ abdominal pain may indicate Fitz–Hugh–Curtis syndrome
Evaluation
• Same as non-GC septic arthritis + cervical (female) & urethral (male) cultures, pharynx & rectal cultures to ↑ likelihood of definitive Dx
Treatment
• Arthrocentesis, ortho consult, splint joint in physiologic position for comfort
• 3rd-generation cephalosporin (ceftriaxone 1 g IV QD) OR quinolone, add doxycycline for chlamydia
• Supportive care: Hydration, antipyretics, pain control
Disposition: Admit for abx, ortho observation, possible need for operative washout
Pearls
• GC septic arthritis is the only septic arthritis that does not necessarily need operative washout; however, serial arthrocentesis to remove fluid may be indicated
• Gram stain & culture from GC septic arthritis more often negative than non-GC septic joints
• Intra-articular steroid injection for pain relief in septic arthritis is contraindicated.