10/5/2015 The Approach to Acute Knee Effusions ASAPA 2015 Fall Conference Kevin Cantwell, PA-C, Ortho CAQ FastMed Sports Medicine What the EFF(usion)?! Do I Aspirate or not? Do I get an MRI? Do I send to the ER? Overview Discuss Pertinent History Review Anatomy Focused, effective physical exam Review of Aspiration Technique Laboratory Evaluation 1 10/5/2015 Causes Traumatic/Hemorrhagic Patellar Dislocation, ACL tear, fracture Inflammatory Gout, Pseudogout, Rheumatoid Infectious Non-inflammatory Osteoarthritis HPI Injury Mechanism: ie. Direct blow, deceleration, valgus injury, prolonged squatting/twisting Pain versus No Pain Prior history: ie. Gout, patellar instability, arthritis Surgical history: arthroscopic/open Associated symptoms: ie. Polyarthritis, Fever, Conjunctivitis, urethral discharge History Trauma Fracture: Direct blow, age >55yo, inability to walk ACL: non-contact deceleration, cutting movement or hyperextension Meniscus: squatting/twisting, mechanical symptoms Collateral sprain: Patellar Dislocation: twisting force on weight bearing leg Fracture, ACL and Patellar Dislocation: 35-60% cause of hemarthrosis within 4 hours 2 10/5/2015 Knee Anatomy Physical Exam General Appearance (WB/distressed?) Skin: erythema/wounds/warmth Deformity/Guarding/Splinting Active ROM/ Passive ROM (hip, knee, ankle) Straight Leg Raise Popliteal angle Palpation: Suprapatellar fullness/fluctuance, medial patellar fullness Patellar Mobility, Apprehension, Facet Pain Quad tendon or Patellar tendon defect/pain Joint line pain McMurrays Physical Exam Should I bend the knee? Can the patient bend the knee? Perform Straight Leg Raise (SLR)? 3 10/5/2015 Physical Exam Recognizing an Effusion Suprapatellar fullness Medial peripatellar fullness (VMO may look enlarged) Popliteal Angle: resting position 15-25 degrees Effusion versus Bursitis Effusion versus Bursitis 4 10/5/2015 Physical Exam(cont.) Ligament Exam MCL: valgus stress in full extension and at 30 degrees of flexion LCL: Varus stress PLC: External Dial, ER recurvatum PCL: Sag sign and posterior drawer ACL: Anterior Drawer (least reliable) Pivot Shift Lachmans (best for ACL laxity) Physical Examination Always compare to the contralateral leg Best in supine position Tailor the exam to the patient 5 10/5/2015 Imaging X-rays: AP Standing AP Weightbearing/Tunnel/ Intercondylar Lateral Merchant/Sunrise Oblique Imaging Magnetic Resonance Imaging Safe Painless (most of the time) Precise Cost effective? Expensive No contrast needed (unless knee effusion with history of meniscus repair) Aspiration Synovial analysis is sensitive and inexpensive Crystalline arthropathies readily identified Gram stain and culture are diagnostic of infection Alleviates acute symptoms and improves joint mobility Few contraindications 6 10/5/2015 Aspiration Indications Septic joint Crystalline arthropathy Hemorrhagic (trauma/coagulopathy) Chronic arthritis (OA, RA) Contraindications Overlying ulcer/wound Suspected Tumor? Coagulopathy Aspiration Technique Supine Popliteal Bump Betadine, Ethyl Chloride, Alcohol 18-gauge needle with 30-60 cc syringe Aspiration site is provider preference Aspiration 7 10/5/2015 Acute Effusion Labs Synovial Fluid Cell Count Crystals Gram Stain Culture Glucose (decreased with RA, infection) Protein (elevated with RA) Blood CBC with differential ESR, CRP RA work up: RF, ANA, anti-CCP, Synovial Analysis Baker K. ACL tear History of deceleration, cutting or hyperextension injury Typically large effusion Positive lachmans, anterior drawer or pivot shift Xrays typically negative. Possible tibial spine avulsion or lateral Segond fracture Aspirate for pain relief Crutches, hinged-knee brace, ice, encourage ROM MRI Ortho Referral 8 10/5/2015 Gout/Pseudogout Similar to Septic joint Assoc’d with hyperuricemia/hyperparathyroid, hemochromatosis, hypothyroid Monosodium Urate crystals/Calcium Pyrophosphate Previous history (first attack 40-50 yo) High-Purine diet, Diuretic use, increase Etoh = Gout Xrays: Chondrocalcinosis with pseudogout Serum Uric acid may or may not be elevated Tx: Colchicine, Indomethacin (NSAIDs), Consider injection if not septic Inflammatory Rheumatoid Arthritis, SLE, Reactive Arthritis Worse in the morning Better with activity Multiple joints Rash/conjunctivitis/urethritis Xrays: marginal erosions and osteopenia Labs: CRP/ESR/RF/ANA/anti-CCP/HLA-B27 Aspirate: decrease glucose , elevated protein Refer Septic Arthritis Red, hot, swollen knee Knee effusion Fever, chills Severe pain, exacerbated with ROM History/Risk factors: DM, RA, Lupus, HIV, steroid use, immunocompromised, IV drug use, surgery Xrays: no acute findings Refer to ER, Call Ortho for I and D Aspirate/Labs: cloudy, WBC >50,000, PMNs >75-90%, + gram stain/cx 9 10/5/2015 Patella Dislocation Twisting force on weight bearing leg Recurrence rate is low after first time dislocation Usually painful Large effusion, peripatellar/medial knee pain Apprehension Aspiration for relief, fat droplets indicate intra-articular fracture Xrays: Osteochondral fracture of medial facet or lateral trochlea; trochlear dysplasia; patella alta MRI: Evaluates for osteochondral fracture Tx: Crutches, patellar stabilizing brace. No OC fx->PT Ortho referral Osteoarthritis Pain with use, relief with rest PF: pain with prolonged sitting Previous exacerbations History of trauma Effusion, erythema and warmth with exacerbations Pain much less and ROM much better compared to Septic Joint Xrays: joint space narrowing, osteophyte formation Aspirate: clear, <200WBC, <25% PMNs Activity modification, NSAIDs, Injections Peds Well Child With History of Without Trauma significant trauma Mechanical Bleeding Fractures Derangements Disorders/Neoplasia 10 10/5/2015 Peds Sick Child Febrile Afebrile Partially treated Acute Rheumatic Sepsis Septic Arthritis Fever Malignancy Kawasaki Disease Sickle Cell Connective Tissue Disorder Resources X-Rays Views 11 10/5/2015 Alogrithm Synovial Analysis Baker K. Differential Miller Orthopedics 12 10/5/2015 Differential 13.