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Conflict of Interest

Assessment and Care of a I hereby certify that, to the best of my knowledge, no aspect of my current Knee Effusion for an personal or professional situation might Advance Practice Nurse reasonably be expected to affect significantly my views on the subject on which I am presenting. Pamela Fruechting, PhD, FNP-BC, ONP-C

Learner Outcome Objectives

1. Name the four types of knee effusions. Upon completion of this educational activity, 2. Identify knee effusions that are associated with increased morbidity and mortality. the learner will : 3. Develop a differential diagnosis based on key critical elements of history and examination. Implement quality-focused, evidence-based care 4. Recognize common errors in diagnosis. 5. Determine which diagnostic tests are most strategies with confidence when assessing appropriate. and treating a patient with a knee effusion. 6. Understand how the etiology of a knee effusion directs the treatment plan.

What is an Effusion? Significance of a Knee Effusion

• An effusion is the overproduction of synovial • A joint effusion is the most specific sign of joint fluid. inflammation. • It is always intra-articular. • Underlying pathology may be benign, malignant, acute, chronic, genetic, traumatic, degenerative, • It may occur acutely, subacutely, autoimmune, infectious, inflammatory, metabolic, or intermittently, with pain, or without pain. any combination of these.

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Three Key Points about Effusions

1. The acuity of a knee effusion does not correlate with the severity of the underlying pathology. Morbidity & 2. The size of a knee effusion does not correlate with the severity of the underlying pathology. Mortality 3. A history of acute or remote trauma, knee surgery, or osteoarthritis, does not preclude a systemic disorder as the etiology of the knee effusion.

Morbidity & Mortality • “High-Stakes” knee effusions: – Autoimmune disease – Fracture (traumatic or pathologic) Four Types of – Malignancy – Septic arthritis Knee Effusions • 30% have functional loss • Up to 30% mortality rate • Loss of function, joint damage, loss of limb, sepsis, death

Four Types of Knee Effusions NON-INFLAMMATORY EFFUSIONS (Taxonomy based on Underlying Disorder) Etiology Joint Onset Trigger Trauma Mono Immediate Acute or • Non-Inflammatory repetitive trauma

• Inflammatory Degenerative Mono Gradual Chondral damage

• Hemorrhagic Tumor Mono Gradual Primary or -Benign metastatic • Infectious -Malignant infiltration Metabolic or Poly Acute Fragility fractures Genetic Disorder Subacute

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HEMORRHAGIC EFFUSIONS INFLAMMATORY EFFUSIONS Etiology Joint Onset Trigger for Effusion Etiology Joint Onset Trigger Trauma Mono Acute Ligament tear, fracture, vessel injury RA Mono-Poly Sub-acute Autoimmune response Anticoagulants Mono Acute Abnormal function of normal Recurrent Hemophilia Sub- clotting pathways Gout Mono Immediate Uric acid derangement; ASA Acute crystals Omega-3, Vit. E Reactive Asymmetric Immediate Enteric infection, Pigmented Mono Acute Synovial neoplasm, non-malignant Arthritis Poly urethritis, uveitis,or STD 2- villonodular 4 weeks prior to joint synovitis effusions Septic Mono Acute Bacterial pathogen most arthritis common

Reactive Arthritis Five Sub-Types of Effusions ~Etiology~ • Reactive arthritis • Septic arthritis An inflammatory joint response to extra-articular • Gonococcal arthritis rather than intra-articular microorganisms. • Malignant effusion • Osteosarcoma • Seronegative sponyloarthropathies - HLA-B27 antigens • Post-infectious causes – GI/GU infection (UTI, STD, IBS, infectious diarrhea)

Reactive Arthritis: Neisseria gonorrhoeae The Symptom Triad • Young, healthy, sexually active Knee or Ankle Effusion • Migratory arthralgias, tenosynovitis, or nonerosive arthritis REACTIVE • Synovial fluid cultures positive in only 50% ARTHRITIS • Mucosal cultures usually positive • Polymerase Chain Reaction (PCR) test Tendinitis Conjunctivitis

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Malignant Effusions: Pathology Osteosarcoma

• Most common bone tumor • Third most common pediatric cancer • Primary malignancy of synovium • Peak incidence 10-20 years of age • Synovial metastasis • Male:Female = 3:2 • Articular metastasis • Patient commonly reports coincident activity-related disorder • 30% of patients have knee effusion • Palpable mass or firmness of soft tissue • Bone biopsy is diagnostic

Septic Arthritis: Statistics Septic Arthritis: Risk Factors

• 2-10/100,000 in general population – Immunocompromised patients • 30-70/100,000 in RA patients – Chronic illness • Knee is most common site – 50% of cases – Pre-existing arthritis • Usually monoarthritis – Prior knee surgery – especially knee replacement – Trauma, even minimal trauma • Polyarticular arthritis - 10-20% of cases – Sexually transmitted disease – IV drug users – Recent intra-articular steroid injection – Infective endocarditis

Septic Arthritis Bacterial Pathogens Septic Arthritis: Viral Pathogens • Viral Arthritis Staphylococci 40% – Rubella Streptococci 28% – Hepatitis B & C Gram-negative bacilli 19% – Parvovirus – HIV Mycobacteria 8% • Unique Symptoms of Viral Arthritis Gram-negative cocci 3% – Acute polyarthritis Gram-positive bacilli 1% – Fever – Rash Anaerobes 1%

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Septic Arthritis: Lyme Disease

• Lyme Disease ( Borrelia burgdoferi ) – Tick exposure – Travel to endemic areas Diagnostic Data – Chronic monoarthritis and synovitis of knee • Unique Symptoms of Lyme Disease – Erythema chronicum migrans/Bull’s eye lesion – Transient polyarthralgias – Systemic symptoms

Diagnostic Data: History Key Elements: Historical Data

Symptoms History

Exam Tests Medical History Family

Diagnosis Exposures

Key Elements: Symptom History Key Elements: Medical History

– Monoarticular or polyarticular involvement • Known diagnoses and medications – Temporal factors • Suspected diagnoses in past – Previous episodes • Nutritional status – Pain level and quality • Surgical procedures and complications – Night pain • Hospitalizations – Perceived disability • Tobacco, ETOH, drugs, tattoos, sexual history – Recent skin, oral, or genital ulcerations/injuries – Systemic symptoms (complete review of systems)

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Key Elements: Family History Key Elements: Exposures • Autoimmune disorders • Recent body wounds or ulcers • Osteoarthritis • Pets and farm animals • Gout • Crowded or unsanitary living conditions • Cancer • International travel • Needle-sharing • Diabetes • Sexual partners Bleeding disorders • • Environmental: • Metabolic bone disorders – Contaminated drinking water • Genetic disorders – Lakes, streams, wooded areas

...the Story Most Important • How the story progresses Historical Data – Evolutionary data – Require frequent follow-up is... • Adjust the differential diagnosis accordingly

Historical Clues: Traumatic Effusion

Historical Clues • Monoarticular • Onset: Immediately to the Etiology of • Mechanical symptoms – Inability to bear weight – Clicking, locking, instability Effusions – Loss of motion • Discrete event – High velocity impact – Twisting injury – “Pop”

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Historical Clues: Historical Clues: Inflammatory Effusion Degenerative Effusion • Monoarticular • Monoarticular • Onset: Days • Minimal effusion • No acute injury • Onset of effusion • Often proportional to weight-bearing activity • Possible overuse history • Improves with rest • Pain at rest, worse with weight-bearing • Early sign: Complaint of posterior knee tightness or • History of prior episodes if autoimmune fullness disorder or gout • Other: Older age, obesity, prior knee trauma or surgery, family history of OA

Historical Clues: Hemorrhagic Effusion Historical Clues: Septic Arthritis

• Onset of effusion: 4-6 hours • Monoarticular • Joint trauma • Onset of effusion: Few hours to days • Very minor trauma: “I stepped wrong”, “I was swimming” • Infectious etiology clues • Drugs and supplements that enhance bleeding – Recent/subacute trauma with worsening symptoms – Omega 3, Vitamin E – Prednisone and other immunosuppressant drugs – Aspirin – Abnormal joint structure (trauma, surgery, OA, RA, – NSAIDS TKA) • Anti-coagulation therapy – Constitutional symptoms • Coagulopathy – Immunocompromise – IV drug use – Sexual history

Historical Clues: Tumor Diagnostic Data: Exam

• Monoarticular • Onset of effusion: Gradual; progressive History • Pain – Constant – May vary with activity Exam Tests • Classic tumor symptoms – Night pain/sweats – Negative trauma history Diagnosis – Unintentional weight loss

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Key Elements: Exam Data COMPARISON OF EXAMINATION DATA

Compare Trauma Septic Arthritis RA/Gout Hemarthrosis OA Extremities Pseudogout Physical Wt bear pain Global pain Joint Pain Joint Pain Joint Pain Exam Deformity WB pain Synovitis Warmth Wt bear pain Ecchymosis Constant pain Warmth Erythema Crepitus Guarding Warmth
AROM Ecchymosis Varus-valgus Effusion Periarticular
AROM Erythema Valgus
AROM Swelling Exam Exam Guarding
AROM

Effusion 2-3+ for ACL 1-3+ 1-3+ 1-3+ Trace-1+ Size tear & intra- Occas. 2+ articular fx Weight- Bearing

Diagnostic Data: Tests Key Elements: Test Data

Imaging History

Synovial Exam Tests Lab Fluid Tests

Diagnosis Evolution

Key Elements: Peripheral Labs RADIOGRAPHIC FEATURES Trauma Septic Arthritis RA/Gout Hemarthrosis OA • Inflammatory and Septic Effusions Pseudogout – CBC, ESR, CRP Fracture Normal RA: Marginal Normal
Joint space Dislocation Degenerative erosions Degenerative Osteophytes • Autoimmune Disorders
Joint space Advanced Valgus Varus-valgus – RF, ANA, HLA-B27, anti-CCP erosive changes later CPPD menisci • Septic Effusion Additional Imaging Blood cultures MRI, CT None None None None – • Other – Uric acid

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Key Elements: Key Elements: Evolutionary Data Evolutionary Data • Critical Analysis of Evolutionary Data • Evolutionary data is dynamic data – Review, retell, & reconstruct the story at every turn – It begins with the remote past, not just recent past – Evaluate the chronological symptom:treatment pattern – Reveals atypical stories and patterns of symptoms – Conduct a review of systems at each patient encounter – Facilitates reordering of the differential diagnosis list – Interview others: Family members, physical therapist, work comp RN – Requires a perpetual open mind – Investigate, and never discard, atypical data – Requires frequent phone or clinic follow-up to capture subtle but significant data that might otherwise be lost – Coincidental data may be your most critical diagnostic clue – Beware of agreeing with patient’s explanations

Synovial Fluid Analysis: Purpose

• Rule out systemic disease process, malignancy, Synovial and septic arthritis. • Distinguish between inflammatory and non- Fluid inflammatory processes. • Identify septic pathogens. Analysis • Identify crystalline disease.

SYNOVIAL FLUID ANALYSIS TYPE OF EFFUSION Key Elements: Synovial Fluid Analysis WBCs PMNs Crystals Culture • Synovial fluid analysis: Non-Inflammatory – White cell count and neutrophil count Trauma < 200 <25% Negative Negative – Gram stain Osteoarthritis < 200 <25% Negative Negative – Culture: Bacterial (aerobic and anaerobic), fungal, Inflammatory mycobacterium (TB) Rheumatoid 2K-50K >50% Negative Negative – Crystals Arthritis Gout/Pseudogout 2K-50K >50% Positive Negative Septic Arthritis > 50K >75% Negative Positive Septic Arthritis: Variable – >65% Negative Positive Prosthetic Joint Low

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SUMMARY OF DIAGNOSTIC TESTING INDICATIONS FOR KNEE ASPIRATION Etiology OnsetHistorical Unique Imaging Clues Synovial Other Tests Features Tests Fluid PURPOSE INTENTION GOAL ASSUMPTION NOTES Analysis Therapeutic Decompression Comfort Any effusion Delay if INR high or Traumatic Immediate Incident XR PRN MRI; CT (fx) signs of bleeding Septic Acute or Abnormal jt XR Yes CBC, CRP, ESR Decompression + Comfort Sterile Effusion Intra-articular Arthritis subacute Trauma? CMP Lidocaine or volume: 5-10 ml. Immuno- Bupivicaine compromise Blood cultures Hemarthro- 4-6 hours Anticoag Rxs XR. Yes PT/INR/PTT, PLT Decompression + Efficacy of Sterile Effusion *Contraindicated sis Coagulopathy R/O fx, ACL tear Corticosteroid * injectable in Septic Arthritis OA Insidious WB pain XR PRN - Decompression + Efficacy of Sterile Effusion *Contraindicated Viscosupplement * injectable in RA RA Acute Synovitis XR Yes ESR, CRP Gout Recurrent Diuretics XR Yes Crystals, Uric acid Diagnostic Synovial Fluid Diagnosis Atypical Effusion Diagnosis in Tumor Insidious Night pain XR, MRI Yes Biopsy Analysis Septic Effusion question Overuse Acute Activity XR, MRI PRN - Correlation

Aspiration Usually Not Necessary When... When is • Acute trauma (<1 week) with no atypical Aspiration Not symptoms • Subacute trauma that is improving as expected • Patient known to you with previous non-septic Necessary? diagnosis, with no significant variance of symptoms

From Data to Diagnosis Development of a History Differential Exam Tests Diagnosis Diagnosis

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Start with the Goal: Key to Effective Treatment Effective Treatment

• Failure to make a correct diagnosis leads to inappropriate treatment. • Inappropriate OR delayed treatment may result in decreased knee function, loss of limb, ACCURATE DIAGNOSIS! even loss of life.

Two Good Rules to Follow The Textbook Diagnosis is Easy

1. All patients with acute effusion of unknown • Traumatic effusion after recent, discrete injury. cause or with atypical history/evolution • Hemorrhagic effusion in warfarin patient. should have synovial fluid analysis. • Inflammatory effusion in RA patient with acute symptom flare. 2. Rule out septic arthritis in any patient who has chronic joint disease or significant co- • Noninflammatory, recurrent effusion in untreated meniscal tear. morbidities. • Septic knee with large effusion, fever, painful weight- bearing, erythema, warmth, and decreased motion.

The Problem is... How Can We

• Patients are often ATYPICAL- Prevent High – They don’t fit the textbook description. Stakes Diagnostic • Waiting for your patient to exhibit textbook symptoms can have devastating outcomes. Errors?

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Origins of Diagnostic Errors Think: “High-Stakes Game”

• Over-reliance on textbook descriptions. • Is my patient an “outlier”? • Failure to consider all aspects of the history. – Atypical data • Failure to recognize the significance of the evolution • Outliers in statistics are discarded or explained away. of the patient’s course. • BEWARE of discarding patient data in diagnostic dilemmas • Failure to believe your patient may be an “outlier” – What is the worst possible diagnosis for this patient? (an atypical patient). – What is the outcome if the “outlier” is ignored? • Failure to rule out a “high-stakes” diagnosis. – What test data do I need? • Failure to be fully available to your patient. – How soon do I need that data?

Beware of “Normalizing” the “High-Stakes” Knee Effusions Atypical Patient • Problem: The diagnosis is elusive • “High-Stakes” effusion: Any effusion in which • Error: “Normalize” the patient by assigning a a missed diagnosis may quickly result in common diagnosis significant morbidity and mortality. Such as: • How does this happen? – Septic arthritis – Discard atypical data – Malignancy – Do not search for subtle, nuanced data – Autoimmune disorder – Fill in data gaps with erroneous assumptions – Coagulopathy – Failure to analyze and follow the evolutionary data • Rule out these diagnoses first.

Know the Red Flags Systemic Inflammatory Response Syndrome (SIRS) • Worsening symptoms when improvement is expected, regardless of age/symptom history Requires at least two of the following criteria: • Sudden or progressive onset of severe knee pain and swelling, often at night • Body temp < 96.8 (36 C) or >100.4 (38 C) • Extra-articular symptoms • Heart rate > 90 bpm • Steroid exposure (intra-articular & systemic) • Respiratory rate > 20 or PaCO2 < 32 mm/Hg • Temporal association of other diseases • WBC < 4000 or > 12000 or >10% bands • Presence of significant co-morbidity • Development of systemic symptoms, including SIRS...

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Know What Test Data You Need • Synovial fluid analysis for: – Anyone with risk factors – Anyone with atypical history or atypical evolution • Vital signs • XR/MRI for atypical extra-articular pain/mass • Lab work-up: – Septic arthritis: CBC, CRP, ESR – Inflammatory disorder: RA work-up, uric acid – Outdoor exposure risk: Lyme disease – Sexually active: STD work-up

Best Skill for Accurate Diagnosis: What is the Single Evolutionary Assessment Develop your evolutionary assessment skills! – Learn the RED FLAGS for each diagnosis Best Skill for – Learn to identify the earliest signs and atypical signs – Know the pathophysiology of knee disorders Accurate – Learn the nuances inherent to each diagnosis – Master knee anatomy & arthrocentesis skills – Practice comprehensive evaluation Diagnosis? – Know what’s at stake in the long-run – Re-evaluate the patient and data frequently

Knee Anatomy – Anterior View of Right Knee Knee Anatomy – Lateral View of Right Knee

https://upload.wikimedia.org/wikipedia/commons/0/04/Blausen_0596_KneeAnatomy_Front.png https://commons.wikimedia.org/wiki/File:Blausen_0597_KneeAnatomy_Side.png

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Goals of Treatment • Maintain joint integrity & joint function • Treat underlying systemic disorders Treatment • Anticipate quandaries and complications • Patient comfort Plan • Timely follow-up – Evolutionary data tracking • EARLY referral • Patient education

Acute Knee Effusion: Treatment Beware of Atypical Evolutions

Type of Weight- Splinting Arthrocentesis NSAIDS Steroid 1. Patient needs stronger pain medication Effusion Bearing for Decompression Injection 2. Failure to respond favorably to treatment Non- Full No Yes Yes Yes, except Inflammatory prosthetic 3. Knee symptoms worsen joints Inflammatory Partial- As needed Yes Yes Yes 4. Systemic symptoms emerge Full Hemarthosis None Yes Yes No No Septic None Yes Yes Yes No Traumatic None- Yes Yes Yes Not for Do you have the wrong diagnosis? Partial fracture or surgical patients

Atypical Evolution: Management Septic Arthritis: Treatment

Management Options: • The most important predictor of outcome is • Aspirate immediately with STAT analysis timeliness of treatment. • IM or IV antibiotics – Best outcome: Patients treated within 7 days of • Advanced imaging if indicated onset • No intra-articular steroids or viscosupplements – Worst outcome: Patients treated after 1 month of onset • Immediate referral: Orthopedist, infectious disease, rheumatology • Septic arthritis is a medical and surgical • Send to ER: Systemic symptoms &/or co-morbidities emergency .

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Corticosteroid Injections: Septic Arthritis: Antibiotics Warnings • Consult infectious disease specialist • Intra-articular corticosteroids may be systemically absorbed. • Start antibiotics before culture results • Consider ALL sources of steroids patient is available receiving. – Empiric therapy: Vancomycin • Complications of steroid use (any source): IV antibiotics for 4-6 weeks is typical – Immunocompromise, including infection • – Adrenal insufficiency • CBC, ESR, CRP monitored until normal • Must rule out septic arthritis before injection. • Do not inject an infected joint. • Do not inject a previously infected joint.

Case Studies: Case Study #1 65 year old male farmer, excellent health, negative joint history. Moderate knee pain and What 2+ effusion began 2 days after doing a lot of Really shoveling. XR: Mild medial joint narrowing. Diagnosis: OA. Rx: RICE, NSAIDS. At 0500 on Happened ... day 5, he awoke with excruciating pain, swelling, and low-grade fever. Diagnosed in ER with septic knee.

Case Study #1: Diagnostic Errors Case Study #2 65 year old male farmer, excellent health, negative joint history. Moderate knee pain and 2+ effusion began 2 45 year old fit and active female strained her knee days after doing a lot of shoveling . XR: Mild medial while lifting a box. Immediate pain and swelling. joint narrowing . Diagnosis: OA . Rx: Rest, NSAIDS. At PMH: Asthma. Remote hx of narcotics addiction. 0500 on day 5, he awoke with severe knee pain and swelling. Diagnosed in ER with septic knee. Day 2: Dx: Knee sprain (crutches PWB, Aleve) Ignored data: Minor ache & no effusion for 2 Day 7: NSAIDS & crutches helped for 2 days. days, then progressed to moderate pain & 2+ Worsening pain, requesting Norco 7.5. effusion 2 days later; shoveling = joint trauma Heightened pain response on exam. D/C Aleve. Rx: Mobic 15 mg qd. Continue crutches. Start PT.

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Case Study #2 (continued) Case Study #2 (continued) Day 12: Tearful – severe pain. PT is “killing me”. Requesting narcotics and sleep agent. Exam Day 17: Found unresponsive at home. To ER. unchanged. Rx: Tramadol 50 & Tylenol PM. Day 19: Died. Continue crutches. PT: Modalities prn. Autopsy: Cause of death: Sepsis Day 15: Complaint of dyspnea and fatigue. Dx: Etiology: Septic knee Asthma exacerbation. Rx: Breathing treatment; inhaler prn. Knee not evaluated.

Case Study #2: Diagnostic Errors Case Study #2 – Diagnostic Errors Day 12: Tearful – severe pain . PT is “killing me” . 45 year old fit and active female strained her knee Requesting narcotics and sleep agent . Narcotic while lifting a box. Immediate pain and swelling. addiction hx . Rx: Tramadol 50 & Tylenol PM. PMH: Asthma. Remote hx of narcotics addiction . Continue crutches. PT: Modalities prn. Day 2: Dx: Knee sprain (crutches PWB, Aleve) Day 15: Complaint of dyspnea, fatigue, and Day 7: NSAIDS & crutches helped at first. malaise . Worsening pain, requesting Norco 7.5 . Dx: Asthma exacerbation . Rx: Breathing Heightened pain response on exam. D/C Aleve. treatment; use inhaler prn. Knee not evaluated . Rx: Mobic 15 mg qd . Continue crutches. Start PT.

Case Study #2 (continued) Case Study #3

Day 17: Found unresponsive at home. To ER. • A 16 year old male, star football player Day 19: Died. • Left ankle injury 4 days ago • Knee swelling 2 days later Autopsy: Cause of death: Sepsis Etiology: Septic knee • Diagnosis: Left ankle sprain and right knee sprain. Treatment: NSAIDS, rest, PT, ankle brace. • What data did the NP assume?

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Case Study #3: Presumed Data Case Study #3: Hidden Data

• Erroneous data (assumed): • Hidden data – Healthy – Knee effusion was not related to an injury. – Sprains/strains “safe” diagnosis for athletes – Knee was not painful which is inconsistent with an – He didn’t complain much because he wants to get injury etiology. back in the game this week. – NP missed important information when he did not – Patient and parents revealed all pertinent health review ROS checksheet. information with NP.

Case Study #3: Abnormal ROS Case Study #3: Outcome

• NP assumed normal ROS and therefore did • MRI ankle: Peroneus brevis tenosynovitis not inquire of patient. Missed data: • 1 week later: Patient developed conjunctivitis • Truth: UTI, hematuria, and elevated creatinine 3 weeks • Dx: Reactive arthritis, HLA-B27 positive (more likely ago. Treated with antibiotics and cystoscopy. to have chronic symptoms) • Truth: Decreased appetite leading to 10 lb. weight loss over 3 weeks, which parents attributed to the UTI • Rheumatologist advised at least six months of recovery. no sports Truth: Recent fatigue, which his parents attributed to • ? collegiate football scholarship psychological stress of recruiters and academic – demands.

Successful Management of Patients with Knee Effusion 1. Know how to identify the at-risk patient. 2. Watch out for the atypical patient. 3. Assess the evolutionary data often. 4. Maintain a high index of suspicion for the QUESTIONS or COMMENTS? “high-stakes” effusions. 5. Aspirate early! 6. Refer promptly!

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References References

1. American Academy of Orthopaedic Surgeons (AAOS) (2009). 5. Geier, K. A. & Benham, A. J. (2015). Musculoskeletal injections in primary Orthopaedic knowledge update: Musculoskeletal infection. G. Cierny III, care. Journal for Nurse Practitioners, 11 (10), pp. 968-978. A. C. McLaren, & M. D. Wongwarat (Eds.) Rosemont, IL: AAOS. http://www.npjournal.org/article/S1555-4155(15)00797-7/pdf 2. Cardone, D. A. & Tallia, A. F. (2003). Diagnostic injection of the hip and 6. Horowitz, D. L., Katzap, E., Horowitz, S., Barilla-LaBarca, M-L. (2011). knee. American Family Physician 2003;67:2147-52. Approach to septic arthritis. American Family Physician, 84 (6), pp. 653- http://www.aafp.org/afp/2003/0515/p2147.html 660. 3. Ferri, F. F. (2016) Ferri’s Clinical Advisor. Section III: Clinical Algorithms: http://www.aafp.org/afp/2011/0915/p653.html http://www.aafp.org/afp Infections of soft tissue, joints, and bone (p. 1561); Inflammatory arthritis /2011/0915/p653.html Excellent overview with empiric antibiotic (p. 1562); Joint effusion (p. 1566); Joint pain and swelling (p. 1567). guidelines Philadelphia, PA: Elsevier. 7. Johnson, M. (2000) Acute Knee Effusions: A Systematic Approach to Diagnosis. American Family Physician 61 (8):2391-2400. 4. Ferri, F. F. (2016) Ferri’s Clinical Advisor. Section IV: Laboratory Tests: http://www.aafp.org/afp/2000/0415/p2391.html Useful diagnostic Synovial fluid analysis (p. 1680-81). Philadelphia, PA: Elsevier. algorithm “Examination of the Swollen Knee” based on exam, radiographs, and arthrocentesis.

References References

8. Roberts, W. N. (2015). Joint aspiration or injection in adults: Technique 12. Zuber, T. J. (2002). Knee joint aspiration and injection. American Family and indications. UpToDate, April 24, 2015. Physician, 66 (8), pp. 1497-1500. http://www.uptodate.com/contents/joint-aspiration-or-injection-in- http://www.aafp.org/afp/2002/1015/p1497.html Good article on adults-technique-and-indications?source=see_link techniques for aspiration/injection. 9. Shirtliff, M. E. and Mader, J. T. (2002). Acute septic arthritis. Clinical Microbiology Reviews, 15 (4), pp. 527-544. doi: 10.1128/CMR.15.4.527– 544.2002 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC126863/ 10. Siva, C., Velazquez, C., Mody, A., & Brasington, R. (2003). Diagnosing acute monoarthritis in adults: A practical approach for the family physician. American Family Physician, 68 (1), pp. 83-90. http://www.aafp.org/afp/2003/0701/p83.html 11. Wheeless, C. R., III. (2015). Wheeless' Textbook of Orthopaedics. http://www.wheelessonline.com

THANK YOU!

Pamela Fruechting, PHD, FNP-BC, ONP-C

[email protected]

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