Mr. Arthur Ritis, a 52-year-old man with diabetes, hypertension, and a history of gout, presented with a hot, swollen, and painful right knee for 24 hours. Examination found a warm knee with a large effusion and mild tenderness. Blood tests showed elevated white blood cell count and C-reactive protein. Arthrocentesis of the knee found cloudy yellow synovial fluid containing urate crystals on microscopy. This confirms the diagnosis of an acute gout attack in the knee requiring treatment.

1. ARTHROCENTESIS
A STAB IN THE DARK

2. LEARNING OUTCOMES
Arthrocentesis
• Indications
• Contraindications
• Basic technique
• Guided techniques
• Synovial fluid analysis
• Complications
Joint injection
• Use in ED
• Medications

3. Mr Arthur Ritis
• 52 year old man
• 24 hours of hot, swollen,
painful right knee.
• PMHx
T2DM, HTN, A Touch
Overweight, Gout
• Meds
Olmesartan/HCT, Metformin
• NKDA

4. Mr Arthur Ritis
• General Exam
Temp 37.7
Knee
• Warm, large effusion, mild
tenderness
• ROM reduced

5. Mr Arthur Ritis
• Investigations

6. Mr Arthur Ritis
• Blood tests
FBP (WCC)1
CRP2
? ESR1
? Pro-calcitonin3
? uric acid
• Imaging
Plain film Xray

7. Mr Arthur Ritis
• Blood tests
WCC 12.5
CRP 60

8. ARTHROCENTESIS
• Indications
Investigation of
unexplained mono-
articular arthritis.
Confirm diagnosis of first
episode crystal
arthropathies.
Symptomatic tap for
large effusion.

9. ARTHROCENTESIS
• Contra-indications
Non compliant patient
• Relative
Overlying Cellulitis4
Uncontrolled bleeding
disorder5,6
Prosthetic joint

10. ARTHROCENTESIS
• Technique
Sterile gloves
Skin prep
• SCGH ED Guideline
• Springer et al.
Joint Arthrocentesis in the
Emergency Department.

11. ARTHROCENTESIS
UPPER LIMB LANDMARKS

12. ARTHROCENTESIS
UPPER LIMB

13. ARTHROCENTESIS
LOWER LIMB LANDMARKS

14. ARTHROCENTESIS
LOWER LIMB LANDMARKS

15. ARTHROCENTESIS
ULTRASOUND GUIDED

16. ARTHROCENTESIS
SYNOVIAL FLUID ANALYSIS

17. ARTHROCENTESIS
SYNOVIAL FLUID ANALYSIS
Macroscopic assessment
Microscopy
Gram stain7
Crystals
Cell count (WCC, % Polymorphonuclear)7,8
Culture

18. ARTHROCENTESIS
MR ARTHUR RITIS
Macroscopic assessment: yellow, slightly cloudy
Microscopy
Gram stain: no bacteria seen.
Crystals: urate crystals
Synovial WCC: 15000 PMN: 60%
Culture: pending

19. THOUGHTS?

20. STEROID INJECTIONS

21. EVIDENCE
• Osteoarthritis9
• Rheumatoid arthritis10
• Gout 11

22. WHICH STEROID?12

23. REFERENCES
1. Li S, Cassidy C, Chang C et al. Diagnostic utility of laboratory tests in septic arthritis. Emergency Medicine Journal. 2007;24(2): 75-
77.
2. Hugle T, Scheutz P, Mueller B et al. Serum procalcitonin for discrimination between septic and non septic arthritis. Clin Exp Rheum.
2008;26:305-8.
3. Maharajan et al. Serum Procalcitonin is a sensitive and specific marker in the diagnosis of septic arthritis and acute osteomyelitis. J
Orth Surg Research. 2013;8.
4. Dooley DP. Aspiration of the possibly septic joint through potential cellulitis: Just do it! J Emerg Med 2002;23:210.
5. Yui J etal. Arthrocentesis and Joint Injection in Patients Receiving Direct Oral Anticoagulants. Mayo clinic proceedings.
2017;92(8):1223-26.
6. Ahmed I. Safety of Arthrocentesis and Joint Injection in Patients Receiving Anticoagulation at Therapeutic Levels. Am J Medicine.
2012;125(3):265-9.
7. Carpenter C et al. Evidence based diagnostics: septic arthritis. Academic Em Med. 2011;18(8): 782-96.
8. Coutlakis PJ. Another look at synovial fluid leukocytosis and Infection. J Clin Rheumatol 2002; 8:67–71.
9. Godwin. Intra-articular steroid injections for painful knees. Systematic review with meta-analysis. Can Fam Phys. 2004;50(2):241-
248.
10. Wallen M, Gillies D. Intra-articular steroids and splints/rest for children with juvenile idiopathic arthritis and adults with rheumatoid
arthritis. Cochrane Musculoskeletal group. 2006.
11. Wechalekar M et al. Intra-articular glucocorticoids for acute gout. Cochrane musculoskeletal group. 2013.
12. Stephens M et al. Musculoskeletal injections: a review of the evidence. Am Fam Phys. 2008;78(8):971-6.