Arthrocentesis

Question 1

What are the expected synovial fluid findings to indicate:
- Septic
- Inflamm
- Non-inflamm
And what are 2 differentials for each:

Answer 1

Non-Inflamm (<2000, <25%)
–> OA, haemoarthrosis, fracture
Inflamm (2-50,000, >50%)
–> Gout, CPDD, RA, SLE, Rheumatic Fever
Septic (>50,000, >75%)
–> Bacterial, TB.

Question 2

Contraindications to arthrocentesis:

Answer 2

Plts <20
Overlying infection
Prosthetic joint
Fracture

Question 3

Site of arthrocentesis of ANKLE

Answer 3

Plantar flex
Between tib ant tendon and medial mall

Question 4

Site of arthrocentesis of KNEE

Answer 4

Lat, med, infrapat, suprapat approaches

Gently flex
1-2cm lateral to upper third of patella

Question 5

Site of arthrocentesis of SHOULDER

Answer 5

Anterior or posterior approaches

Arm by side, hand in lap
Between coracoid and humeral head

Question 6

Site of arthrocentesis of WRIST

Answer 6

Gentle palmar flex, ulnar deviation
Distal to radial styloid

Question 7

Site of arthrocentesis of ELBOW

Answer 7

Elbow at 90, palm down
Proximal to radial head