Synovial fluid analysis Sarah

Normal synovial fluid

Normal synovial fluid is: • An ultra-filtrate of plasma • Has no clotting factors • Is viscous • Is acellular • Is aparticulate

Why do we do it ?

1. Helps in referring the patient to the right specialist : non-inflammatory : orthopedic , inflammatory : rheumatology

2. Diagnosis : inflammatory vs non-inflammatory , crystals vs exacerbations , prosthetic failure

3. Prognosis : stage of particular disease , orthopedic intervention

4. Monitor therapy 5. Research

Examining the SF specimen

• Gross analysis • Nucleated cell count • The “wet prep” • Preparation and examination of the stained

cell monolayer

Gross analysis

• Color Haemorrhagic episode : trauma , mild trauma in antico- agulant therapy, bleeding due to pigmented villonodular synovitis. • Clarity Cloudy / opaque appearance indicates presence of crystals , proteins , lipids , increased cellular components • Viscosity

Nucleated cell count

• The number of nucleated cells contained in the SF is a prime indicator of inflammation.

• Cell count is less than 500/ mm3 the patient can be assumed to have a non-inflammatory arthropathy

• Cell count is greater than 1500 this would indicate an inflammatory arthropathy.

The “wet prep”

• It is basically used to identify crystals and debris

Crystals Using polarizing microscopy

MSU CPPD

bright birefringent crystals that are yellow (negatively birefringent)

shorter rod shape and often they are rhomboidal or cube shaped. They are.

Preparation and examination of the stained cell monolayer

Using gram-stain of cytological stains to identify cells and organisms