1.Dr. Ravichandra Yadav

2. Chapter outline Physiology and Composition of Synovial Fluid Specimen Collection Laboratory Testing Macroscopic Evaluation Chemical Examination Microscopic Examination Classification of Joint Disorders 3. Synovial Fluid Synovial = syn (like) + ovia (egg). Synovial fluid is a thick, stringy fluid found in the cavities of synovialjointsWith its egg like consistency .The inner membrane of synovial joints is called the synovial membrane andsecretes synovial fluid into the joint cavity This fluid forms a thin layer [roughly 50 milli microns] at the surface ofcartilage. 4. composition Synovial tissue is composed of connective tissue that lacks a basementmembrane. Two cell types [typeA and typeB ]are present. Type B produces synovial fluid &type A produces hyaluronic acid. Synovial fluid is made of hyaluronic acid and lubricin , proteinases andcollagenases. Normal synovial fluid contains 3-4 mg/ml hyaluronan [hyaluronic acid ], apolymer of disaccharides .composed of D-glucronic acid and D-N acetylglucosamine joined by alternating beta-1,4 and beta-1,3glycosidic bonds. 5. composition Hyaluronan is synthesized by the synovial membrane and secreted into thejoint cavity to increase the viscosity and elasticity of articular cartilages andlubricate the surface between synovium and cartilage. Synovial fluid also contains lubricin secreted by synovial cells. It is chiefly responsible for so called boundary layer lubrication, which reducesfriction between opposing surfaces of cartilage. There is also some evidence that it helps regulate synovial cell growth. 6. functions Reducing friction by lubricating the joint . Absorbing shocks. Supplying oxygen and nutrients to removing carbon dioxide and metabolicwastes from the chondrocytes with in articular cartilage . It also contains phagocytic cells that remove microbes and the debris thatresults from normal wear and tear in the joint. 7. Synovial joint 8. Synovial Fluid Synovial membrane from a normal knee joint showsjoint space,synovial membrane composed of synovial cells embedded in aloose connective tissue stroma overlying dense collagen(hematoxylin and eosin). 9. Synovial Fluid: Physiology andComposition Clear viscous ultra filtrate of plasma Glucose and uric acid equivalent to plasma Protein lower than plasma Hyaluronate protein complex containing mucin Moistens and lubricates joints 10. Bulge testThe Bulge test is used to determine if there is an abnormalamount of fluid surrounding a jointBulge test of joint for the detection of synovialeffusion 11. Synovial Fluid: Specimen Collection(cont.) Needle insertion Placement of needle in arthrocentesis of (A) elbow and (B) knee joints. 12. Laboratory Testing: Macroscopic Volume Color and Clarity Inclusions Viscosity Clotting Mucin Clot 13. Laboratory Testing: Macroscopic Volume Normal up to 4 mL of fluid Result usually recorded at bedside Some laboratories may include volume in reports 14. Macroscopic Analysis: Color and Clarity Colorless and clear normal Red, brown, or xanthochromic hemorrhage into the joint Yellow/clear noninflammatory effusions Yellow/cloudy inflammation White/cloudy crystals 15. Macroscopic Analysis: Inclusions Rice bodies. Free-floating aggregates of tissueappear as rice bodies. rheumatoid arthritis (RA) Degenarated synovium enriched with fibrin Ochronotic shards debris from joint prosthesis look like ground pepperA =ochronotic shardsB= rice bodies 16. Macroscopic Analysis: Viscosity Evaluated using String test Normal = 5cm long before breaking Low viscosity indicates inflammation 17. Macroscopic Analysis: Clotting Clotting of synovial fluid = fibrinogen Damaged synovial membrane Traumatic tap Clots interfere with performance of cell counts 18. Macroscopic Analysis: Mucin Clot Estimation of hyaluronic acidprotein complex integrity the adding of acetic acid to normal synovial fluid, which causes clot formation.The compactness of the clot and the clarity of the supernatant fluid are thecriteria on which the result is based. Evaluated using Ropes test Good = tight ropey mass normal Poor = beaks easily haluronate destruction haluronate dilution 19. Laboratory Testing: Chemical Protein Glucose Uric Acid Lactic Acid Lactate Dehydrogenase Rheumatoid Factor 20. Chemical Analysis: Protein All proteins found in plasma Exception: various highmolecular weight proteins which may be present invery small amount Fibrinogen beta 2 macroglobulin alpha 2 macroglobulin Use common serum protein procedures 21. Chemical Analysis: Protein (cont.) Normal range 1-3 g/dl Increased protein ankylosing spondylitis arthritis Crohn disease Gout Psoriasis Reiter syndrome ulcerative colitis. 22. Chemical Analysis: Glucose Compare to serum glucose levels Normal synovial glucose is no lower than 10mg/dl less than serum glucoselevels. Decreased joint disorders Greater than 20mg/dl decrease may indicate infection 23. Chemical Analysis: Uric Acid Normal - 6 to 8 mg/dL Increased gout May form crystals 24. Chemical Analysis: Lactic Acid Rarely measured in synovial fluid Can be helpful in diagnosing septic arthritis. Normal = less than 25 mg/dL Septic arthritis can show levels up to 1000 mg/dL 25. Laboratory Testing: LactateDehydrogenase May be elevated in synovial fluid, while serum levels remain normal. Increased in Rheumatoid arthritis (RA) infectious arthritis, gout. Neutrophils increased during the acute phase of these disorders contribute tothis increased LD. 26. Laboratory Testing: Rheumatoid Factor RF is an antibody to immunoglobulins. Present in rheumatoid arthritis: Serum most cases Synovial fluid - 50% Rarely elevated only in synovial fluid and not serum False positives in other chronic inflammatory diseases. 27. Laboratory Testing: Microscopic Cell Counts Differential Crystals 28. Microscopic Analysis: Cell Counts Perform within 1 hour of specimen collection Usually counted manually Normal values: RBCs = none WBCs = 0 150/cumm 29. Microscopic Analysis: Differential Cytocentrifuge prepared smears Normal values: Neutrophils 7% Lymphocytes 24% Monocytes (Histocytes) 48% Macrophages 10% Synovial lining cells4% 30. Microscopic Analysis: Differential Normal cellular elements found in synovial fluid 31. Microscopic Analysis: Differential(cont.) Elevated neutrophils: Septic arthritis Later stages of RA ragocytes[a polymorphonuclear phagocyte,] 32. Microscopic Analysis: Differential(cont.) Elevated Monocytes Serum sickness associated arthritis Viral infections Crystal-induced arthritis 33. Microscopic Analysis: Differential(cont.) Elevated lymphocytes: tuberculosis Early stages of RA 34. Microscopic Analysis: Differential LE cells LE cells are neutrophilsthat have engulfed anucleus of a lymphocytethat has been altered byantinuclear antibody Tart cells Tart cells, monocytes thathave engulfednuclearMaterial 35. Microscopic Analysis: Differential Reiter cellsReiter cells are neutrophil-laded macrophages 36. Microscopic Analysis: Differential Differential-Lipophage Lipid-laden macrophage 37. Microscopic Analysis: Crystals-Uric AcidSynovial fluid with acuteinflammation and monosodium Synovial fluid with acuteurate crystals. The needle-shaped inflammation and monosodiumcrystals demonstrate negative urate crystals. (WrightGiemsa birefringence, because they are stain and polarized light).yellow when aligned with thecompensator filter and blue whenperpendicular to the filter (WrightGiemsa stain andpolarized/compensated light). 38. Microscopic Analysis: Crystals-other Synovial fluid with acuteSynovial fluid with acuteinflammation and calciuminflammation and calcium pyrophosphate dihydrate crystals. Thepyrophosphate dihydrate crystals rhomboidal intracellular crystal(WrightGiemsa stain and (center) demonstrates positivepolarized light).birefringence, because it is blue when aligned with the compensator filter (WrightGiemsa stain and polarized/compensated light). 39. Microscopic Analysis: Crystals-other Corticosteroid crystals :crystals are needle-shaped intra-articular injections Cholesterol crystals : chronic effusions from patients withosteoarthritis or RA Apatite crystals :(small chunky rods) calcific periarthritis osteoarthritis inflammatory arthritis 40. Laboratory Testing: Microbiology Infectious organisms Bacteria Fungi Mycobacteria Viruses Route of entry Bloodstream Penetrating wounds Osteomyelitis rupture Arthroscopy intra-articular steroidm injections prosthetic joint surgery 41. Laboratory Testing: Microbiology (cont.) Staining Smears prepared by centrifugation or cytocentrifugation Saline dilution reduces clustering of cells Grams stain most commonPositive in only 50% of cases Culture Set up with positive or negative stain results Aerobic anaerobic 42. Classification of Joint Disorders 43. Pathology Many synovial fluid types are associated with specificdiagnoses Noninflammatory (Group I) Osteoarthritis,degenerative joint disease Trauma Rheumatic fever Chronic gout or pseudogout scleroderma Polymyositis Systemic lupus erythematosus Erythema nodosum Neuropathic arthropathy (with possiblehemorrhage) Sickle-cell disease Hemochromatosis Acromegaly Amyloidosis 44. Inflammatory (Group II) Rheumatoid arthritis Reactive arthritis Psoriatic arthritis Acute rheumatic fever Acute gout or pseuodgout Scleroderma Polymyositis Systemic lupus erythematosus Ankylosing spondylitis Inflammatory bowel disease arthritis Infection(viral, fungal, bacterial) including Lyme disease Acute crystal synovitis 45. Septic (Group III) Pyogenic bacterial infection Septic arthritis Hemorrhagic Trauma Tumors Hemophilia/coagulopathy Scurvy Ehlers-Danlos syndrome Neuropathic arthropathy 46. Review of Key Points Synovial fluid analysis Is a well-established procedure for evaluation of joint disease. Determines the presence of arthritis Assists in the classification of joint disorders Helps guides appropriate treatments 47. Thank you