1What is the space in between two bones (ex. Shoulder meeting arm)
synovial cavity
2What is the purpose of fluid in synovial cavity?
reduces friction, lubricant, lessens shock of joint compression
3What is gouty arthritis?
sharp uric acid crystals build up, like glass shards in between joints
4What are synovial joints?
connecting 2 bones that move against each other. (Ex. Femur and tibia)
5What are diarthroses?
movable joint (thanks to lubrication)
6How is synovial fluid produced?
via synoviocytes in synovial membrane that secrete hyaluronic acid
7What is the purpose of hyaluronic acid?
makes the synovial fluid viscous (for lubrication)
8How does synoviocytes produce synovial fluid?
by filtering plasma through to the synovial cavity
9What are the 4 classification of disorders (arthritis)?
1. noninflammatory
2. inflammatory
3. septic
4. hemorrhagic
10What is noninflammatory arthritis?
degenerative, osteoarthritis
11What is osteoarthritis ?
no immunological reasons, result of wear and tear (natural aging)
no medical treatment
12What is inflammatory arthritis?
What there are an increase of WBC (specifically neutrophils)
13Inflammatory arthritis causes:
immunologic, lupus erythematosus (LE), rheumatoid arthritis (RA), Lyme disease
14What causes lyme disease
Borrelia (ticks)
15What is lupus?
problem with kidney, joint, and connective tissues
16What is the composition of synovial fluid?
Monocytes (~60%), Lymphocytes (30%), & Neutrophils (~10%)
17How can you determine inflammatory arthritis if the WBC remains the same?
need to look at neutrophils, even if WBC remains the same, the ratio of neutrophils may change to ~80% total of WBC
18What kind of arthritis is gout / pseudogout?
inflammatory arthritis
19What causes septic arthritis?
microbial infection in joints
20What is an example of septic arthritis?
septicemia: blood poisoning by bacteria
indicated by cloudy streaks of blood
21What causes hemorrhagic arthritis?
trauma, tumors, coagulation deficiencies
22What is an example of hemorrhagic arthritis?
hemophilia (cannot clot blood), chronic bleeding in joints
also can be due to traumatic accidents (ex. Knee crushed)
23What is the normal volume of synovial fluid?
<3.5 mL
24What is the color of synovial fluid?
colorless to pale yellow
25What is the clarity of synovial fluid?
clear
26What is the viscosity of synovial fluid?
able to form a 'string' 4-6 cm long
(the drop held between fingers can stretch 4-6 cm)
27What is the leukocyte count in synovial fluid?
<200 cells / uL
28What is the neutrophils count of synovial fluid?
<25% of differential
29What is the glucose level in synovial fluid?
<10 mg/dL lower than blood glucose level
30What is the total protein of synovial fluid?
<3 g/dL
31Why is the total protein in synovial fluid low?
because large molecules cannot cross the membrane
32What is needle aspiration called?
arthrocentesis (drawing fluid from joint for analysis)
33What is the normal knee fluid amount?
3.5 mL (but more than 25 mL when inflamed)
34Why doesn't normal synovial fluid clot?
because fibrinogen, the main clotting protein, cannot get into the cavity
35When does synovial fluid clot?
when there is damage to the membrane and fibrinogen can enter
36What are the 3 tubes for synovial fluid?
#1: CHEMICAL&Immunologic, no anticoagulant
#2: MICROSCROPIC, anticoagulant
#3: MICROBIOLOGICAL, STERILE heparinized anticoagulant
37What is unique of anticoagulant for synovial fluid?
needs to be LIQUID EDTA, because powder will form crystals and lead to artifacts
38Why should you test synovial fluid ASAP?
to avoid cellular lysis and changes in crystals (keep at room temp)
39What does deep yellow with green tinge indicate for synovial fluid?
infection
40What does red synovial fluid indicate?
Hemorrhagic or traumatic tap ; homogenous distribution of blood in tube
41What does septic synovial fluid look like?
has blood streaks, Nonhomogeneous
42What is the cause of milky synovial fluid?
crystal induced
43What can turbid synovial fluid indicate?
white blood cells, cellular debris, or fibrin (inflammatory)
44What is essential for joint movement?
hyaluronic acid
45What does arthritis decrease?
polymerization of hyaluronic acid
46What does the mucin clot test indicate?
whether or not the sample is synovial fluid
47How is the mucin clot test done?
dilute fluid with 2% acetic acid: 1-part fluid and 4-parts acid (1:5 dilution)
48When is the fluid confirmed as synovial fluid form mucin clot test?
when hyaluronate from joint fluid forms a clot in the acetic acid
49What are ochronotic shards and what can they indicate?
brownish specks in synovial fluid; can indicate alkaptonuria
50What can rice bodies indicate?
rheumatoid arthritis
51What are the most common cell counts in synovial fluid?
WBC
52What do you use to dilute synovial fluid for cell counts?
normal saline / methylene blue
53If the synovial fluid is viscous, what should you do before cell count?
treat with hyaluronidase
54What is the septic WBC counts in synovial fluid?
>100,000 WBC/ uL (normal is <200 WBC/ uL)
55In septic fluid count, what kind of WBC are most present?
neutrophils
56What are the normal cells present in synovial fluid?
monocytes, macrophages, synovial tissue cells (ratio changes based on age/status of patient)
57What % of neutrophils are expected in cell count?
<25%, but can increase in sepsis
58What % of lymphocytes are expected in cell count?
<15%, but increases in osteoarthritis
59What cell do you see the most in inflammatory joint disease?
neutrophils
60What do you see in haemarthrosis?
macrophage that is phagocytosing RBC, meaning that the bleeding is chronic (erythrophagocytosis)
61When do you see osteoclasts?
when there is damage to the cartilage and the bone is exposed
62What are Reiter cells/neutrophages?
vacuolated macrophages with ingested neutrophils (eating neutrophils)
63What condition can you see Reiter cells?
rheumatoid fever, macrophages are phagocytosing neutrophils (neutrophagia)
64What are ragocytes (RA) cells?
neutrophils with small dark granules containing RA factor (IgM) <- RA factor
65What disease can you find ragocytes?
rheumatoid arthritis
66What are present in crush injuries?
lipid droplets
67What does hemosiderin granules suggest?
chronic bleeding
68When are crystals present in synovial fluid?
metabolic disorders and decreased renal function
other causes: increased blood levels, degeneration of bone and cartilage, injection of corticosteroids
69What are the (5) crystals found in synovial fluid?
Monosodium urate (MSU), Calcium pyrophosphate dihydrate (CPPD), cholesterol, corticosteroids, and calcium oxalate
70What disease does monosodium urate (MSU) lead to?
gout
71What disease does calcium pyrophosphate dihydrate (CPPD) lead to?
pseudo-gout
72What can lead to MSU in joint?
impaired purine metabolism
high purine foods
leukemia chemotherapy
decreased renal excretion of uric acid
73What can lead to CPPD in joint?
degenerative arthritis
disorders causing elevated calcium levels
74What microscope do you use to view MSU/CPPD?
polarized microscope that directs/filters light parallel in one direction
75Characteristic of MSU crystals in microscope
when light is parallel, YELLOW
when light is perpendicular, BLUE
76Characteristic of CPPD crystals in microscope
when light is parallel, BLUE
when light is perpendicular, YELLOW
77Describe cholesterol crystals in syn fluid
systemic autoimmune disease (LE, RA); nephrotic conditions
appears similar to urine cholesterol crystals : notched corners
78How do corticosteroid injections affect syn fluid?
flat variable plates that show up as steroid molecule artifacts
79When do you see calcium oxalate in syn fluid?
renal dialysis patients
80What are other artifacts that can be found in syn fluid?
starch, powdered anticoagulants, dust, scratches
81What are lupus cells (LE)?
Neutrophils with segmented nucleus pushed to one side of the cell and the rest of cytoplasm is filled with vacuole (leukocyte erythematosus)
82When do you see decreased levels of glucose in syn fluid?
in inflammatory and septic categories
83What things can reduce glucose?
infection or cancer using up glucose
84If glucose decreases, lactate…
increases (due to breakdown of glucose)
85What should the normal glucose level be in syn fluid?
within 10 mg/dL of plasma glucose
86What circumstances would synovial fluid protein increase?
anything where blood mixes with synovial fluid
87Why is gram stain important for syn fluid?
can indicate microorganisms or inflammatory infections quickly, and treatment can start soon
88What is important about diplococci in syn fluid?
Neisseria gonorrhea, which can lead to joint damage
89What are the most common autoimmune causes of arthritis?
Rheumatoid Arthritis (RA) and Lupus erythematosus (LE)
90What organism causes lyme disease and why?
Borrelia burgdorferi (from ticks) that has a propensity for joint cavity
91What are some characteristics of lyme disease?
Joint pain and fatigue