Osteoarthritis Flashcards
If someone has joint disease and is Rh-positive does this seal the diagnosis for RA?
NO, many people, especially older people, are Rh+. You need to look at the joints involved
What are some risk factors for developing Osteoarthritis?
- Age
- Joint Location
- Obesity
- Genetic Predisposition
- Joint Malalignment
- Trauma
- Gender
What morphological changes are seen in early osteoarthritis?
- Irregularity in the surface of Articular Cartilage
- Superficial Clefts within the Tissue
- Altered Proteoglycan Distribution
What morphological changes are seen in late osteoarthritis?
- Deepened Clefts
- Increased Surface Irregularities
- Articular Cartilage Ulceration
- Exposure of Underlying bone
- Osteophyte Formation
What inflammatory mediators are responsible for the small amount of inflammation seen in osteoarthritis?
- IL-1ß
- TNF
What major catabolic factor is produced by chrondrocytes in response to proinflammatory cytokines?
Nitric Oxide is produced by NO synthase in chondrocytes in response to inflammation
Nitric Oxide Synthase is upregulated in chondrocytes in response to inflammation, but there is also a proinflammatory enzyme upregulated in chondrocytes in osteoarthritis. Name this enzyme.
COX-2 is upregulated in Osteoarthritis
What joints are most typically affected by osteoarthritis?
Hands, Hips, Knees, Spine, and Feet are the joints most affected by osteoarthritis
T or F: individuals with Osteoarthritis have the same mortality rate as others in the population.
False, people with osteoarthritis have increased mortality rates
Explain the general process that leads to degeration of cartilage and pain in osteoarthritis.
1Mechanical Forces induce altered metabolic state and release of Plasminogen activator and Matrix Metalloproteases from tissue. 2Collagen breakdown products tell the synovium that damage has occurred. 3IL-1, NO, PGE2, and TNF are released from the synovium and act to induce release of inflammatory cytokines by chondrocytes. 4COX-2 and Nitric Oxide Synthase are two enzymes induced by this process causing release of PGE2 (mediating pain) and NO that perpetuates the degerative process. 5Meanwhile IL-1, NO, and Aggrecanases may also be released by chondrocytes in response to mechanical stress.
How does the process of osteoarthritis come about?
Both genetic and environemental factors may initiate the disease via altered metabolism in bone and cartilage causing structural damage, inflammation, and pain that may result in loss of joint function.
**Notice that this process may be self perpetuating with regard inflammation.
What is the general 3 step progression in the formation of osteoarthritis?
- Progressive Cartilage Loss
- Subchondral Thickening
- Marginal Osteophytes
What are symptoms commonly associated with osteoarthritis?
The patient may complain that 1using their joints leads to increased pain and that the 2pain increases throughout the day. Importantly, they are 3unlikely to complain of gelling of joints after sitting for prolonged periods.
What are some important signs of Osteoarthritis?
- Decreased Range of Motion
- Increased Joint instability
- Bony Enlargement
- Restricted movement
- Crepitus (indicative of cartilage damage)
- some swelling is possible
What combination of risk factors would put you at the highest risk of getting osteoarthritis?
Being a 1old 2diabetic and sexually active 3fat 4female whose 5parents had OA that had experienced 4previous joint trauma with a long history of 5metabolic disorders.
**Important Notes***
- 75% of people over 70 have OA
- Heredics play an important role
- Neuromuscular dysfunction which may result from many diseases is an important risk factor
What lab test is diagnostic or heavy associated with Osteoarthritis?
No specific lab tests can rule this disease in but a normal sedimentation rate, and CRP, with cartilage degradation pdts. in synovial fluid helps to rule out RA and increases likelihood that its OA.
In what joints are you most likely to see PRIMARY osteoarthritis?
• what is the difference in primary and secondar?
PRIMARY most often involves the spine (excluding thoracic region), Hips, Knees, PIPs, DIPs, and MIP of the thumb and Big Toe.
**Secondary OA is unpredicatible becuase it often corresponds to joint overuse that may be related to occupation**
What key radiographic features should you look for in Osteoarthritis?
• is this information useful for making a diagnosis?
- Joint Space Narrowing
- Marginal Osteophytes
- Subchondral Cysts
- Bony Sclerosis
- Malalignment
**YES, the above characteristics “NAIL THE DIAGNOSIS”**
What key features of this hand differentiate it from someone with RA?
This X-ray is indicative of Osteoarthritis because the DIPs are heavily involved (this is a feature of OA, NOT RA). Additionally, the ulnar styloid process is maintained.
What is the most common spot in the hand to be affected by Osteoarthritis?
Carpometacarpal Joint at the THUMB are the most common location to be affected in the hand and may cause significant loss of function.
Below you see hyperdense, ridges edges without a joint space indicating OA.
What key findings are shown here?
• what kind of pain will this patient feel?
Osteophytes (superior acetabulum) and Subchondral Sclerosis, whith COMPLETE LOSS OF JOINT SPACE
**These changes will cause severe hip pain located in the GROIN**
Groin is where real hip pain presents
If you see osteoarthritis in the ankle what do you suspect the general etiology is?
• what should you do if you see OA here?
The Ankle is NOT a typical place for OA to present so you need to:
• Ask about previous trauma and/or overuse
• Neuromuscular Disease (DIABETIC NEUROPATHIES)
• Metabolic disorders (Caclcium Pyrophosphate Deposition Disease)
Where does osteoarthritis often present in patients with Diabetic Neuropathy?
• How do these differ from the norm?
- MTPs 2-5 are often involved in addition to the 1st MTP bilaterally (note that MTPs 2-5 typically are not involved in primary OA). Additionally, the midfoot is commonly involved
- Changes seen in x-ray are far more destructive than those seen in primary OA
What distinct feature on the X-ray of a hand may help you to differentiate true osteoarthritis from calcium pyrophosphate disease?
Degeneration of the ulnar styloid does NOT happen in OA but is seen in CPPD (pseudogout) as shown below. Additionally, you see joint space narrowing at the MIPs which may help to differentiate this disease from RA.
What is shown here on the left and right?
Left is normal articular cartilage on the right you can see Fibrillation of articular cartilage and colonies (clones) of regenerating cells
Does eburnation happen in early or advanced stages of OA?
Eburnation occurs in later stages of OA.
What is shown here?
• Fibrous-lined “cysts” under the exposed subchondral bone in advanced osteoarthritis
What is this?
What stage of OA is this histology representative of?
Histology shown here indicates fissuring and pits that occurs in articular cartilage during EARLY stages of OA
Notice the exposed bone in the picture on the left
