Noninflammatory Joint Pathologies Flashcards
What is joint degeneration?
A disease in which the function or structure of the affected tissues or organs changes for worse over time
Joint degeneration is driven by ___
the mechanical wear of joints
Joint degeneration is characterized by ___
progressive destruction of articular cartilage at synovial joints
Is joint degeneration inflammatory?
No
What is the most common joint problem in humans?
Joint degeneration
Primary joint degeneration is an ___-related pathology
age
What genetic mutation related to cartilage may cause joint degeneration?
Mutations in type II collagen gene (COL2A1)
___% of 75-79 years of age are affected by joint degeneration
85%
Before age 45, joint degeneration is more common in ___
men
After age 55, joint degeneration is more common in ___
women
What is secondary joint degeneration?
Due to an underlying cause
What are some etiologic factors of joint degeneration?
- Increased unit load
- Disruption of water bonding (decreased resilience)
- Subchondral stiffening
- Biochemical changes
Which biochemical changes are etiologic factors for joint degeneration?
- Decreased proteoglycans
- Glycosaminoglycan chain length reduced
- Increased fibrillin
- Increased water binding
- Collagenase present
How does bone respond to early joint degeneration?
Reparative response
With joint degeneration, ___ and ___ will progressively decrease
matrix synthesis and cellular replication
When during joint degeneration might you see reactive inflammation?
Later disease
With reactive inflammation later in joint degeneration, local increases in ___ and ___ induce an increase in nitric oxide and PGE2
IL-1b and TNF-a
With reactive inflammation later in joint degeneration, local increases in IL-1b and TNF-a induce an increase in ___ and ___
nitric oxide and PGE2
The beginning of joint degeneration pathogenesis involves a decrease in ___ leading to ___
decrease in proteoglycan synthesis leading to chondrocyte death increasing
In the pathogenesis of joint degeneration, what is the result of decreased proteoglycan synthesis and increased chondrocyte death?
Fibrillation or cracking in the surface layers of the articular cartilage
In the pathogenesis of joint degeneration, what are the immediate consequences of fibrillation propagation?
- Synovial fluid fills defects, increasing fissuring
- Pieces of cartilage may break off
In the pathogenesis of joint degeneration, fibrillation propagation may eventually crack across the tide mark.
What are the histological events that occur at this point?
- Neovascularization/angiogenesis
- Osteoclast activity increases (subchondral resorption)
- Osteoblastic activity increases (subchondral sclerosing)
- Fibrocartilage forms
In the pathogenesis of joint degeneration, fibrocartilage forms to fill cracks across the tide mark.
What happens if that fibrocartilage plug breaks down?
- Exposes subchondral bone to mechanical erosion
- Eburnation
- Subchondral sclerosing
In the pathogenesis of joint degeneration, the fibrocartilage plug made to fill cracks can break down and become eburnated bone.
What if eburnated bone cracks?
- Cracks fill with synovial fluid
- Subchondral cysts form and may increase in size
What are three consequences of haphazard remodeling associated with joint degeneration?
- Osteophytes (bone spurs)
- Subchondral sclerosis (joint stiffening, increased bone mass)
- Subchondral bone cysts
With joint degeneration, where are osteophytes most likely to develop?
Joint margins
Which joints are capable of degenerating?
Any and all
Which joints most commonly degenerate?
Hands, knees, hips, cervical and lumbar spine
How do degenerated joints appear externally?
May be enlarged (and tender)
How does joint degeneration feel upon palpation?
May have crepitus
What are Heberden nodes?
Nodes at distal interphalangeal joint seen in joint degeneration of hands
What are Bouchard nodes?
Nodes at proximal interphalangeal joint seen in joint degeneration of hands
With joint degeneration, a patient might have ___ pain following ___ and relieved by ___
patient might have deep achy pain following activity and relieved by rest
When joint degeneration comes with pain, this is generally a sign of ___
significant joint destruction
What are some clinical manifestations of joint degeneration?
- Deep achy pain following activity and relieved by rest
- Short term stiffness in the morning or after inactivity
- Functional limitations in affected joints
What are some functional limitations in joints affected by degeneration?
- Intra-articular loose bodies
- Large osteophytes
- Loss of congruity in joint surfaces
- Muscle contractures or decreased muscle mass
What are six radiographic findings in joint degeneration?
- Non-uniform loss of joint space
- Subchondral sclerosis
- Osteophyte formation
- Subchondral cysts
- Chondral/osteochondral loose bodies (joint mice)
- Subluxation
Disc degeneration is also known as ___
degenerative disc disease, discogenic spondylosis
What are two tissue based pathologies of disc degeneration?
- Spondylosis deformans
- Intervertebral osteochondrosis
Spondylosis deformans involves ___ degeneration of the disc
annular
Intervertebral osteochondrosis involves ___ degeneration of the disc
nuclear
How much disc space is lost with spondylosis deformans?
Minimal loss
How much disc space is lost with intervertebral osteochondrosis?
Prominent loss
How many osteophytes are expected in spondylosis deformans?
Prominent osteophytes
How many osteophytes are expected in intervertebral osteochondrosis?
Minimal osteophytes