Knee OA Flashcards
Subchondral
role of shock absorption
Providing nutrients to the cartilage
superficial zone in articular cartilage
protect against shear
middle zone in articular cartilage
some resistance against compression forces
deep zone of articular cartilage
protect against compressive forces
collagen fibers arrange perpendicular to articular surface
act as shock absorbers
calcified Cartilage
In maintaining homeostasis between articular cartilage and the subchondral bone
transport minerals from subchondral bone to the articular cartilage
changes with OA
Subchondral bone remodeling, sclerosis and cyst formation
Angio and neurogenesis- infiltration of nerves and vascularature= pain and weakness
synovial changes- harden and thicken
osteophyte Formation - bone spurs
Bone marrow lesions and osteonecrosis
what structure is not a pain generator
Cartilage
KL classification grade 1
Minute osteophyte
doubtful significance
KL grade 2
Mild
Definite osteophyte
Normal joint space
KL grade 3
Moderate joint
space reduction
KL grade 4
Joint space greatly reduced
Subchondral sclerosis
ACR criteria for OA
Knee pain +3 of the following
Greater than 50 years of age
Less than 30 minutes of morning stiffness
Crepitus with active motion
Bone tenderness
Bony enlargement
No palpable warmth of synovium
ACR for OA with x-rays
knee pain plus one of the following
Greater than 50 years of age
Less than 30 minutes morning stiffness
Crepitus with active range of motion and osteophytes
Modifiable risk factors for OA
obesity
Genu varum/ valgum
Prior injuries (instability or meniscus )
leg Length discrepancies
psychosocial factors
Occupation (squatting, kneeling, lifting)
Vigorous sports or activities
patient symptoms of OA
gradual onset of knee pain, stiffness, and crepitus
worse with inactivity
better with rest
worse with prolonged activities like squatting or stairs
progressively worsens overtime
Swelling
Bony enlargement
varying ROM, strength, flexibility
