Arthritis - OA

Question 1

___ is the most common form of arthritis

Answer 1

OA

1 in 4 people in US

Question 2

Leading cause of disability in older adults:

Answer 2

OA

Question 3

Most commonly affected joints (but can impact ANY synovial joint):

Answer 3

Hips
Knees
Hands

*shoulder, ankle,

Question 4

OA: Clinical Features

Answer 4

Loss of Articular Cartilage
Synovitis
Boney Changes
Ligamentous Changes
Meniscal Changes

Question 5

OA: Patient Impact

Answer 5

Pain
Swelling
Stiffness
Loss of Function

Question 6

Bone responds by laying down more bone:

Answer 6

*osteophyte is one way

*sclerosis is the other way (bright white new layer)

Question 7

Ligamentous changes = what the osteophyte is responding to

Answer 7

ligaments become more lax (take away some of the stretch they are under)

*osteophytic lipping occurs

*LCL and MCL more lax - lipping happens to make deeper bowl

Question 8

OA Pathophysiology

Answer 8

Degenerative process of the whole joint with different phenotypes emerging

Question 9

Primary OA:

Answer 9

Idiopathic

Question 10

Secondary OA:

Answer 10

Underlying cause or event (trauma)

Question 11

Risk factors for primary OA:

Answer 11

Age
Obesity/Metabolic Disease
Sex (60% female)

Question 12

Cartilage Major Components:

Answer 12

Water

Extracellular Matrix (ECM) & Proteoglycans

Chondrocytes (Responsible for both catabolism and anabolism)

Question 13

Cartilage Function:

Answer 13

Withstand highly repetitive compressive and shear loads, maintain a near frictionless joint surface environment, allow force transmission between articulating bones

Question 14

collagen arrangement of articular cartilage:

Answer 14

articular surface

superficial tangetial zone: 10-20%

middle transitional zone: 40-60%

deep zone: 30%

calcified cartilage
subchondral bone
cancellous bone

Question 15

Review of normal cartilage physiology and biomechanics:

Answer 15

Uses hydrodynamics- water flows out in response to compression

Proteoglycans are hydrophilic, attract water to flow back into cartilage following water loss

Combination of hydrodynamics and ECM structure allow compressive forces to be converted to shear at the calcified cartilage/bone interface

Question 16

Cartilage Regeneration:

Answer 16

Chondrocytes repair ECM (very slow process) -> poor healing potential

Chondrocytes are mechanosensitive, regenerative process is stimulated in response to loading

Question 17

What’s happening with OA - Impairment of cartilage regeneration

Answer 17

Regeneration is too slow to keep up with damage repair AND/OR regeneration pathway is altered

Presence of inflammation impacts chondrocyte function

Produce more pro-inflammatory markers and matrix degrading enzymes

Early chondrocyte senescence

Question 18

Proteoglycan loss occurs first, followed by ___

Answer 18

eventual ECM breakdown

Loses ability to handle loads via hydrodynamics (less water), placing more stress on ECM

Question 19

Articular Cartilage Breakdown:

Answer 19

This process is going on for YEARS/DECADES before we can see cartilage breakdown

Translation: By the time we start to see cartilage breakdown its far too late

Question 20

Cartilage response to loading in controls vs OA:

Answer 20

More ECM deformation and more water loss in OA

Question 21

Primary OA Phenotypes:

Answer 21

1) overweight/obesity
*poor diet indirectly impacts

2) ageing

3) lifestyle choices

all 3 lead to inflammaging ->chondrosenescene -> OA

Question 22

Secondary OA:

Answer 22

OA due to associated event

The normal joint structure and biomechanics are impacted resulting in both inflammatory environment and changes to loading environment

Slow cartilage metabolism does not adapt quickly enough to joint changes

Question 23

Joint Injury: PTOA

Answer 23

Knee injury: 6x risk increase

Abnormal Alignment or Geometry (Congenital, tumor, etc)

Malalignment of the knee is an independent risk factor of OA progression

Question 24

___ is an independent risk factor of OA progression

Answer 24

Malalignment of the knee

Question 25

PTOA: The major issue:

Answer 25

Huge cohort of young individuals with old knees Lots of years left in the medical system Downstream healthcare impacts of physical inactivity and/or disability Joint arthroplasty only lasts~ 20 yrs * These people may need multiple arthroplasties in their lifetime = $$$$$

Question 26

post ACL: ~50% will have radiographic OA within ___

Answer 26

10-20 yrs

Question 27

Much more complex than originally thought (not just wear and tear)

Answer 27

Cartilage regeneration is unable to keep up with microdamage Impacted by biomechanics and/or inflammatory environment Impacts the whole joint (not just articular cartilage)

Question 28

We don’t fully understand what causes symptoms - OA Pathophysiology

Answer 28

Worse radiographic OA more likely to have symptoms

Question 29

Primary OA: Intersection between ____

Answer 29

aging, genetics, metabolic syndrome/obesity, lifestyle choices

Question 30

Secondary OA: Intersection between _____

Answer 30

joint biomechanics and inflammation

Question 31

Common Imaging Features:

Answer 31

Loss of joint space width Osteophyte formation Sclerosis of subchondral bone

Question 32

Imaging Modality:

Answer 32

Radiographs (gold std) MRI CT

Question 33

OA Grading System:

Answer 33

0-4

Question 34

OA: grade 0

Answer 34

no OA no osteophytes no JSN

Question 35

OA: grade 1

Answer 35

doubtful OA possible osteophytes doubtful JSN

Question 36

OA: grade 2

Answer 36

mild OA definite osteophytes possible JSN

Question 37

OA: grade 3

Answer 37

moderate OA moderate osteophytes definite JSN

Question 38

OA: grade 4

Answer 38

severe OA large osteophytes great JSN

Question 39

Curveball:

Answer 39

Up to 50% of people with radiographic OA have no associated symptoms We do not currently understand why some are symptomatic and others are asymptomatic

Question 40

Advanced Imaging Techniques:

Answer 40

New promising imaging sequences that allow us to assess cartilage physiology before cartilage damage is evident MRI T1rho MRI T2*

Question 41

MRI T1rho:

Answer 41

Associated proteoglycan content/concentration

Question 42

MRI T2*:

Answer 42

Associated with ECM orientation and free vs bound water

Question 43

We currently have ___ treatments that have been proven effective at reversing OA or stopping its progression

Answer 43

zero

Question 44

The treatments we do have:

Answer 44

Treat the symptoms (reduce pain) Promote function Prevent OA from happening in the first place

Question 45

Prevent OA from happening in the first place:

Answer 45

Injury prevention (Secondary OA) Lifestyle (Primary OA) * Moderate Activity * Weight Management

Question 46

Pharm interventions:

Answer 46

NSAIDs Corticosteroids Hyaluronic Acid Biologics

Question 47

Surgery interventions:

Answer 47

Debridement Cartilage Repair Joint Replacement

Question 48

Common NSAIDs:

Answer 48

Ibuprofen Naproxen Diclofenac

Question 49

NSAIDs Treatment:

Answer 49

Effective at reducing pain and targeting synovitis Cheap Cons: Some with comorbidities unable to use Some have topical versions available Con: Treats symptoms, no impact on disease

Question 50

Common Corticosteroids:

Answer 50

Cortisone Injection

Question 51

Corticosteroid Treatment:

Answer 51

Effective at reducing short-term pain and inflammation Intended to be an adjunct More localized treatment Cons: Some with comorbidities unable to use Con: Treats symptoms, no impact on disease Con: Limited dosage schedule, infection risk

Question 52

Hyaluronic Acid Common: (Viscosupplementation)

Answer 52

Synvisc Hyalgen Euflexxa

Question 53

Hyaluronic Acid Treatment:

Answer 53

Can improve symptoms and function in mild/moderate OA (high bias evidence) “lubricates” the joint Cons: Expensive (limited insurance coverage) Con: Treats symptoms, no impact on disease Con: Limited dosage schedule

Question 54

Common Biologics:

Answer 54

Stem Cell Therapy Platelet Rich Plasma (PRP)

Question 55

Biologics treatment:

Answer 55

Promising basic science results Some mixed results but mostly poor findings of effectiveness in vivo No Standardization Cons: Expensive (not covered by insurance) Cons: Travel to special clinic

Question 56

Disease-Modifying Osteoarthritis Drugs (DMOADs)

Answer 56

Corticosteroids have short-term symptomatic benefits and should be adjuncts Placebo effect from injections

Question 57

Surgery:

Answer 57

Joint replacement is highly effective but still considered a salvage procedure Reduces pain, reduces disability, improves QOL

Question 57

Viscosupplementation studies that show benefit have ___

Answer 57

high risk of bias Recommendation: try it if the patient had little to no effect from steroid or can’t have steroid

Question 58

Rehab Interventions:

Answer 58

Weight Management Exercise Bracing

Question 59

Weight Management:

Answer 59

9-76% reduction in pain following gastric bypass Pain scores reduced, functional scores improve Improved joint space associated with weight loss Con: Poor adherence to interventions Dose response exists (More weight loss more symptomatic improvement)

Question 60

Physical Activity and OA:

Answer 60

Maintain and/or improve functional capacity Supplement diet for weight loss No specific recommendations: *No evidence to support a hierarchy of types of exercise *Whatever the patient likes to do will improve adherence

Question 61

Rehab programs:

Answer 61

Decrease pain, improve function, improve QOL Quad strength/power = Function PT had better outcomes through 1 year follow up vs corticosteroid injection

Question 62

Bracing:

Answer 62

Unloader braces have some symptomatic benefit Other braces: Likely placebo/tactile Braces are generally bulky, uncomfortable, and/or not aesthetically pleasing

Question 63

In general, running was not associated with OA

Answer 63

Running at a recreational level was associated with
lower odds of hip/knee OA compared to those 
running competitively and more sedentary,
non running individuals Recreational runners have the lowest incidence of OA

Question 64

The Debate:

Answer 64

Don’t Unnecessarily Load Don’t Change Activity swinging pendulum

Question 65

Not all OA is the same:

Answer 65

Primary vs secondary with phenotypes of each It is unlikely there will be one blanket recommendation, each subset will need its own specific recommendations that is also adjusted to the individual patient

Question 66

The most basic principle of treatment is the ___

Answer 66

risk reward benefit to the patient

Question 67

Promote physical activity for weight management, joint health maintenance, pain/mental health

Answer 67

Weigh the risk reward for whether higher loading activity is appropriate Use irritability as a guide

Question 68

Quad strength and power to maintain function

Answer 68

Combination of open and closed chain depending on joint irritability and compensations

Question 69

OA PT Management

Answer 69

Assistive device use for significant gait deviations Self-management focus Booster visits currently being explored, watch for evidence

Question 70

The future:

Answer 70

Harness mechanosensitivity of chondrocytes to promote regeneration Can we identify specific loading inputs to optimize cartilage health after injury and surgery Likely in combination with pharm Use of biologics to regenerate damaged cartilage

Question 71

Our current post-injury and post-op treatments are focused on short term goals of ___ and have little focus on ___

Answer 71

return to sport and function long-term joint health