This document summarizes osteoarthritis of the knee. It describes OA as a degenerative joint disease characterized by loss of cartilage and bone changes. Risk factors include age, obesity, joint injury, and genetics. Symptoms include pain and stiffness that worsen with use. Diagnosis is based on symptoms and x-rays showing cartilage loss, bone spurs, and bone changes. Treatment focuses on reducing pain and inflammation, maintaining joint motion, and may include medications, injections, exercise, or surgery like knee replacement for severe cases.

1. Osteoarthritis O
Knee

2. OA KNEE
• Chronic, Non inflammatory, degenerative
disease.
• characterised by loss of articular cartilage
and periarticular bone remodelling,
particularly large weight-bearing joints
• Common in older patients but can occur in
younger patients ( genetic mechanism ,
previous joint trauma )

3. Pathophysiology
• Degenerative alterations primarily begin in the
articular cartilage
• External forces accelerate the catabolic effects of the
chondrocytes and disrupt the cartilaginous matrix
• Enzymatic destruction increases cartilage
degradation ↓ proteoglycans and collagen
synthesis
• Decreased strength of the cartilage is compounded
by adverse alterations of the collagen
• Reduced contact area of the cartilage

4. Pathophysiology
• Loss of cartilage results in the loss of the joint
space
• Progressive erosion of the damaged cartilage
occurs until the underlying bone is exposed
• Subchondral bone responds with vascular
invasion and increased cellularity, at areas of
pressure

5. Pathophysiology
• The traumatized subchondral bone may
undergo cystic degeneration
• At nonpressure areas along the articular
margin → irregular outgrowth of new bone
(osteophytes)

7. • Normal joint
• hinge joint formed

8. • Surface layer of cartilage
break down and wears
away,causes the bones
under the cartilage to rub
together
• Pain, swelling, and loss of
motion result
• formation of bone spurs

9. Incidence
• Incidence increases with age
• USA approximately 80-90% of individuals
older than 65 years have evidence of primary
osteoarthritis
• After age 55 years, the prevalence increases in
women in comparison with men

10. Incidence
• Equivalent prevalence occurs in men and
women aged 45-55 years (↑dramatically after
the age of 50 years)
• Most adults older than 55 years show
radiographic evidence of osteoarthritis
• No significant correlation exists between
incidence of OA and race

11. Causes
Primary OA
• Idiopathic
• Defective gene

12. Causes
Secondary OA
– Obesity
– Repetitive use (ie, jobs requiring heavy labor and
bending)
– Previous trauma (ie, posttraumatic OA)
– Infection

13. Causes
– Crystal deposition
– Acromegaly
– Previous rheumatoid arthritis (ie, burnt-out
rheumatoid arthritis)
– Heritable metabolic causes (eg, alkaptonuria,
hemochromatosis, Wilson disease)

14. Causes
– Hemoglobinopathies (eg, sickle cell disease,
thalassemia)
– Underlying orthopedic disorders (eg, congenital
hip dislocation, slipped femoral capital epiphysis)
– Disorders of bone (eg, Paget disease, avascular
necrosis)

15. History
• Insidious throbbing arthralgias with activity
• Initially, resting relieves the pain
• Eventually, the pain occurs even at rest
• Morning stiffness ≥ 30 minutes
• Intermittent joint swelling

16. Symptoms
• Pain
• Stiffness
• Gelling
• Instability

17. Signs
• Pain
• Tenderness
• Swelling
• Effusion
• Crepitus
• Limitation of movement and muscle wasting

18. Physical
• Early
– Joints may appear normal
– Gait may be antalgic if weight-bearing joints are
involved

19. Physical
• Later
– Visible osteophytes may be noted
– Joints may be warm to palpation
– Palpable osteophytes frequently are noted
– Joint effusion frequently is evidenced in
superficial joints

20. Physical
– Range-of-motion limitations, because of bony
restrictions and/or soft tissue contractures, are
characteristic
– Crepitus with range of motion is not uncommon

21. classification
1. Ahlbäck classification system
2. Kellgren and Lawrence system

22. 1. Ahlbäck classification system
• This classification was proposed by Ahlback et al in
1968.
• grade 1: joint space narrowing (less than 3 mm)
• grade 2: joint space obliteration
• grade 3: minor bone attrition (0-5 mm)
• grade 4: moderate bone attrition (5-10 mm)
• grade 5: severe bone attrition (more than 10 mm)

23. 2. Kellgren and Lawrence system
• This classification was proposed by Kellgren et al. in 1957 2
and later accepted by WHO in 1961.
• grade 0: no radiographic features of OA are present
• grade 1: doubtful joint space narrowing (JSN) and possible
osteophytic lipping
• grade 2: definite osteophytes and possible JSN on
anteroposterior weight-bearing radiograph
• grade 3: multiple osteophytes, definite JSN, sclerosis, possible
bony deformity
• grade 4: large osteophytes, marked JSN, severe sclerosis and
definite bony deformity

24. Imaging
• Plain radiographs
• Bone scans may be helpful in early diagnosis
of OA of the hand

25. • The space between the
bones of the upper and
lower leg is smaller
• Bony spurs
(osteophytes)
• Increase bone density
at the margin of the
joint

26. x-ray findings
–Joint space narrowing
–Osteophytes
–Subchondral sclerosis : ↑ bone density,
frequently found adjacent to joint space
–Subchondral cysts : fluid-filled sacs which
extrude from the joint

27. Diagnosis
• On the basis of the initial history and
examination
• X-rays

28. PROGRESS
• Osteoarthritis begins when the joint
cartilage starts to become worn down →
decreases the ability of the cartilage to
work as a shock-absorber to reduce the
impact of stress on the joints
• The remaining cartilage wears down
faster→ bones to grind against one
another
• Bone spurs may form

29. Treatment

30. Goals of managing OA
• Controlling pain
• Maintaining and improving the range of
movement and stability of affected joints
• Limiting functional impairment

31. Treatment
• Education and behavioural intervention
- Aim is to provide patients with an
understanding of the disease process, its
prognosis and the rationale and implications
of managing their condition
• Weight loss
- Weight loss (< 5 kg) has significant short-term
and long-term reduction in symptoms of OA

32. Treatment
• Mechanical aids
- Wear shock-absorbing footwear with good
mediolateral support, adequate arch support and
calcaneal cushion
• Exercise
• Aim of exercise is to reduce pain and disability by
strengthening muscle, improving joint stability,
increasing the range of movement and improving
aerobic fitness

34. Treatment
• Medication
- Acetaminophen (Tylenol®) is a mild pain
reliever with few side effects
• Anti-inflammatory medication, such as
ibuprofen and aspirin
• COX-2 inhibitors
• Glucosamine and Chondroitin sulfate

35. Treatment
• Intra-articular injection
- Glucocorticoids injection
- Hyaluronic Acid (HA) and similar
hyaluronan preparations (eg, Synvisc)

36. Treatment
• Surgery
• Arthroscopy (including debridement,and
lavage/irrigation)
• Proximal Tibial Osteotomy
• Artificial Knee Replacement
• Osteotomy
• Arthroplasty or Joint Replacement