Osteoarthritis

Question 1

What is osteoarthritis?

Answer 1

A disorder of synovial joints which occurs when damage triggers repair processes leading to structural changes within a joint

Question 2

What causes OA joint damage?

Answer 2

repetitive excessive loading/stress of the joint or injury.

Question 3

Which joints does OA affect?

Answer 3

Affects synovial joints such as knees, hips, hands and often affects them bilaterally

Question 4

How does OA occur?

Answer 4

by active dynamic alteration of the structure of a joint over time due to imbalance between the repair and destruction of tissues

Question 5

Causes of OA

Answer 5

Causes are complex and multifactorial with primary and secondary causes.
There are genetic, biological and biomechanical aspects.

Question 6

Primary causes of OA

Answer 6

• Occurs in older age
• Mostly in weight bearing joints (hips and knees)
• Also common in 1st carpometacarpal joint and distal interphalangeal joints of the finger
• no apparent cause

Question 7

Causes of secondary OA

Answer 7

• Consequence of abnormal force across joint (post-trauma, deformity)
• Abnormal articular cartilage from disease or infection etc.

Question 8

Risk factors of OA

Answer 8

• Age
• Obesity
• Genetics
• Heavy work
• High impact sports
• Trauma/injury
• Hip deformities or dysplasia
• Knee malalignment

Question 9

What structural changes occur to cartilage from OA

Answer 9

• softening (due to higher water content)
• fibrillation (tearing or fraying)
• fissuring (cracks that can deepen over time)
• reduced thickness
• erosion
• exposure of subchondral bone.

Question 10

What structural changes occur to subchondral bone from OA

Answer 10

• Exposure of bone results in sclerosis (area of increased density and thickness). This is known as eburnation.
• Reactive remodelling of bone results in the formation of osteophytes at the joint margins.
• Bone volume increases leading to joint space narrowing.
• In later stages, development of bone marrow lesions and bone cysts.

Question 11

Symptoms of OA

Answer 11

pain, brief morning stiffness, functional limitations

Question 12

What is found on physical examination of OA?

Answer 12

restricted or painful movements, crepitus (grinding sound within joint as it moves), joint tenderness and bony enlargement.

Question 13

Kellgren-Lawrence classification of OA

Answer 13

• Grade 1- Doubtful narrowing of joint space with possible osteophyte formation
• Grade 2- possible narrowing of joint space with definite osteophyte formation
• Grade 3- Definite narrowing of joint space with moderate osteophyte formation, some sclerosis and possible deformity of bony ends
• Grade 4- Large osteophyte formation, severe narrowing of joint space with marked sclerosis and definite deformity of bony ends

Question 14

Physiotherapy treatment goals of OA

Answer 14

• Increase strength
• Increase mobility
• Increase ROM
• Reduce pain
• Optimise function

Question 15

OA outcome measures

Answer 15

• Visual analogue scale/ NRS
• Western Ontario and McMaster universities OA index (WOMAC)
• Hip disability and OA outcome scores (HDOAOS)