Clinical features

Symptoms

Pain

· usual presentation

· insidious onset with slow worsening

· may be ill-defined or referred

· initially mechanical

· gradually becomes constant

· then night pain develops

Stiffness

· occurs after inactivity

· becomes constant

· morning stiffness not as prominent as RA

Swelling

· intermittent from effusion

· continuous from capsular thickening or osteophytes

Deformity

· from joint instability

Loss of function

· inability to perform daily tasks

Signs

· swelling

· effusion

· capsular / synovial thickening

· osteophytes

· deformity

· muscle wasting

· tenderness

· restricted ROM

· crepitus

· instability

Patterns

Monoarticular or pauciarticular OA

· pain and dysfunction in 1 or 2 of the large wt-bearing joints

· two subgroups

Secondary OA

· OA single joint from previous problem

· most common is knee from meniscectomy

Primary hip OA

· usually young man

· maybe due to mild dysplasia

Polyarticular OA

· usually middle-aged woman

· pain, swelling and stiffness in fingers

· characteristic knobbly appearance of IP jts

· from osteophytes and soft tissue swelling

· Heberden’s nodes in DIP jts

· Bouchard’s nodes in PIP jts

· often affects knees (medial and PF compartments)

· may also affect

· base of thumb

· MTP jt of hallux

· facet jts of lumbar spine

Rapidly destructive OA

· rapidly progressive loss of joint space

· usually affects hip

· may be analgesic arthopathy

investigations

Plain x-ray

· asymmetric narrowing of joint space

· sclerosis of subchondral bone under cartilage loss

· subchondral cysts close to joint surface

· osteophytes at margins of joint

· evidence of previous disorders

Bone scan

· increased activity in subchondral region

· reflects increased vascularity and new bone formation

differential diagnosis

· avascular necrosis

· rheumatoid arthritis

· psoriatic arthritis

· diffuse idiopathic skeletal hyperostosis

treatment

Early

Pain relief

· analgesics

· NSAIDs

· local heat

Rest

· modification of activities

· rest during flares

Physiotherapy

· exercises to

· maintain range

· maintain muscle power

Load reduction

· weight loss

· walking stick

· avoidance of unnecessary stress

Intermediate

· realignment osteotomy

· arthroscopic washout

Late

· arthrodesis

· arthoplasty