Osteoarthritis

Chronic disorder Degenerative joint disease result in progressive erosion

of articular cartilage

Epidemiology

Starts at 50 years of age Female > male (2: 1) 10% of general population

*OA increases in frequency with age. Not because of ageing but OA takes many years to develop.

Classification

Primary OA – idiopathic and appear insidiously arises without obvious predisposing

influences ( majority of cases) Oligo-articular

AgeGenetic – familial tendency

Obesity – OA knee

Secondary OA – presence of other predisposing factor Previous trauma and mechanical problem –

intrarticular # (stepping >1cm),recurrent dislocation

Infection – septic arthritis Congenital deformity of a joint- Perthe’s ds,

SUFE Inflammatory – RA Underlying systemic diseases

DM, Haemochromatosis, Obesity Knees & hands in women, Hips in men

Pathology

The cardinal features are: Progressive loss of cartilage thickness Subarticular cyst formation and sclerosis Remodelling of the bone ends and

osteophyte formation Synovial irritation Capsular fibrosis

Pathogenesis

the normal homeostasis in the joint is disturbed

OA is a disease of wear-&-tear based on: Occur in old age Weight bearing joints Increase frequency in the joints predisposed to

abnormal mechanical stress obese & previous joint deformity

Genetic factors Risk increased with:

Reduced Bone density High levels of oestrogen

Characterized by significant changes of: Composition Mechanical properties of cartilage

Early the degenerating cartilage Increased in water Decreased concentration of proteoglycans Weakening of collagen network (reduce type II

collagen) IL-1, TNF and NO are increased in the joint Increased apoptosis of chondrocytes

These resulted in: Reduce tensile strength Reduce resilience DEGENERATION

Morphology Early stage:

Increased in chondrocytes

Subsequently cracking of the matrix

Gross Granular surface Small fractures &

dislodge , producing ‘joint mice’

Osteophytes formation

Clinical features

Pain Stiffness Swelling Deformities Joint instability Loss of function

History

Age – 50++, obese? Occupation – what type? Any history of trauma that involve joint? Rule out secondary causes – cong, RA Any joint pain? – become worst by activity, relieve by rest(usually patient complaint cannot walk long distance, stand

for long) Joint stiffness – early morning, long rest Noticed swelling? Ask daily activity affected or not??- Climbing stairs- How do they pray?- House works – cooking, laundry

Physical examination

1. General examination Elderly, obese lady2. Inspection• Antalgic gait• Varus deformity• Muscle wasting over the quadriceps• Joint is swollen• No redness or discoloured 3. Palpation Min/no joint effusion (patella tap) Check for tenderness Synovial membrane not thickened Protuberant (osteophyte) at the edge of articular cartilage

4. Movement Limited (reduced ROM) Crepitus on movement5. Special test Valgus and varus stress test

Clinical course

Insidious onset Deep, achy pain that

worsen with use Morning stiffness Crepitus Limited ROM Impingement on

spinal foramina by osteophytes radicular pain, muscle spasm & atrophy

Typically, only one or a few joints

Joint involved: Hips Knees Lower lumbar & cervical Proximal & distal IP

joints First carpometacarpal First metatarsal

Heberden nodes: In women, not in

men Prominent

osteophytes at the distal IP joints

No satisfactory means of preventing primary OA

Permanent disability

Investigation

X – ray features: Narrowing or loss of joint space (1st sign of OA)

reflects loss of articular cartilage; main pathology Osteophyte formation-around the periphery of

the joint Subchondral sclerosis-looks very white on the

radiograph Subchondral cyst

Treatment of osteoarthritis can be divided into 2: Conservative management Operative management

indicated for patients with persistent symptoms

TREATMENTTry to treat patient conservatively, if failed-surgical

1. CONSERVATIV

E

Relieve pain– Analgesic and

NSAIDS- Intra articular corticosteroid- Rest period

and modification of

activity

To increase movement to

prevent ms wasting and

deformity/contracture-

physiotherapy/exercise

programme,non -weight bearing

exercise to strengthen ms

strength (cycling.swimming)

To reduce load on the joint

-Weight loss if patient is obese- Use of walking

stick to distribute the load- avoid

unnecessary stress,eg

jogging,climbing stairs

2.OPERATIVE MANAGEMENT

Arthroscopic debridement and

cleaning of the joint cavity and infusion

of synthetic synovial fluid

Realignment osteotomy- for

unicompartmental OA, to redistribute

the loading forcetowards less damaged parts of

the jt

Arthrodesis-If stiffness is

acceptable and neighbouring joints are not likely to be

prejudiced- Usually done in

young patient

Arthroplasty-Joint replacement- Usually done in

old patient