OA

Question 1

epidemiology of OA

Answer 1

The prevalence of OA increases with age, and most people over 60 years will have some radiological evidence of it although only a proportion of these have symptoms.
It is more common in women and there is a familial tendency to develop nodal and generalized OA.

Other risk factors are obesity, a fracture through a joint, congenital joint dysplasias (DDH), pre-existing joint damage of any cause, occupation (e.g. OA of the hip in farmers and labourers) and repetitive use and injury associated with some sports. “Tear, flare and repair”.

SO BASICALLY RF’S= AGE, OBESITY, DDH, OCCUPATION, SPORTS.

Question 2

pathology

Answer 2

progressive destruction and loss of articular cartilage With accompanying periarticular bone response.
The exposed subchondral bone becomes sclerotic, with increased vascularity and cyst formation.
Attempts at repair produce cartilaginous growths at the margins of the joint which later become calcified (osteophytes). there is synovial hypertrophy, subchondral changes, joint effusion.

Question 3

pathogenesis

Answer 3

just know it involves:
metalloproteins, IL-1, TNF-alpha - these inhibit collagen production,
there is also deficiency of growth factors, OPG activation RANKL,
it can also be genetic (mutations in collagen type2)

Question 4

Clinical features

Answer 4

joint pain made worse by movedment and relieved by rest,
morning stiffness less than 30mins,
mostly DIPJ’s and first carpometacarpal joint of the hands,
first metatarsophalangeal joint of the foot and the weight-bearing joints – vertebrae, hips and knees.

On examination - deformity and bony enlargement of the joints, limited joint movement and muscle wasting of surrounding muscle groups.
Crepitus (grating) due to the disruption of the normally smooth articulating surfaces of the joints.
There may be a joint effusion.
Heberden’s nodes are bony swellings at the DIPJs.
Bouchard’s nodes are similar but occur at the proximal interphalangeal joints (PIPJs).

overall: PAIN ON MOVEMENT, DIPJ’s, WEIGHT BEARING JOINTS, ENLARGEMENT, DEFORMITIES, LIMITED MOVEMENT, CREPITUS, MUSCLE WASTING, JOINT EFFUSION, HEBERDENS, BOUCHARDS.

Question 5

DDX

Answer 5

gout, septic arthritis, malignancy, psoratic Arthritis

Question 6

Ix

Answer 6

xray (also examine at image the joint above and below)

Question 7

ABSOLUTELY CLASSIC QUESTION - what is seen on xray OF OA?

Answer 7

L – Loss of Joint Space
O – Osteophytes
S – Subarticular Sclerosis (increased density of the bone along the joint line)
S – Subchondral Cysts (fluid filled holes in the bone, aka geodes)

Question 8

holistic assessment to self-management

Answer 8

social, occupational, mood, sleep, support network, exercise attitudes, any comorbidities, pain assessment.

Question 9

Non-pharmacological Tx

Answer 9

thermotherapy, electrotherapy, aids, manual therapy, Local strengthening and aerobic exercises improve local muscle strength, improve the mobility of weight-bearing joints and improve general aerobic fitness. Bracing devices, joint supports, insoles for joint instability and footwear, A walking stick.
WALKING STICK/ PHYSIO/ WEIGHT LOSS/ DIET ADVICE

Question 10

Pharmacological Tx

Answer 10

NSAID's (topical or oral)
Capsaicin, 
(can also use Paracetamol)
Intra-articular injections - hyaluronic acid. 
Analgesia too.

Question 11

when to refer for surgical replacement?

Answer 11

quality of life impact. - do a surgical arthroplasty