Osteoarthritis Flashcards
Definition of Osteoarthritis
Osteoarthritis (OA) is a disabling joint disease characterized by a noninflammatory degeneration of the joint complex (articular cartilage, subchondral bone, and synovium) that occurs with old age or from overuse. It mainly affects the weight-bearing and high-use joints, such as the hip, knee, hands, and vertebrae.
Epidemiology of Osteoarthritis
- Females > males
- Age over 50
Aetiology/Risk factors
- Age >50
- Female sex
- Obesity
- Physically demanding occupation/sport
Site predilection:
- Joints of the hand
- Distal interphalangeal joints (DIP)
- Proximal interphalangeal joints (PIP)
- First carpometacarpal joint (CMC — base of 1st metacarpal)
- Weight-bearing joints of lower limbs
- Lumbar Spine
- Knees and hips
- 1st MTP — BIG TOE is very weight bearing
Presenting symptoms
- Joint pain
-
morning stiffness worse with movement
- morning stiffness in OA lasts <30 minutes as it is NON-INFLAMMATORY
- Reduced ROM
Signs on Physical Examination
- Asymmetrical oligoarthropathy
- Tenderness
-
Joint deformities/enlargement:
- Herberden’s nodes (osteophytes at DIP)
- Bouchard’s nodes (osteophytes at PIP)
- Crepitus
- Limited ROM
- Malalignment (varus or valgus)
Investigations for OA
-
X-Ray (Radiological findings): LOSS
- Loss of joint space
- Osteophytes
- Subchondral sclerosis
- Subchondral cysts
- erosive osteoarthritis will show
seagull appearance (this is distal, does not affect proximal)
- CRP & ESR are normal
- Join fluid aspiration: calcium phosphate crystals associated with degeneration of cartilage, coffin-lid shaped with negative birefringence
Types of OA
Primary OA: idiopathic
Secondary OA:
* Rheumatoid arthritis
* Septic arthritis
* Abnormal loading of joints:
* Obesity
* Meniscal tears
* Varus/Valgus deformities
Erosive OA: erosive changes seen on X-ray (erosions not normally seen in OA) –> the seagull sign is suggestive
