Osteoarthritis Flashcards
What are the cells that build and maintain the ECM of cartilage?
Chondrocytes (from mesenchymal stem cells)
What components are found within the ECM of cartilage?
Collagen type 2 (type 1 in fibrous)
Proteoglycans
Glycosaminoglycans -Hyaluronic Acid Chains (links contain chondroitin and keratan sulphate)
What are the 3 types of cartilage?
Hyaline (articular), Elastic (ear/nose), Fibrocartilage (pubic ramus, meniscus)
Where is subchondral bone found?
At joints, beneath the articular cartilage, superficial to the trabeculae of bone
What are some observable differences in normal vs osteoarthritic joints?
Osteoarthritic joints tend to have:
- Reduced articular cartilage
- Cysts formation in subchondral bone due to synovial fluid leaking through cartilage
- Osteophytic lipping (outgrowth of bone)
- Shelving fibrillated cartilage (softening, forming of vertical clefts, spaghetti like appearance)
- Synovial hypertrophy
- Thickened capsule
- Altered contour of subchondral bone
What components make up a normal synovial joint?
Capsule Synovium Synovial Fluid Articular Cartilage Subchondral bone/ bone
What is the role of hyaluronic acid chains and proteoglycans within the ECM of cartilage?
They protect the chondrocytes from loading forces
Explain the pathogenesis of Osteoarthritis, talking about fluid content, and functional loss of different components within the joint.
Initial increase in water (caused by aggrecan exposure) which makes cells swell and changes loading pattern.
Water loss in cells then occurs (aggrecan breakdown), ECM is not as robust, decreased proteoglycans (which cushion and aid in homeostasis) causing less collagen cross linking (weakening), main structure of cartilage is lost
Spurs and cysts at the margin then occur
Is it the most common joint disease?
Yup
What is the most common age group impacted by osteoarthritis?
over 45
Is osteoarthritis more prevalent in males or females?
Females (in ages 45+)
Males (in <45 years)
What is the primary cause of osteoarthritis?
Degeneration
What are secondary causes of osteoarthritis?
Trauma (more common in <45yrs)
Hip dysplasia
Infection (cartilage and bone destroyed)
Diabetes
What are risk factors for osteoarthritis?
Age
Genetics (small)
Gender
Nutrition
What are some joint biomechanical risks to osteoarthritis?
Joint trauma
Obesity
Occupation (manual labour)
Abnormal joint biomechanics (typically born with it)
What are the key symptoms of osteoarthritis?
Pain during load bearing activities
Stiffness in morning for less than 30 min
Difficulty moving the affected joints doing certain activities
Stiffness
Sleep disturbance
How do you diagnose osteoarthritics?
X-Ray
Joint space narrowing
Osteophytes (extra pieces of bone at joint periphery)
Cyst formation
Subchondral Sclerosis at weight bearing portions of joint (seen as white lines on x-ray)
What is the management of osteoarthritis?
Manage symptoms, it cant be cured Medication Joint injections Physiotherapy Surgical (last resort)
What are examples of types of medications that can be used to treat osteoarthritis?
Paracetamol,
Non-steroidal anti-inflammatories drugs (Ibuprofen, Diclofenac),
Chondroitin Sulphate or Glucosamine (for articular cartilage repair)
How can physiotherapy help treat osteoarthritis?
Strengthening muscles
Aerobic conditioning (weight control- reliefs weight on joint)
Range of motion exercises
How are injections used to treat osteoarthritis?
Less common
Cortisone/ Corticosteroids- reduces inflammation and pain, more rapid than NSAIDs
Viscous supplement- replace synovial fluid, increase viscosity
What are surgical ways to treat severe osteoarthritis?
Arthroscopy (look at joint) Cartilage transplantation (rare- typically for younger patients or well defined (<1.5cm) osteoarthritis) Joint replacement- most successful
When would uni-compartmental knee replacement be used?
When only one side of the knee joint has osteoarthritis, you replace the affected side
When is cartilage transplantation used?
When osteoarthritis is VERY well defined (less than 1.5cm lesion), and the transplant may be successful n preventing the progression of the disease
What are the types of Osteo-articular transplants?
Autologous chondrocyte implantation from a non-weight bearing joint
Cadaver allograft
What is the trendelenburg sign?
Dropping of the hip, unilaterally, when standing straight
