Bone and joint pathology Flashcards
How does low oestrogen increase bone resorption
In low oestrogen levels there is decreased osteoprotegerin (OPG). OPG usually acts as a decoy receptor for RANK, preventing the activation of osteoclasts by osteoblast (RANK-L) stimulation.
What is used for prevention of osteoporosis?
Calcium and Vit D3 and Bisphosphonates are first line.
Also: RANK-L inhibitors.
HRT no longer used due to increased breast and endometrial cancer risk.
When does peak bone mass occur?
20-30 years of age
What is the main protecting factor for osteoporosis?
Bone mass
What are the symptoms of osteoarthritis?
Joint pain, stiffness, functional impairment
Overall loss of quality of life
What causes osteoarthritis?
90% of cases are primary idiopathic. There are changes in proteoglycan and collagen leading to altered load bearing properties.
10% secondary: as a consequence of pre-existing joint disease.
e.g. deformity, RA, metabolic disorder, crystal deposition disease.
What is the pathology of Rheumatoid Arthritis?
Systemic autoimmune disease that manifests as synovial arthropathy (starts as sinovitis and changes spread to articular cartilage, subchondral bone and peri-articular tissue).
How do we treat RA?
Analgesics, NSAIDS and DMARDs first line.
If DMARDs don’t work use anti-TNF-alpha.
If that doesn’t work use immunotherapy (e.g. Rituximab).
Steroids are sometimes used short term for life-threatening complications or to suppress disease when DMARDs are being introduced.
Name 3 DMARDs
Methotrexate, sulfasalazine, hydroxychloroquine
How do we treat osteoarthritis?
Analgesia, exercise and bone protection (calcichew and bisphosphonates)
How do we treat gout?
NSAIDS, followed by colchicine, followed by steroids
What is sequestrum in osteomyeltitis
dead bone
What is involucrum in osteomyelitis
Layer of new bone growth surrounding the dead bone
Where is calcitonin produced?
The parafollicular (C cells) cells of the thyroid
What are the functions of PTH?
Regulates activation of vitamin D in the kidney (which then stimulates ca and P absorption in the gut and ca release from bone).
Increases resorption of Ca and decreases resorption of P in the kidney.
Releases Ca from bone.
What is rheumatoid factor?
An anti-IgG antibody
This is present in >80% of patients with RA, usually the IgM subtype.
Higher levels associated with worse prognosis
What method is used to detect rheumatoid factor?
Latex bead agglutination
Which autoantibodies would you expect to find in sjogren’s disease?
Anti-Ro (SS-A) and anti-La (SS-B) -these are ENA antibodies.
What is impetigo?
A pyogenic infection of the epidermis, usually caused by staph aureus
What is furunculosis?
Infection of sebaceous glands or sweat glands, usually causes by staph aureus.
What is cellulitis?
Infection of loose subcutaneous tissue- usually resulting from penetrating injury or local lesion. Usually strep pyogenes or staph aureus.
Which organism usually causes gas gangrene?
C. Perfringens
How long should antibiotics be given for in osteomyelitis? (Hint: consider acute, chronic and childhood infections)
Acute- 6 weeks
Chronic- 12 weeks (6 IV, 6 oral)
Acute in children- 2-4 weeks
Where is pain from the glenohumeral joint felt?
Over the upper arm
Where is pain from the acromioclavicuar joint felt?
In the joint
Where is rotator cuff pain felt?
Over the upper arm
What time of day is stiffness worst in inflammatory joint conditions?
Early morning, eases with activity
When are pain and stiffness from non-inflammatory joint conditions worst?
Exacerbated by activity
Knee pain can be felt in the knee or it can radiate- where to?
The hip or the ankle
Ankylosing spondylitis affects which areas of the body most?
Spine and sacroiliac joints
What is usually one of the earliest manifestations of ankylosing spondylitis?
Inflammation of the sacroiliac joint
How do we treat ankylosing spondylitis
Same as RA!
NSAIDS, opioids, DMARDS
What is a syndesmophyte?
A bony growth originating inside a ligament, commonly seen in the ligaments of the spine. Ankylosing spondylitis patients are prone to them, but also those who have had back surgery or other chronic stresses on the ligaments of the spine
Ankylosing spondylitis affects which areas of the body most?
Spine and sacroiliac joints
What is usually one of the earliest manifestations of ankylosing spondylitis?
Inflammation of the sacroiliac joint
How do we treat ankylosing spondylitis
Same as RA!
NSAIDS, opioids, DMARDS
What is a syndesmophyte?
A bony growth originating inside a ligament, commonly seen in the ligaments of the spine. Ankylosing spondylitis patients are prone to them, but also those who have had back surgery or other chronic stresses on the ligaments of the spine
What is onycholysis?
Detachment of nail from nail bed. Seen in psoriasis
What is hypertrophic pulmonary osteoarthropathy?
Condition combining clubbing and periostits of the small hand joints.
What is hypertrophic pulmonary osteoarthropathy associated with?
Lung cancer
How do we treat psoriatic arthritis?
NSAIDS, sulfasalazine, methotrexate, ciclosporin.
Anti-TNF agents may also be effective.
What is another name for giant cell arteritis?
Temporal arteritis
What are the symptoms of giant cell arteritis?
Aching and soreness around temples
Jaw muscle pain while eating
Vision loss
What is enthesitis?
Inflammation of site of insertion of a tendon or ligament into bone e.g. Plantar fasciitis, Achilles tendonitis, costochondritis
What are the radiographic features of RA?
Juxta-articular osteopenia, bony erosions, loss of joint space, soft tissue swelling
What would you see on a pseudogout X-ray?
Chondrocalcinosis
Joint space narrowing
Widespread cartilage loss
Treatments for pseudogout?
Just aspirate!
Colchicine
NSAIDs
Steroids
What is the most common cause of joint effusion of the knee?
Osteoarthritis
Which joints do Heberden’s nodes form in?
DIP joints
Which joints do Bouchard’s nodes form in?
PIP joints
What is the difference between a fixed and a flexible deformity?
In a flexible deformity some movement is possible.
What does Trendellenburg’s sign suggest?
Weakened or paralysed abductor muscles of the hip- gluteus minimus and gluteus medius
What is Thomas’ test used to assess?
Fixed flexion deformity of the hip
Which are more likely to cause polyarthritis: viruses or bacteria?
Viruses
Monoarthritis is more often caused by:
A) Bacteria
B) Virus
A) Bacteria
Which virus most commonly causes polyarthritis?
Parvovirus
What are the main differentials for monoarthritis? (name 6)
OA Gout Reactive Septic Trauma Avascular Necrosis
What is podogra?
Gout affecting the big toe
What kind of inflammatory cells are involved in gout?
Neutrophils
Name a xanthine oxidase inhibitor used in prevention of gout.
Allopurinol
What are the main systemic effects of gout?
Tophi in the skin. Renal calculi. Systemic inflammatory response. Fever. Anorexia. Metabolic syndrom.
What are the 5 types of OA?
1) Nodal generalized OA
2) Erosive inflammatory OA
3) Large joint OA
4) Crystal-associated OA
5) Secondary OA
What radiological features are seen in OA?
Joint space narrowing
Sclerosis
Subchondral cysts
Bone collapse/attrition
Osseus ('loose') bodies.When would you use steroids for RA?
As a bridge therapy before the onset of action of DMARDs
What are the most common causative organisms of reactive arthritis?
Gastrointestinal- e.g. Salmonella, shigella, campylobacter.
Sexually transmitted- e.g. Chlamydia trachomatis, neisseria gonorrheae
What is the mechanism of denosumab and what is it used for?
RANKL inhibitor used in osteoporosis
