What is the benefit of doing an x-ray early on in osteomyelitis?
Rules out fracture and malignancy
Which cells produce osteoid?
What stimulates PTH release?
Which bone cells does PTH act on directly to increase calcium?
What are the 3 organs that PTH acts on to increase calcium levels?
Bone, kidney and GIT
What type of collagen is in hyaline cartilage?
Where are the 3 places that elastic cartilage is present?
Ear, epiglottis and thyroid cartilage
What are osteocalcin and alkaline phosphatase both markers of?
What are the little tubes that provide nutrients to osteocytes?
What is a displaced fracture?
Edges of fracture are not apposed
What causes a stress fracture?
Repeated low force injury to a normal bone
What are the 4 stages of fracture healing?
Inflammatory Reparative - Soft callus Reparative - Hard callus Remodelling
What are the 2 major processes during the remodelling phase of fracture healing?
Osteoblasts and osteoclasts repopulate the bone Woven bone is remodelled to give lamellar bone
Over what time frame does the hard callus phase of fracture healing occur?
Weeks to months
Over what time frame does the remodelling phase of fracture healing occur?
Months to years
What kind of fracture is most susceptible to infection?
What is the definition of osteoporosis?
Bone mass >2.5 SDs below the mean for healthy young women
What is the definition of osteopaenia?
Bone mass 1-2.5 SDs below the mean for healthy young women
What is the main concern with long term bisphosphonate treatment?
What are the 2 main risks of long term oestrogen therapy for bone health?
Cardiovascular disease and breast cancer
Is sarcopenia inevitable?
What effect does VitD have in the gut?
Increases absorption of Ca and PO4 (phosphate)
What are the 2 major processes during the hard callus phase of fracture healing?
Osteoblasts synthesise osteoid Osteoid becomes mineralised
What class of hormone is VitD?
At what age does muscle mass start to deteriorate?
50 years old
What is the most common form of calcium phosphate in bone?
What is the difference between the actions of PTH and VitD3 in the distal nephron?
PTH causes phosphate excretion, whereas VitD3 promotes phosphate reabsorption
What word means progressive loss of skeletal muscle mass with aging?
What is the motor uni?
An alpha motor neurone and all muscle fibres it supplies
Which protein is abnormal in Becker muscular dystrophy?
What are osteocalcin and osteonectin?
Calcium binding proteins in the ECM of bone
Which bone cells produce collagen for cartilage?
What is the second common pathogen in osteomyelitis?
Strep pyogenes / Group A strep
Which pathogen is more common for osteomyelitis after a sneaker penetration injury?
What protein is a marker of muscle damage?
What causes progressive stiffening of muscle fibres with age?
Loss of elastin
Which gene can be knocked out in mice to cause massive muscles?
Progressive loss of skeletal muscle mass and strength or performance with aging
In which 2 structures is fibrocartilage found?
Menisci and intervertebral discs
What percentage of muscle mass must be lost before there is the risk of mortality?
How does denosumab treat osteoporosis?
It is a human monoclonal antibody that binds RANKL and iblocks RANK activity => reduces osteoclast activity
What type of collagen is in fibrocartilage?
What is a compound fracture?
Open fracture, ie bone exposed to external world
What are the 2 major processes during the inflammatory phase of fracture healing?
Haematoma and granulation tissue
What are the 2 layers of the periosteum?
Inner cellular layer with osteoprogenitor cells Outer fibrous layer
Which bone cells are multinucleate?
In what direction do osteoclasts dig their holes in bone?
Along the stress axis of the bone
What are osteons aka?
What is at the end of a bone? (-physis)
What are the main types of muscle atrophy?
What is a comminuted fracture?
Fracture with more than 2 bits of bone
What percentage of cases of osteomyelitis occur in children <5 years old?
Over what time frame does the soft callus phase of fracture healing occur?
Days to weeks
What is osteomyelitis better known as?
What is the proper way to say 'bone infection'?
Which bones are most commonly involved in osteomyelitis?
Long bones: femur, tibia, humerus
What is a pathological fracture?
Fracture where underlying bone pathology has made it more vulnerable to fracture
How do tendons and ligaments attach to bone?
What is raloxifene?
Selective oestrogen receptor modulator
What are bisphosphonates used to treat?
In which 3 locations is red bone marrow found in adults?
Skull, scapula and pelvis
Which protein is abnormal in Duchenne muscular dystrophy?
What is the scaffolding for bone that is laid down by osteoblasts?
What do we call infection of a joint?
What percentage of the body's calcium is in bone?
What effect does oestrogen have on bone?
Maintains bone density by promoting osteoclast apoptosis and increasing life span of osteoblasts and osteocytes
Which cells resorb bone?
How is most calcium lost from the body?
What is the main complication with a compound fracture?
Which cells are osteoblasts modified from?
What is a greenstick fracture?
Only one side of cortical bone is broken
How do bisphosphonates work?
They are an analogue of pyrophosphate thus taken up into bone matrix Taken up by osteoclasts, causing apoptosis
What do osteoclasts secrete?
HCl and proteases
What effect does PTH have on [Ca2+] in plasma?
How long do most lower limb fractures take to heal?
What can be done to attenuate sarcopenia?
Decreases in which 3 hormones are thought to be related to sarcopenia?
Growth hormone, IGF-1 and testosterone
What do osteoblasts turn into when they are less active?
What is the name of the process by which long bones grow in length?
What effect does PTH have on plasma [phosphate]?
What is another name for cortical bone?
Which cells build bone?
Which two conditions are especially common in travellers to Asia?
Dengue fever and typhoid fever
Which cells are responsible for ongoing maintenance of cartilage?
What is calcitriol?
How long do most upper limb fractures take to heal?
What is a complete fracture?
A bone is broken all the way through
What is the most common pathogen in osteomyelitis?
How does PTH increase VitD levels?
PTH activates the kidney enzyme to hydroxylate/activate VitD3
What are 4 synonyms for the inner bit of a bone?
Medullary; cancellous; trabecular; spongy
Which NSAID should not be given for gout?
What does PTH cause osteoblasts to do?
Release OPG and RANK ligand to activate osteoclasts
What is Gower's sign?
Muscle weakness causes difficulty getting of floor, so Pt uses accessory muscles such as arms to help themselves get up
What is a sarcolemma?
Cell membrane of skeletal muscle
Where do osteoprogenitor cells usually reside?
Periosteum or endosteum
What type of muscle is more susceptible to sarcopenia?
What is the goal of management of a fracture?
Unite the ends of the fractured bone
Over what time frame does the inflammatory phase of fracture healing occur?
What is the antibiotic of choice for osteomyelitis?
What are the 2 major processes during the soft callus phase of fracture healing?
Progenitor cells turn into chondrocytes Chondrocytes form cartilage
What is the role of dystrohpin?
It i links actin in the cytoskeleton to laminin via glycoproteins
What is at the middle of a bone? (-physis)
What type of cell is in hyaline cartilage?
Name 4 things found inside a Haversian canal
Capillary, nerve, supportive connective tissue and lymphatic
For joint pathology, what will be the consequence of fibrillation and sloughing of articular cartilage?
Loss of joint space
For joint pathology, what will be the consequence of calcification of periarticular cartilage and synovium?
For joint pathology, what will be the consequence of synovial fluid entering bone?
For joint pathology, what will be the consequence of thickening of subchondral bone and trabeculae?
What are the 4 main components of hyaline cartilage?
Type 2 collagen
What type of blood vessels are present in hyaline cartilage?
What type of nerves are present in hyaline cartilage?
How is hyaline cartilage nurished?
Perfusion by compression and decompression of the cartilage
What is added to plasma filtrate in the formation of synovial fluid?
What are the two types of cell in synovium?
Type A cells (macrophage-like)
Type B cells (fibroblast-like)
Give a 4 word definition of the pathophysiology of osteoarthritis
Chronic degeneration of cartilage
Which disease is characterized by degeneration of cartilage that results in structural and functional failure of synovial joints?
How would you explain osteoarthritis to a lay person in 5 words?
Wear and tear of joints
At what time of day is pain from osteoarthritis worse?
At the end of the day
Pain at the end of the day suggests what type of arthritis?
Which joints tend to be most affected by osteoarthritis?
At what time of day does pain from rheumatoid arthritis tend to be worst?
In the morning
Morning stiffness of joints suggests what type of arthritis?
Which disease is characterised by autoimmune inflammatory joint disease with systemic involvement?
What is podagra?
Gout in the great toe
What do we call gout in the big toe?
due to accumulation of uric acid crystals
in a joint
In which part of bone would you find osteons?
What are 3 signs of osteoarthritis?
What are 3 microscopic pathological features of rheumatoid arthritis?
Synovial hyerplasia forming pannus
List 3 signs of rheumatoid arthritis
Destruction and deformity of joints
Which joints of the hand are often spared in rheumatoid arthritis?
Distal interphalangeal joint
What diagnosis should you consider when someone presents with swollen joints, nodules and deformed joints?
What is the prevalence of rheumatoid arthritis?
1% of the population
List 3 x-ray features of rheumatoid arthritis
Uniform joint space loss
What percentage of rheumatoid arthritis is genetic?
List 3 risk factors for rheumatoid arthritis
Accumulation of what causes gout?
Uric acid crystals
What are tophi?
Uric acid crystal depositions in soft tissues other than joints
What is the cardinal sign of gout?
Acutely inflamed, intensely painful joint
What type of inflammation is caused by tophi?
What is the gold standard diagnostic test for gout?
Joint or tophus aspiration during an acute attack