Pathology Flashcards
Osteomyelitis
Describe the pathology of the condition.
begins generally in metaphysis because the capillary loops of the nutrient artery terminate here → slow blood flow → bacteria able to penetrate wall of the capillaries → establish a foci for proliferation of the bacteria in the marrow → localised suppurative response leads to obstruction of blood supply to the bone → ischaemia → bone becomes necrotic → separates from viable surrounding bone → sequestrum.
Pus formation → purulent exudate extends into endosteal vascular channels that supply the cortex → pus under the periosteum →pus builds up between cortex and periosteum damaging blood vessels → eventually penetrating the periosteum → finds its way to surrounding soft tissue via a draining sinus called a cloaca → abscess formation.
Reactive periosteal bone formation in a response to the destruction results in a sheath of new bone called an involucrum
What causes a slight “moth-eaten” appearance in the distal metaphysis of the femur,
Osteomyelitis
What does RA stand for?
Rheumatoid Arthritis
Where would you find Carpal tunnel syndrome?
Wrists
What is Carpal tunnel syndrome?
Compression of the median nerve could be caused by:
Reduction of the tunnel capacity, i.e. bony or ligament changes
Increase in the volume of the tunnel contents i.e. inflammation of the tendons, synovial swelling, tumours, and oedema in the wrists.
What systemic disease can Carpal tunnel syndrome be a feature of?
rheumatoid arthritis, and diabetes mellitus.
What can cause Carpal tunnel syndrome?
It could result from wrist injury, could occur during pregnancy, use of birth control drugs, in labourers with repetitive use of the wrists.
What are the four articular clinical manifestation of Rheumatoid Arthritis (RA) in the hand
- usually bilateral and symmetric involvement of proximal interphalangeal (PIP) and metacarpophalangeal (MCP) joints
- Fingers spindle-shaped due to inflamed PIP joints
- Subluxation of joints with joint deformities leading to ulnar deviation of fingers (swan neck deformity = hyperextened pip joint and flexed dip joint)
- Fixation of joints (Boutonnière deformity = flexed pip joint and hyperextended dip joi
What fracture looks like a dinner fork?
Colles fracture
Describe a Colles fracture?
A fracture of the distal end of the radius in which the distal fragment is displaced posteriorly. 60% of cases have an accompanying fracture of the ulna styloid process.
The fracture line is usually transverse and comminuted. A sharp cortical overlap is seen on the radius at the fracture site with some impaction. The radial length is decreases.
Describe the pattern (appearance) of a Scaphoid fracture
Often missed. Fracture line transverse in relation to the long axis of scaphoid. The position of the fracture has a bearing on healing and complications. A fracture through the waist (70%), proximal pole (20%), or distal pole (10%)
Plain film radiographs reveal bony disruption to the proximal fifth metatarsal
Describe the radiographic appearance of this type of trauma
Jones’ fracture involves a fracture at the base of the fifth metatarsal which typically extends into the 4-5 intermetatarsal facet; - Jones fracture is located within 1.5 cm distal to tuberosity of 5th metatarsal
What is a Jones’s fracture look like on film radiographs?
Bony disruption to the proximal fifth metatarsal.
Where would you find a Tuff’s fracture?
Fingers
Where would you find a Boxer fracture?
Hand
