Bone, Anaesthetics, Fracture and Soft tissue injury Flashcards
what is hydroxyapatite?
crystals of the mineralised matrix of bone- Ca10(PO4)6(OH)2
what is the metaphysis?
growth plate between the diaphysis and epiphysis
what are the layers of lamellar bone?
there is an outer layer of cortical (compact) bone and an inner layer of trabecular (spongy) bone
what is the endosteum?
an inner lining which forms the boundary to the central medullary cavity
what is woven bone?
newly calcified, immature bone which has an irregular arrangement of collagen fibres. forms during development and healing
what is the structure of lamellar bone?
there are structures called osteons which are layers of lamellae (layers of collagen fibres) surrounding a central Haversian canal with osteocytes trapped within lacunae. canaliculi form connections between lacunae
how are the lamellae organised?
each lamellae has collagen fibres arranged at 90 degrees to the adjacent lamellae. this organisation gives strength to the bone
what is the function of trabecular bone?
keeps the bones light whilst maintaining structural integrity
what is the mechanism of action of local anaesthetics?
they block initiation and propagation of action potentials by blocking Na channels thus preventing the voltage dependant increase in Na
why would you co-administer adrenaline with a local anaesthetic?
vasoconstrictor- reduces blood flow to the area so the local anaesthetic isn’t cleared as quickly so it is more effective
what are the major side effects of local anaesthetics?
allergy, redness of skin
CNS stimulant/depressant effects- restlessness, tremor, respiratory depression
myocardial depression
vasodilation- BP drop
what is the clinical use of propafol and thiopental sodium?
both IV anaesthetics
propafol- used for induction/maintenece of anaesthesia in adults/ children (not neonates)
thiopental sodium- bibiturate used for induction of anaesthesia only
what is isoflurane?
widely used volatile liquid anaesthetic- inhalation
how can ultrasound be used in musculoskeletal disease?
ultrasound can be used to help diagnose: tendon tears/tendonitis muscle tears, masses or fluid collection inflammation or fluid within joints nerve entrapments
what is the approach used to treat fracture?
identify mechanism of injury- if high energy- ABCDE
wound care- cleaning
pain management- immobilisation, analgesia
imaging
fracture care- reduction and immobilisation (plaster, splint) or surgical fixation
what are the symptoms of fracture?
pain deformity bone crepitus abnormal mobility associated soft tissue injury neuromuscular compromise
how are fractures classified?
growth plate involvement- skeletally mature/immature
location- which bone, proximal/distal, inter-articular, diaphysis, epiphysis
extent- complete/incomplete
orientation- transverse/ oblique/ spiral
displacement- non-displaced/ displaced
fragmentation- comminuted (multiple pieces)/ segmental (fracture in two places)
soft tissue- open/closed
pathological- due to pre-exisiting pathology
what are the complications of fracture?
neuromuscular injuries compartment syndrome infection- open fracture/ surgery long- term- stiffeness, arthritis, growth disturbance DVT/PE
what are the types of soft tissue injury?
penetrating- incised wound, laceration
blunt- bust laceration, crush, de-gloving, avulsion, amputation
burns- superficial/full thickness
tendon injury- division, rupture, avulsion
nerve injury- division, traction, compression
what patterns of motor and sensory loss occur with femoral nerve injury?
sensory- anterior thigh, medial leg (via saphenous nerve)
motor- knee extension
what patterns of motor and sensory loss occur with sciatic nerve injury?
sensory- lateral leg via branches
motor- hip extension/knee flexion
what patterns of motor and sensory loss occur with tibial nerve injury?
sensory- sole of foot
motor- plantar flexion, toe flexion
what patterns of motor and sensory loss occur with superficial peroneal nerve injury?
sensory- lateral side of lower 2/3 of leg, dorsum of foot (except 1st web space)
motor- ankle eversion
what patterns of motor and sensory loss occur with deep peroneal nerve injury?
sensory- 1st web space
motor- ankle dorsiflexion (foot drop), toe extension
what patterns of motor and sensory loss occur with sural nerve injury?
sensory- posterolateral leg
