Orthopaedics Flashcards
what are the non-surgical management methods for fracture fixation?
external coaptation
conservative
what are the surgical management methods for fracture fixation?
pin and wire
external skeletal fixation
plate and screw
what are the principles of fracture fixation?
return the patient to normal function as soon as possible
create circumstances which allow bone healing to be optimal
what are the potential advantages of non-surgical management?
reduce/avoid anaesthesia
avoid need for open surgical approach
cheaper materials
cheaper overall? (may end in surgery anyway)
what are the potential disadvantages of non-surgical management?
fracture disease
insufficient stability, leading to delayed/non-union
malunion
cast sores, ischaemia
what are the principles of conservative fracture management?
surrounding soft tissue provides sufficient stability to keep bones aligned whilst healing
minimise movement whilst healing - restrict exercise, prevent weight-bearing
which fractures are suitable for conservative management?
selected fractures of pelvis, scapula or vertebra
stable, minimally displaced fractures
how long do fractures typically take to heal with conservative management?
4-6 weeks
possibly less in younger animals
what can be used to prevent weight bearing on scapular fractures?
carpal flexion bandage
velpeau sling
what information needs to be given to owners of animals undergoing conservative fracture management?
cage size and contents prevention of boredom nursing care decubitus ulcer prevention provide non-slip rugs and ramps
what is external coaptation?
compressive forces transmitted to bones by means of interposed soft tissues
which joints must be immobilised in external coaptation?
immobilise joint above and below fracture
this principle extends to all joints distal to the fracture to avoid foot swelling
which fractures are suitable for coaptation?
fractures distal to elbow or stifle
stable fractures
50% overlap of fracture fragments on orthogonal radiographs
fracture of one bone of a 2 bone segment (e.g. radius and ulna)
2 or fewer metatarsal/metacarpal fractures
what is the first layer of a cast?
‘stockinette’
double layer, long enough for overlap top and bottom
hold taut so doesn’t ruck up
what is the second layer of cast?
primary layer - soffban water-repellant, conformable bandage 1-2 50% overlap layers not too much padding over bony prominences allow excess top and bottom for overlap
what is the third layer of cast?
cast material - fibreglass impregnated polyurethane
lightweight, comfortable, waterproof, radiolucent, fast setting
wear gloves!
how do you apply the cast material?
immerse in water and squeeze 6 times
apply under a little tension
average of 6 layers (3 up and downs) - more at bends
avoid wrinkles
what should you do once the cast material has set? why?
bivalve using a cast saw while dog still sedated/under GA
for ease of removal if problems or if another vet does not have a cast saw
what should you do with the cast once it has been bivalved?
secure it firmly using strips of non-stretchy tape (zinc oxide tape)
how do you protect against sharp ends of cast?
fold over sofban and stockinette - apply extra padding as necessary to avoid sharp edges
reinforce foot area with extra tape (wears through)
what is the final layer of cast?
outer protective layer - vetrap (cohesive bandage)
what final check should be done once the cast is in place?
make sure toenails and central pads are visible but not protruding
why is the complication rate of external coaptation high?
inappropriate case selection
owner compliance
difficulties in management
what is the most common complication of external coapation?
soft tissue injury - ischaemic injury
mild dermatitis to avascular necrosis
what structural complications can arise from external coaptation?
may heal with rotation, angulation and/or shortening
may be functional or non-functional depending on degree/severity
how does fracture disease occur?
occurs during the time necessary for the bone to heal and is a result of fracture management
what can result from fracture disease?
joint stiffness
muscle atrophy
osteoporosis
muscle contracture and fibrosis
how can fracture disease be avoided?
aim for a rapid return to weight-bearing
avoid unnecessary immobilisation of joints by external coaptation
consider other options that cause less fracture disease e.g. ESF or internal fixation
what is the nurses role in surgical fracture repair?
analgesia provision and patient care prior to surgery
aseptic surgical prep
equipment gathering and setup for theatre
trolley assistant for surgery
post-operative care of the patient
discharging patient to owner
what trolley setup can make fracture surgery easier?
tidy instruments with handles all in same direction
separate tray for sharps
needles separate
commonly used instruments in separate tray
what type of drape is used in fracture surgery?
adhesive drape (opsite/loban)
is the foot clipped for fracture surgery?
only if directly involved in surgery - must always be covered regardless
what is fracture reduction?
the process of replacing the fracture segments in their original anatomical position
which injuries are suitable for closed fracture reduction?
recent/stable fractures
lower limb fractures - less soft tissue, easier to reduce and palpate
which methods are used for closed fracture reduction?
traction and counter-traction
manipulation
bending
what is the main barrier in open fracture reduction?
overcoming muscle contraction
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how can we overcome muscle contraction during open fracture reduction?
levers (Hohmann retractors)
bone holders
muscle relaxants
why aren’t muscle relaxants always used to overcome muscle contraction?
often don’t respond well as the tissue is inflamed
what is toggling?
bending the fracture 180° to engage the ends, then straightening the limb in order to position the bone straight for stabilisation
which fractures are suitable for toggling?
transverse fractures
what types of implants are used in fracture repair?
pins wire screws external skeletal fixation plate and screws
can intramedullary pins be used alone?
rarely - do not prevent rotation at the fracture site
what are intramedullary pins often combined with?
plate or ESF
when are intramedullary pins used alone?
metacarpal/metatarsal repair - splinted by other bones
what are the complications with using intramedullary pins?
length - too long/short and won’t stabilise fracture effectively + difficult to retrieve
too long will result in seroma formation
loosening and migration
fracture non-union
what is an interlocking nail? why is it used?
stainless steel pin used as intramedullary pin - locked in place using screws/bolts
prevents rotation and axial collapse
what materials are bone plates/screws made out of?
stainless steel or titanium alloy
what is the function of bone plates?
compression of bone fragments
what is the effect of bone compression?
friction - increases stability
primary bone healing
load-sharing between bone and implants
what is bridging fixation?
plate is used to shore up/support fragments in unreconstructable fractures
uses a larger plate
what are the different uses for bone screws?
combination with a plate or interlocking nail
used in isolation for fractures of cancellous bone (never for diaphyseal)
why aren’t bone screws ever used in isolation for diaphyseal fractures?
slower healing and greater forces through bone
what different types of bone screws are there?
locking screws
self tapping
non-self tapping
what are the functions of a bone screw?
secure a plate to a bone to support a fracture during healing
to compress fragments together in lag fashion to enable rapid healing without a callus
where is it important to avoid callus formation?
in fractures close to a joint
how should you treat an articular fracture?
open reduction and internal fixation
compression
perfect reduction
maintenance of joint mobility
when are smooth bone pins used?
rarely as don’t hold bone well
sometimes used if very small pin required
what types of threaded pins are there?
negative (Ellis) or positive (Imex) profile
end threaded (positive or negative)
centrally threaded (positive only)
interface pins (roughened to help stick to putty)
when is putty used?
to replace bars and clamps
what is the advantage of using stainless steel/carbon connecting bars?
reusable
what are the disadvantages of using stainless steel/carbon connecting bars?
heavy (carbon light)
all clamps need to be in a straight line
what are the advantages of using acrylic/putty?
light
no limit to pin size/closeness
no protruding pin ends which might irritate
what is the disadvantage of using acrylic/putty?
removal is more difficult
what are clamps used for?
connecting pins to bars
what are the advantages of using clamps?
reusable if not deformed
makes adjustments and pin removal easier
what are the disadvantages of using clamps?
limit to pin and bar size
need to be constructed correctly
what is a tied-in IM pin?
the IM pin is left long and connected to the ESF via a separate connecting bar or by bending the bar
what is the advantage of using a tied in IM pin?
IM pin can’t migrate/loosen - increases stability of the whole structure
which bones are prone to avulsion fractures?
olecranon greater trochanter medial malleolus acromion of scapula os calcaneus tibial tuberosity
what is the tension band wire principle?
active distracting forces are counteracted and converted into compressive forces
what is the role of the surgical assistant during fracture repair surgery?
managing the surgical table and passing instruments correctly
assisting with surgical retraction and haemostasis
ensuring that diagnostic samples are not lost and transferred appropriately to sample pots
keeping bone graft safe and reminding the surgeon to use it
keeping count of surgical swabs
running a continuous suture and cutting sutures
how should you pass instruments to the surgeon?
in a decisive manner
tip of instrument visible and handles placed in surgeons waiting hand in proper position for use
don’t reach behind a member of the sterile team
what should be carried out post-op?
post-op x-rays
discussion of physio
what information should be given to the owners post-op?
cage rest information
timeframe of when weight-bearing should occur
suture removal information
buster collar info
prognosis
warn about possibility of premature closure of growth plate in young animals
what complications might occur post-op?
fracture instability
loosening
breakage
delayed or non-union
what should owners be looking out for post-op?
lameness change in limb use change in shape swelling discharge
what is the purpose of orthopaedic first aid?
to minimise injury and future disability
to keep the patient alive in serious cases
what are the 3 aims of orthopaedic first aid?
preserve life
prevent suffering
prevent deterioration
what is triage of the trauma patient?
a methodical initial assessment to rapidly identify the major life threatening injuries
what do we check in triage of the trauma patient?
airway breathing circulation external haemorrhage CNS function
what possible oral/skull reasons could there be for a patient having difficulty breathing following trauma
head trauma/fractures (skull, maxillary)
blood clots
ruptured trachea
how do you assess the airway during the primary survey/what are we checking for?
check mouth for obstruction (blood clot, foreign body) nostril blockages tongue swollen/lacerated hard palate split swelling around larynx
how do we check breathing during the primary survey?
breathing rate/effort/adequacy
what might have occurred if a cat has blood around nose, excess saliva, and inability to close the mouth
fractured jaw
how can we check circulation during the primary survey?
mm colour CRT heart/pulse rates, pulse quality rectal temperature peripheral pulses and temperature
what are the symptoms of mild shock?
mild tachycardia and tachypnoea
darker pink mm
CRT <1 second
normal mentation and BP
what are the signs of early decompensated shock?
tachycardia and tachypnoea pale mm slow CRT weak pulse poor mentation hypotension
what what point of shock should we give the patient fluids?
early decompensated
what are the signs of late decompensated shock?
bradycardia absent CRT severe hypotension cheyne stokes breathing death
when should we assume RTA patients have severe injury?
until proven otherwise
how should we transport recumbent RTA patients?
on an improvised stretcher
what is a secondary survey?
thorough check of body systems if primary survey ok/patient stabilised
what does A CRASH PLAN stand for?
A - airway - nose/larynx/neck/thoracic inlet
C- cardiovascular (CRT, pulse, BP) R - respiratory (chest wall, lungs) A - abdomen (diaphragm, inguinal, flank, paracostal) S - spine H - head (eyes/ears/mouth/teeth/tongue)
P - pelvis (rectum, perineum, scrotum, vulva)
L - limbs
A - arteries and veins
N - nerves (cranial and peripheral)
when is the secondary survey performed?
only after successful resuscitation and stabilisation of life-threatening injuries is the history taken and the thorough physical examination performed
what are the main signs of orthopaedic injury?
recumbency/severe lameness
limb wounds with pain/swelling
deformity
abnormal mobility/instability of limb
crepitation (due to bone-bone contact)
what is a luxation?
dislocation
complete disruption of normal relationship between articular surfaces of a joint
what are the major types of orthopaedic injury?
fractures
luxations
subluxations
wounds penetrating joints
tendon lacerations/avulsions
ligament strains
muscle lacerations
(all soft tissue injuries)
what is a fracture?
a disruption in the cortical continuity of a bone - can be complete or incomplete
what is an incomplete fracture?
not across full bone, only one cortex affected
seen in young animals due to flexibility of bone
what is sub-luxation?
partial disruption of relationship between articular surfaces of a joint
why is water soluble jelly used in management of open contaminated wounds?
to protect wound and prevent hair falling in while clipping
which order should be used in management of open contaminated wounds?
give analgesia and antibiotics therapy ASAP apply water soluble jelly clip flush debride bandage
what equipment is required for management of open contaminated wounds?
water soluble jelly clippers fluids for flush scalpel to debride necrotic tissue bandage for stabilisation
what is involved in first aid for open fractures/luxations?
treat as for laceration
apply sterile hydrogel to exposed articular cartilage and/or bone
support dress the injured limb, attempting to restore normal anatomy
should patients undergoing orthopaedic first aid be cage confined?
yes - unless only minor injuries
confinement will help prevent further injury through restricting movement
can we attempt to reduce luxations/fractures in the conscious patient?
no - too painful
can we attempt to stabilise proximal limb injuries in the conscious patient?
no - only below stifle/elbow
not possible with external coaptation, must be internal repair
why is it not possible to stabilise proximal limb injuries with external coaptation?
muscle will stabilise these joints
difficult to support joints above and below
what are orthogonal radiograph views?
views at 90° to each other
what else can be done while the patient is under GA for radiography?
wound care
splint/bandage application
reduction of luxation/fracture (if simple transverse fracture)
when might it be possible to support dress a limb in reduction/near reduction?
some distal injuries with torn ligaments and tissues resulting in marked laxity
how can you dress unstable fractures to support them?
use soft padding, then splinting material
then conform and outer protective layer
what splinting materials are available?
fibreglass resin - activated by water (5 min to harden)
orthoboard - plasticised cardboard, mould in hot water
thermoplastic - heat in water/use heat gun
plaster of paris - activated by water (long time to set)
what are the 4 layers of bandaging?
dressing - wet to dry/cotton wool (melolin/absorban)
sofban (water repellent)/swabs
conforming layer
vet wrap
what are the functions of a bandage?
protection
support for fracture/luxation/pre and post-surgery
pressure (haemostasis/swelling control)
immobilisation
where are support dressings useful in first aid?
stabilisation of distal limb only - support joint proximal and distal to injury
what are some of the different shapes of splint?
green gutter
tongue depressor
custom made splint using cast material
what does a robert jones bandage achieve?
immobilisation of fracture/luxation
control swelling and oedema
comfort
how do we provide first aid for bleeding?
treat as for laceration
apply a sterile contact layer, then generous padding using an absorbent layer (cotton robert jones)
apply pressure 30 mins-1hour for arterial bleed
what is hip dysplasia?
a developmental disease where laxity develops in the joint capsule, which allows hips to subluxate
what is the aetiology of hip dysplasia?
combo of genetics, size (larger breeds), diet, exercise
what is the common signalment associated with hip dysplasia?
mainly affects large/giant breed dogs (can affect small breeds and cats)
how does hip dysplasia manifest in young dogs (4-12 months)?
laxity
how does hip dysplasia manifest in adult dogs?
osteoarthritis
what can be seen with gait analysis of an animal with hip dysplasia?
short strides, stiffness, clunking of hips
lateral swaying
bunny hopping
adducted hindlimbs
what can be seen on orthopaedic examination of an animal with hip dysplasia?
pain on hip extension
clunking
hindlimb muscle atrophy
crepitus
what can be seen on an x-ray of an animal with hip dysplasia?
hip subluxation
acetabular remodelling
osteophytes
what x-ray position should be used for suspected hip dysplasia?
ventrodorsal extended - very important for hips to be straight
which test can be used to confirm hip dysplasia?
ortolani test (test of hip laxity) - dog in dorsal/lateral recumbency and stifles rotated outwards
will be negative if normal or just dislocated hip
what are the non-surgical treatment options for hip dysplasia?
osteoarthritis management - NSAIDs, rest, hydrotherapy, diet
what are the surgical treatment options for hip dysplasia?
juvenile pubic symphysiodesis (young dogs)
triple/double pelvic osteotomy (young dogs)
total hip replacement
femoral head and neck excision
what is avascular necrosis of the femoral head?
lack of blood supply to the femoral head, causes tissue death
what is the aetiopathogenesis of avascular necrosis of the femoral head?
trauma
ischaemia
small breed disposition
inherited basis with an autosomal inherited gene
what are the clinical signs of avascular necrosis of the femoral head?
unilateral hindlimb lameness
pain on hip extension and flexion
muscle wastage
what will be seen on a radiograph of a dog with avascular necrosis of the femoral head?
lucent areas initially
collapse and mushrooming of the femoral head as disease progresses
how can avascular necrosis of the femoral head be treated?
surgery - femoral head and neck excision; total hip replacement
conservative - cage rest
what is the prognosis for avascular necrosis of the femoral head?
guarded - usually requires salvage surgery
what is slipped capital femoral epiphysis?
damaged growth plate resulting in separation of the femoral head from the femoral neck
what are the clinical signs of slipped capital femoral epiphysis?
lameness and hip pain
atraumatic - often not acute onset of lameness
which animals are more likely to be affected by slipped capital femoral epiphysis?
young, male, neutered cats (<2 years), overweight/large breed
why does castration influence development of slipped capital femoral epiphysis?
castration delays growth plate fusion
what radiographic changes are seen with slipped capital femoral epiphysis?
radiolucent line at capital physis
separation/movement between femoral head and femoral neck
resorbtion of femoral neck
what is the treatment for slipped capital femoral epiphysis?
salvage surgery -
femoral head and neck excision
total hip replacement
parallel pin
what is the prognosis for slipped capital femoral epiphysis allowed to head spontaneously?
guarded for healing - usually do not heal and surgery is required
what is the pathogenesis of hip luxation?
usually traumatic (RTA, fall)
what is the aetiology of hip luxation?
can be seen spontaneously in dogs with hip dysplasia
how is the gait altered in dogs with hip luxation?
sudden onset lameness
stifle out, hock in and leg adducted
dislocated leg appears shorter
which direction does hip luxation usually occur in?
craniodorsally
what are the clinical signs of hip luxation?
variable lameness/pain/crepitus
palpation of landmarks (greater trochanter in line with iliac crest/tuber ischii)
‘shorter’ limb length
thumb displacement test
how do you carry out the thumb displacement test for hip luxation?
place thumb between tuber ischii and greater trochanter - with dislocation, thumb will stay in notch with manipulation
why are radiographs/CT scans essential for diagnosis of hip luxation?
physical examination and clinical signs can be complicated by the presence of fractures of the pelvis and proximal femur
which factors affect the method of treatment for hip luxation?
presence of pre-existing disease (hip dysplasia)
duration of luxation
concurrent orthopaedic injuries
what are the management options for hip luxation?
closed reduction +/- stabilisation
open reduction
salvage surgery
what is closed reduction of hip luxation?
manual manipulation of the femoral head back into the acetabulum
when should closed reduction of hip luxation never be attempted?
if:
acetabular/femoral head fractures
chronic luxations/hip dysplasia
other injuries e.g. pelvic fractures preventing reduction
evaluation of the cartilage is needed
what is the technique for closed reduction of hip luxation?
–Animal anaesthetised
–Assistant needed to hold on to dog or may be pulled off table
–Extend, adduct and externally rotate limb to lift femoral head over dorsal acetabular rim
–Then abduct and internally rotate to sit femoral head into the acetabulum
–Confirm reduction with two orthogonal xrays
–Ehmer sling or cage rest post reduction
what are the methods involved in open reduction of hip luxation?
iliofemoral suture (common) toggle transarticular pin prosthetic capsular repair primary capsular repair
what is the prognosis for hip luxation?
good in 75% of cases
OA will form eventually
recurrent dislocation possible
what is patella luxation?
displacement of the patella from its groove in the distal femur
which way does the patella usually luxate?
medially
is patella luxation usually unilateral or bilateral?
bilateral
which animals are more likely to develop patella luxation?
common in small breed dogs
lateral luxation in large breed dogs
can occur in cats
what is the aetiology of patella luxation?
most cases are developmental and appear when young - possibly hereditary
occasionally atraumatic
how is the gait altered with patella luxation?
may avoid flexing or extending the stifle
appears to walk in ‘cowboy’ stance with stifles flexed and a wide based stance
what is usually found with clinical examination of patella luxation?
stifle discomfort
patella clicks on manipulation of stifle
stifle in extension - look for patella laxity
what is a grade I patella luxation?
Patella normally within the groove
Returns spontaneously when luxated manually
what is a grade II patella luxation?
Patella normally within the groove
Can be luxated and will remain so when released
what is grade III patella luxation?
Patella normally outside the groove
Can be manipulated back into the groove
what is grade IV patella luxation?
Patella normally outside the groove
Cannot be reduced by manipulation
what is the most common grade of patella luxation?
grade II
how is patella luxation treated?
tibial tuberosity transposition - realigns the tibial tuberosity and the quadriceps line of pull with the groove
what is involved in post-op care for patella luxation?
consider support dressing
multimodal analgesia
strict rest initially, gradual increase in exercise after 6 weeks
what is the prognosis for patella luxation?
deteriorates with increasing grade of luxation
90-95% success in small dogs
significantly higher risk of failure in larger dogs (>20kg)
what is the most common cause of hindlimb lameness in dogs?
cranial cruciate ligament disease (CCLD)
what are the functions of the cranial cruciate ligament?
limit cranial drawer
limit hyperextension
limit internal rotation
what are the causes of cranial cruciate ligament disease?
degeneration of the ligament (common)
inflammatory arthropathy
growth abnormality (tibial plateau angle)
major trauma (uncommon)
which dogs are most likely to develop cranial cruciate ligament disease?
young (6m-3y)
large breeds
what percentage of cranial cruciate ligament disease occurs bilaterally?
30-50%
what are the 2 bands of the cranial cruciate ligament?
caudolateral - only tight in extension
craniomedial - always tight
which band of the cranial cruciate ligament is more susceptible to partial tears?
craniomedial band
how is cranial cruciate ligament disease diagnosed?
gait analysis
physical examination - stifle pain, effusion, crepitus, medial buttress, instability
what are the 2 tests used to assess instability in cranial cruciate ligament disease?
cranial drawer test
tibial thrust
what are the drawbacks of the cranial drawer test?
can be painful
can be resisted in the conscious animal
what is the tibial thrust test?
applying pressure at the level of the hock in order to test for tibial movement against the femur
how is cranial cruciate ligament disease diagnosed?
straightforward cases - signalment, instability tests, painful stifle, effusion
how are problem cases of cranial cruciate ligament disease diagnosed?
if not DJD on radiograph or effusion
possibly partial rupture but other arthropathies are possible
consider arthrocentesis
how is cranial cruciate ligament disease treated?
conservative treatment
surgical - intra/extra-articular replacements (fabello-tibial sutures)
OR corrective osteotomy (TPLO)
what are the post-op considerations for cranial cruciate ligament disease?
opioids for 24-48 hours, NSAIDs for 10-14 days
physiotherapy is important and beneficial to recovery
must make owners aware that surgery is not a cure, only slows progression of arthritis - joint will never be normal again
what is the prognosis for cranial cruciate ligament disease?
complication and success rates similar between techniques
most effective is osteotomy procedures
‘over the top’ is least effective
full recovery can take several months
how often does cranial cruciate ligament disease also result in meniscal tearing?
50%
how are meniscal tears treated?
must perform arthrotomy during surgery - debride torn portion and leave unaffected meniscus
which meniscus usually tears with cranial cruciate ligament disease?
usually medial meniscus
