Ortho - Hips, elbows and cruciates Flashcards
what is hip dysplasia?
a common inherited developmental disease characterised by laxity of the hip joint
are hips lax from birth?
no, puppies are born normal - laxity apparent from 4-5 months
which animals are commonly affected by hip dysplasia?
most commonly large and giant breed dogs
also affects small breeds and cats
when are the earliest signs of hip laxity usually seen?
4-5 months
what is the usual signalment for hip dysplasia?
4-12 months at first presentation
second phase affects adults - present with arthritis secondary to hip dysplasia - no laxity
what is the usual history associated with hip dysplasia?
hindlimb stiffness and difficulty mobilising, affecting both legs, bunny hopping, adducted hindlimbs
what can we see on gait analysis which is characteristic of hip dysplasia?
short stride on hindlimbs
lateral sway to avoid full stride - uses back
bunny hopping
adducted hindlimbs
what might we see upon orthopaedic examination of a patient with hip dysplasia?
muscle atrophy (quadriceps)
pain on hip extension
crepitus
clunking
what radiographic views are useful in diagnosing hip dysplasia?
v/d extended
frog leg
lateral pelvis
which manipulation tests can be used to test for hip dysplasia?
ortolani test
Bardens hip lift test
in which cases is the ortolani test not useful?
older dogs with arthritis
negative in cases of dislocation - will be unable to relocate joint
how is the Bardens hip lift test performed?
patient in lateral
hip is levered out of acetabulum to see how much ‘bounce’ is achieved
can the Bardens hip lift test be done on a conscious patient?
no - patient must be heavily sedated/under GA - painful test
what is classed as an abnormal Bardens hip lift result?
> 0.5cm
what are the available treatment options for hip dysplasia?
conservative managament
myotomies
growth plate fusion
osteotomies
THR
FHNE
what type of growth plate fusion is carried out on patients with hip dysplasia?
juvenile pubic symphysiodesis
which patients are suitable for growth plate fusion/osteotomy?
young patients with early diagnosis
what is involved in conservative management of hip dysplasia?
restricting exercise to lead-only - short regular walks, no off-lead
hydrotherapy
controlling food intake to restrict weight and slow down growth
judicious use of NSAIDs and other medication
can conservative management improve degree of subluxation?
not shown to improve - remains same or worse
what is juvenile pubic symphysiodesis?
iatrogenic closure of the pubic symphysis
how is juvenile pubic symphysiodesis achieved?
electrocautery to create thermal necrosis
what does juvenile pubic symphysiodesis result in?
growth of acetabulum which increases dorsal cover of the femoral head
why is juvenile pubic symphysiodesis rarely done?
must be done when patient is very young, during early growth phase - rarely identified this early
why is it important to neuter dogs who have had juvenile pubic symphysiodesis?
to ensure they are not bred from to avoid passing the condition on
when should a triple/double pelvic osteotomy be performed?
by 6-7 months, no DJD present
why is a triple/double pelvic osteotomy not commonly performed?
most cases are identified too late for this approach
how do we identify patients who are suitable for a triple/double pelvic osteotomy?
good clunk on ortolani test
what is the aim of a triple/double pelvic osteotomy?
increase dorsal cover of the femoral head
how is a triple/double pelvic osteotomy performed?
cutting into bone of ilium, pubis and ischium and rotating bone round to improve dorsal cover of the femoral head
what are the possible complications of a triple/double pelvic osteotomy?
screw pullout
screw breakage
- do not usually require correction
what is the success rate of triple/double pelvic osteotomy?
90% success
does a triple/double pelvic osteotomy prevent arthritis?
no - may still require salvage surgery later on
what type of procedure is a FHNE?
salvage procedure - pseudoarthrosis
what is a pseudoarthrosis?
fills in with bone and fibrous tissue
how can we improve outcome after a FHNE?
encourage exercise after surgery - outcome improved by good post-op rehabilitation programme
what is denervation?
removal of the nerves on the dorsal acetabulum - not commonly done
when might denervation be carried out?
with cost constraints - cheaper and provides pain relief
what are the aims of a THR?
pain relief
return of high level function
what are the indications for THR?
end-stage hip arthritis
hip dysplasia (younger dogs)
what are the 2 main types of prosthesis in THR?
acetabular prosthesis
femoral prosthesis
what are the overall steps of the surgical procedure for a THR?
femoral head excision
ream acetabulum and femur
cement acetabulum and femur
place “femoral head”
reduce hip
take bacterial swab
suture joint capsule, routine closure
which approach is used during a THR?
craniolateral approach
what does it mean to ‘ream’?
remove cartilage
why should the joint capsule be sutured as part of a THR?
helps reduce the chance of dislocation following surgery
why should we take a bacterial swab during a THR?
to ensure no contamination of the site during surgery
what are we assessing on the immediate post-op radiographs after a THR?
positioning of femoral stem and acetabulum
cement fill - no fissures, leakage
what are we assessing on long-term radiographs after a THR?
position of femoral stem and acetabulum
periosteal reaction
cement/bone interface
when should post-op radiographs be taken for a THR?
immediately post-op and 6 weeks post-op
what are the possible complications after a THR?
fracture
loosening
dislocation
infection
subsidence
cement granuloma
neurological issue
what are the 2 main type of hip implant available?
cemented vs uncemented
which factors influence the type of THR performed?
surgeon preference, shape of femur/acetamulum, equipment available in practice
what is involved in post-op care after a THR?
cage
lead walks only
ehmer sling
hobbles
avoid slippery surfaces, avoid jumping
what occurs at the end of the post-op period?
re-examination and further radiographs taken - ensure no complications have occurred
how can loosening of the THR implant be seen on radiographs?
increased lucency between the bone and cement
how can infection of the THR implant be seen on radiograph?
periosteal reaction
what should occur is progress is satisfactory at the 6 week check?
gradual return to normal exercise over the next few months
what is the most common cause of forelimb lameness in dogs?
developmental elbow disease (DED)
what type of abnormalities can be involved in developmental elbow disease?
fragmented medial coronoid process of the ulna
osteochondritis dissecans
joint incongruity
ununited anconeal process of ulna
why does joint incongruity occur in the elbow?
asynchronous growth of radius and ulna
what does developmental elbow disease result in?
varying amounts of elbow osteoarthritis
can different abnormalities of developmental elbow disease occur at the same time?
yes
what is the common signalment for elbow dysplasia?
large breeds e.g. labradors, rottweilers, retrievers, BMDs
6 months and older (at presentation)
males over-represented - females also affected
when might a dog present older with developmental elbow disease?
if have arthritis secondary to elbow disease
what are the signs of elbow dysplasia?
lameness
elbow effusion if severe
decreased ROM
pain on extremes of flexion and extension
what is the common history for a dog with elbow dysplasia?
low grade mild lameness, bilateral
which radiography views are helpful in the diagnosis of DED?
cranio-caudal, medio-lateral and flexed lateral views of the elbow
which radiographic features are indicative of DJD in elbow dysplasia?
sclerosis of the ulnar notch
flattened or blurred coronoid process
increased humeroradial joint space
what is the neutral lateral view of the elbow useful for?
looking for incongruity
what is the fully flexed mediolateral view of the elbow useful for?
looking at dorsal osteophytes on the anconeus
what is the cranio-caudal view of the elbow useful for?
looking for osteochondritis dissecans
what is the craniolateral-caudomedial oblique view of the elbow useful for?
looking for fragmentation of the coronoid process (FCP)
what is the distomedial-proximolateral oblique view of the elbow useful for?
viewing the coronoid process (looking for FCP)
what is the gold standard method for diagnosis of fragmentation of the coronoid process in the elbow?
CT scan
what is the signalment for ununited anconeal process?
large breed dogs, esp. german shepherds
at what age should the anconeal process fuse to the proximal ulna?
4-5 months
what happens if the anconeal process doesn’t fuse to the proximal ulna?
elbow stability is compromised and osteoarthritis ensues
how does ununited anconeal process occur?
short ulna compared to radius - growth proceeds and creates a shear separating the anconeal process from the ulna
how is ununited anconeal process diagnosed?
fully flexed mediolateral radiographs or CT scan
what are the treatment options for ununited anconeal process?
conservative treatment
removal of anconeal process (older dogs)
proximal dynamic ulna osteotomy
lag screw fixation (reattachment)
what determines treatment options for ununited anconeal process?
age and displacement of the anconeus
what happens during a proximal dynamic ulnar osteotomy?
cutting of the ulna - allows lengthening of the ulna as the radius grows and removes the shear stress of the anconeal process, allow it to reunite with the ulnar metaphysis
when might fragment removal for ununited anconeal process be performed?
not usually recommended unless the fragment is very displaced or abnormal
usually done in older dogs with OA
what is an ulnar ostectomy?
removal of small part of the ulna
how can short radius syndrome be improved?
dynamic partial ulnar ostectomy - allows improved humeroradial contact
what is the signalment for osteochondrosis dissecans?
medium-sized and larger breeds
presentation around 6 months, sometimes younger
which part of the elbow is usually affected be osteochondritis dissecans?
medial humeral condyle
what is the common history for a osteochondritis dissecans case?
forelimb lameness since 5-6 months age
can have some improvement on NSAIDs
what is osteochondritis dissecans?
cartilage flap on the medial condyle of the elbow
what is the presenting sign of osteochondritis dissecans?
forelimb lameness and effusion
how can osteochondritis dissecans be seen on radiographs?
craniocaudal and flexed mediolateral views
how is osteochondritis dissecans usually seen on radiographs?
flattening of medial humeral condyle on CC view - subchondral bone defect
what are the treatment options for osteochondritis dissecans?
conservative treatment - restricted exercise, NSAIDs
surgery - arthrotomy/arthroscopy and debridement for flap removal
abrasion arthroplasty or microfracture of the subchondral bone (stimulating bone to heal)
what is treatment of osteochondritis dissecans dependent on?
severity of lameness and size of lesion
what is the most common elbow pathology diagnosed in dogs with elbow dysplasia?
fragmented medial coronoid process
where is fragmentation most commonly seen with fragmented medial coronoid process?
craniolateral aspect of the medial coronoid process of the ulna, adjacent to the radial head
how do bone fragments look under arthroscopy in fragmented medial coronoid process?
bone fragments often dead and yellow in appearance compared to well-vascularised red-coloured live bone
what are the possible causes of fragmented medial coronoid process?
shallow ulnar notch
short ulna during growth
what is the signalment for fragmented medial coronoid process?
6-10 months old
medium-large breed dogs (some small)
often bilateral
how is fragmented medial coronoid process diangosed?
x-ray/CT
how is fragmented medial coronoid process treated?
arthroscopic debridement
medical management of arthritis well established already
what do dogs with elbow dysplasia go on to develop?
osteoarthritis
what is involved in medical management of OA?
NSAIDs, weight loss, hydrotherapy, physiotherapy
how can severity of OA be evaluated?
arthroscopy
what is the goal of surgical OA treatment (arthroscopically)?
debridement of necrotic cartilage
removal of sclerotic bone
neovascularisation
recruitment of pluripotential mesenchymal cells
how can OA be surgically treated?
removal of loose cartilage and subchondral bone via abrasion arthroplasty
stimulation of healing bone using microfracture - induced stem cell healing of hyaline cartilage
why is long bone osteotomy for DED often performed on the medial side?
dogs with DED often have more problems on the medial aspect of the the joint than the lateral (medial compartment disease)
what is the aim of a long bone osteotomy?
decrease medial compartment load
what is the aim of a sliding humeral osteotomy?
transfer weightbearing from the medial aspect of the joint to the lateral aspect
what is the purpose of a proximal abducting ulna osteotomy?
transfer weightbearing from the medial aspect of the joint to the lateral aspect
what are the surgical options for long bone osteotomy?
sliding humeral osteotomy
proximal abducting ulnar osteotomy
proximal dynamic ulnar osteotomy
what is proximal dynamic ulna osteotomy performed for?
medial compartment disease
radioulnar icongruence
ununited anconeal process
why is elbow replacement not commonly performed in dogs?
complications are common, often require additional surgery and ultimately may lead to arthrodesis or amputation
when might an elbow arthrodesis be performed?
final salvage procedure for end-stage painful joint
what are the indications for arthroscopy?
exploration of joint for diagnosis
removal of loose bodies
topical treatment for OA - microfracture and abrasion arthroplasty
debridement and lavage
assisted joint stabilisation or fracture repair
what are the advantages of arthroscopy compared to arthrotomy?
decreased morbidity
more rapid recovery
decreased complications and improved outcomes
decreased surgery/GA/hospitalisation times
what are the disadvantages of arthroscopy?
high skill level required, long learning curve
expensive equipment
increased cost to client
which diameter arthroscope is used for elbows?
1.9, 2.4 or 2.7mm
what is the lens angle for an elbow arthroscope?
30 degrees - allows for wider view
what is the normal working length for an elbow arthroscope?
short 8.5cm or long 13cm
what does the cranial cruciate ligament do?
resists stifle extension
resists internal rotation
prevents tibia moving cranially
which animals are affected by cranial cruciate ligament rupture?
dogs, rarely cats
overweight females, neutered, middle aged
via what 3 ways can cruciate ligament rupture occur?
traumatic
degenerative
inflammation
how does traumatic cranial cruciate rupture occur?
can be seen after heavy fall, catching foot at awkward angle, RTA
how does degenerative cranial cruciate rupture occur?
rupture occurs secondary to minimal trauma through ligaments that how evidence of degeneration and ageing
how does inflammatory cranial cruciate rupture occur?
occurs in joints with evidence of inflammation e.g. rheumatoid arthritis
how can we diagnose cranial cruciate ligament rupture?
cranial draw test
tibial compression test
radiographs - mediolateral and cr/cd views
what can be seen on radiographs where cranial cruciate rupture has occurred?
joint effusion - seen as compression of the parapatellar fat pad
chronic - evidence of OA/DJD seen as osteophyte formation on various parts of stifle
how can we surgically treat cranial cruciate ligament rupture?
intra-articular replacement of ligament
extra-articular replicate function of ligament
combination of above
alteration of joint angles
what is involved in conservative management of cranial cruciate ligament disease?
strict rest for 6-8 weeks
which animals are more suited to conservative management for cranial cruciate ligament disease?
dogs and cats <15kg
which type of stifle lesion does not do well with conservative management?
those with meniscal tears
what happens if there is not improvement from conservative management for cranial cruciate ligament disease?
surgery is indicated if no improvement after 6-8 weeks of rest
what are the principles of surgical therapy for cranial cruciate ligament disease?
confirm diagnosis via exploratory arthrotomy
debridement of ruptured ligament
check and remove torn pieces of menisci
stabilisation of the stifle joint
give a brief overview of the lateral (DeAngelis) suture technique for cranial cruciate ligament disease
suture is placed medial to the lateral femorofabella ligament, under the patellar ligament and through a small tunnel in the tibial tuberosity
progressively increase tension and check for cranial drawer
which suture material should be chosen for lateral suture technique?
non-absorbable, monofilament, very strong
large gauge nylon in smaller patients (ethilon/prolene)
fishing leader line (monofilament nylon) in larger patients
how is the suture secured in the lateral suture technique?
metal tube and crimp fastener
how is the fascia lata repaired during lateral suture?
modified mayo mattress suture
what are the possible complications of lateral suture?
suture failure - breakage, stretching, pull through crimp
instability
infection
meniscal tear
anchor pull-out
what is the advantage of a lateral suture technique?
common complications are rarely severe
how does the femur move in relation to the tibia when the cranial cruciate ligament is ruptured?
femur slides caudally down the slope of the tibial plateau - tibial thrust is cranial
what is the average angle of the tibial plateau?
24 degrees
what are the general concepts involved in TPLO surgery?
medial arthrotomy to inspect cruciate and menisci
medial approach to proximal tibia - circular saw used to cut proximal tibia
cut part of tibia rotated a predetermined number of degrees to increase tibia plateau to 5-7 degrees
bone stabilised in new position with TPLO plate
why does the tibia move when the cranial cruciate ligament ruptures?
it is the only passive restraint to ‘slippage’ against weight and muscular propulsive forces
what type of technique is a TPLO?
joint mechanic altering technique
why are locking plates preferred over traditional plates for TPLO?
increased stability and better limb alignment
where is the TPLO plate positioned?
medial surface of the tibia
which type of saw is used for a TPLO?
oscillating
what are possible complications of TPLO?
fibula fracture
peroneal nerve damage
popliteal artery trauma
tibial tuberosity avulsion fracture
patella ligament desmitis
pivot shift
osteomyelitis
seroma formation
what is the prognosis with TPLO?
80% of patients return to soundness
what are some of the alternative techniques to TPLO?
cranial closing wedge/tibial wedge ostectomy
tibial tuberosity advancement
modified maquet technique
triple tibial osteotomy
what do all the surgical procedures for cranial cruciate rupture have in common?
work on a similar principle of trying to eliminate the tibial thrust that occurs after CCL rupture
what is involved in post-op care after cruciate surgery?
confinement and minimal exercise for 4-6 weeks
carefully controlled and gradual increase in exercise for the following 6-10 weeks
physiotherapy and hydrotherapy
what are menisci?
‘C’ shaped pads of fibrocartilage in the stifle joint
what is the function of menisci in the stifle joint?
shock absorption and aid in fluid shift and nutrition in the joint
which meniscus is more commonly damaged?
medial meniscus
why might the medial meniscus be more commonly damaged?
possible due to its attachment to the medial collateral ligament - means it is less mobile and more prone to crushing and grinding
what usually goes alongside meniscal injuries?
usually seen subsequent to cranial cruciate disease - rarely in isolation
how might we detect meniscal injury?
may have a palpable or audible click on stifle manipulation (not reliable)
stifle is painful
how can meniscal injury be confirmed?
careful inspection during stifle arthrotomy/arthroscopy using a stifle/Senn retractor or Hohmann retractor and good light
what types of meniscal injuries are possible?
bucket handle tears
detachment of the caudal horn
fibrillation
what is involved in treatment for meniscal injuries?
probe with meniscal probe
torn portion removed using meniscal forceps and sharp narrow scalpel blade
why should owners be advised to carefully observe their animal after cruciate surgery?
meniscal tears can occur late after cruciate surgery (months/years)
why do dogs with meniscal tears have a poorer prognosis than those without?
they are more prone to developing DJD and post-cruciate stiffness/lameness long-term
