Small Animal Orthopedic Diseases Flashcards
What structures can you palpate in the canine shoulder
Gretaer tubercle (lateral)
Acromion
What are the diagnostics to do once you locate a shoudler lamenesss in a dog
Exam: ROM/Pain, Abduction ange = muscle atrophy
Muscle pain = myopathy
Radiographs: OCD, arthritis, muscle calcificaition
Ultrasound: Biceps, Supraspinatus, MGHL/ Sub-scapularis
other: MRI, arthroscopy, CT, joint fluid analysis
What shoulder abnormalities can you identify on radiographs
OCD
Arthritis
Muscle calcification
if muscle problem w/o calcification then it is a muscle issue and do ultrasound
What shoulder abnormalities can you identify on radiographs
Biceps
Supraspinatus
MGHL/Sub-scapularis
When should you do joint fluid analysis of the canine shoulder
Septic arthritis (rare) or immune mediated diseases
What are the two joints in the dog where you need to evaluate shoulder abduction
Shoulder
Hip
When doing a physical exam on the dog’s shoulder what should you do
1) ROM and hyperextension/flexion
2) Shoulder abduction
3) Drawer motion
4) Individual muscles/tendons:
Passive flexibility (ie biceps test)
Pain
Atrophy
What are differentials for shoulder muscle atrophy in a dog
Typically due to lameness (ie arthritis)
but need to rule out other differentials
ie. Brachial plexus tumor or neurological issue
In dogs, You cannot extend the shoulder without _______ *
extending the elbow
but you can extend the elbow without extending the shoulder
thats how you differentiate the joints from each other
What might be occuring if a dog has pain on shoulder flexion
1) Shoulder problem
2) Supraspinatus issue
What might be occurring if a dog has pain upon shoulder extension
1) Shoulder problem
2) Elbow problem
you cannot extend the shoulder without extending the elbow
What causes shoulder OCD in dogs
genetics
nutrition (excessive Ca, high calorie/protein)
Shoulder OCD in dogs typically affects
large and giant breeds (juveniles)
Is lameness due to OCD in dogs typically unilateral or bilateral in dogs
lameness is typically unilateral but lesions can be bilateral
lameness may wax and wane or even disappear
What is the risk of having dogs with OCD lameness run around to fix the lameness
it may cause the OCD fragment to dislodge and fix the problem in short time but over time it will incorporate and cause secondary biceps tendonopathy (fragment in biceps groove) or synovial osteochondroma formation
What are differential diagnoses for dogs with shoulder OCD
Elbow dysplasia and panosteitis (juveniles)
How do you diagnose shoulder OCD in dogs
take multiple radiograph oblique views of both legs
pain on extension, FLEXION, and rotation of shoulder
CT is ideal but not required if rads are obvious
Arthrogram if rotated X-rays not helpful and CT not available
Dogs with shoulder OCD typically have pain when
their shoulder is flexed because that where flap rubs on scapula, however lots of dogs are also painful on flexion and rotation
How do you treat shoulder OCD in dogs
Surgically: Osteochondroplasty to remove the flap
or
Osteochondral Autograft Transfer System (OATS)
prognosis with surgically - excellent for caudal lesions
good for caudo-central lesions
follow up with OA preventative management
a surgical procedure to remove an osteochondral flap
osteochondroplasty
Out of all the OCD joint sites in dogs, what has the best prognosis
Shoulder
excellent prognosis for caudal lesions
good for caudo-central lesion
When might people consider Osteochondral Autograft Transfer System (OATS) for the treatment of shoulder OCD in dogs as opposed to osteochondroplasty?
If the lesion is caudo-central as opposed to caudal but this is pretty aggressive and not done often
pathology of the medial compartment/stabilizers of the shoulder in dogs
-Medial glenoid-humeral ligament
-Subscapularis
medial shoulder instability (syndrome)
What two structures are imparted with medial shoulder instability in dogs
1) Medial glenoid humeral ligament
2) Subscapularis
What causes medial shoulder instability
unknown but thought to be to repetitive microtrauma/overstretching as it is associated with adult athlete dogs: agility, flyball, hunting, etc.
What is the typical signalment of dogs with medial shoulder instability
adult athlete dogs: agility, flyball, hunting, etc.
What are the clinical signs of dogs with medial shoulder instability
-Mild to moderate shoulder instability
-Decreased performance
-Change in gait (stepping with 2 feet vs one foot when weaving through poles- athletic dogs)
How do you diagnose medial shoulder instability in dogs
1) Painful shoulder abduction (nonsedated)
2) Radiographs- mild OA or normal
3) Subjectively increased abduction angle when elbow and shoulder are extended
should be about 32.6 degrees
compare left and right
4) Arthroscopy
5) MRI
6) Ultrasound
7) Compare muscle atrophy to the opposite leg
How do you measure abduction angle seen with medial shoulder instability
1) Have the shoulder and elbow in extension
2) Abduct the leg (sedation)
3) Center the goniometer on shoulder joint
4) Line of humerus and parallel to scapular spine
5) Measure angle at goniometer
Normal is 32.6 +/- 2
make sure to compare left and right
What could give you a falsely positive abduction angle in a dog
not having the shoulder and elbow in extension
this could give you a false positive of 60 degrees
What is a normal shoulder abduction angle
Around 30 degrees
Do dogs need to be sedated to measure abduction angle to diagnose medial shoulder instability
YES
You notice an increase shoulder abduction angle in a dog, how do you confirm the diagnosis of medial shoulder instability
1) Arthroscopy: Intra-articular components of medial genoid humeral ligament and subscapularis
2) MRI: all inta-and extraarticular structures besides cartilage
3) Ultrasound: technically challenging but done a lot, needs a really good user
What are the grades of medial shoulder instability in dogs?
1: Abduction angle of 30-39. Arthroscopic findings of synovitis but no obvious MGHL/subscapularis pathology besides laxity/ joint capsule tearing
2: Abduction angle of 40-55. Arthroscopic findings of synovitis, fraying to partial disruption of of subscapularis tendon and/or MGHL
3: Abduction angle of >55 degrees
Arthroscopic findings of complete tearing of subscapularis and MGHL and subluxation of humeral head
4: Complete shoulder luxation, disruption of two structures, seen radiographically
Complete shoulder luxation, disruption of two structures, seen radiographically
Grade 4 Medial Shoulder Instability- Syndrome
Abduction angle of >55 degrees
Arthroscopic findings of complete tearing of subscapularis and MGHL and subluxation of humeral head
Grade 3 Medial Shoulder Instability- Syndrome
Abduction angle of 40-55. Arthroscopic findings of synovitis, fraying to partial disruption of of subscapularis tendon and/or MGHL
Grade 2 Medial Shoulder Instability- Syndrome
Abduction angle of 30-39. Arthroscopic findings of synovitis but no obvious MGHL/subscapularis pathology besides laxity/ joint capsule tearing
Grade 1 Medial Shoulder Instability- Syndrome
treat with rehab (hobbles), shockwave, PRP
What are the surgical options of medial shoulder instability (Grade 3-4)
1) Radiofrequency shrinkage: heat probe to do thermal oblate to shrink the tissues, not commonly performed over damage to cartilage
2) Prosthetic ligament reconstruction: attach on each side of joint, bone anchor and artificial ligament to replace the torn ligament
3) Tendon transposition (biceps)
4) Post-OP: hobbles/rehab
IS IT SURGERY OR JUST POST OP REHAB
How do you treat mild/moderate medial shoulder instability in dogs (Grades 1-2)
Rehab (Hobbles, Theraband, exercises, shockwave, PRP)
you notice metal opaque objects on the humeral head and scapula, what was likely being treated
Medial Shoulder Syndrome
Medial Shoulder Instability
Traumatic Shoulder Luxation
a term that implies both degeneration and inflammation of the tendon
tendinopathy
What causes biceps or supraspinatus tendinopathy
can be due to degeneration +/- inflammation
Hypovascular areas at origin/insertion
hypoxia leads to fibrocartilaginous transformation of the tendon
What causes fibrocartilaginous transformation of the tendon seen in tendinopathies
hypoxia at the hypovascular areas of origin/insertion
What are the different types of tendinopathies
Primary: tendinopathies die to repetitive microtrauma (large/active dogs), cause by trauma/overuse
Secondary: irriation/inflammation due to other joint diseases like OCD, supraspinatus, MSI
commonly seen in biceps tendinopathy
What is the origin of the biceps brachii muscle
Supraglenoid tubercle
What is the insertion of the biceps brachii muscle
Radial and ulnar tuberosities
What is the origin and insertion of the biceps brachii
Supraglenoid tubercle
Radial and ulnar tuberosities
What is the origin of the supraspinatus muscle
Supraspinous fossa
What is the insertion of the supraspinatus muscle
greater tubercle of the humerus
What is origin and insertion of the supraspinatus muscle
Origin: Supraspinous fossa
Insertion: Greater tubercle of the humerus
What is the typical presentation of biceps/supraspinatus tendinopathies
middle-aged, medium/large breed athletic dogs
History: progressive lameness (Nonweight bearing with partial acute avulsion), exacerbated with exercise
What are your differentials for dogs with biceps/ supraspinatus tendinopathies
ED/DJD - take rads +/- CT for adult onset
OA- take rads of the proximal humerus to rule out osteosarcoma
Neuro (including brachial plexus tumor)- check reflexes, CP, anisocoria
When a dog has biceps/supraspinatus tendinopathies, how do you rule out neurological disease
Check reflexes
Central proprioception
Lack of Anisocoria
How do you test a dog with biceps/supraspinatus tendinopathies
Palpation
Biceps: Pain when extend elbow, flex shoulder
Supraspinatus: Pain on palpation of insertion on greater tubercle, shoulder flexion while elbow flexed
You notice pain when extending the elbow and shoulder, what do you do next
Isolated hyperextension of the elbow, if still painful then it is likely the elbow
How do you test for supraspinatus tendinopathy
1) Painful palpation of insertion of greater tubercle
2) Pain when shoulder flexed, elbow flexed
How do you test for biceps tendinopathy
Painful when extend elbow, flex shoulder
How do you confirm diagnosis of a dog with biceps/supraspinatus tendinopathies
Radiographs (both)- only for calcifying tendinopathies
US, MRI (both)
Arthrogram (biceps only)
Arthroscopy (Biceps intra-articular)
On radiographs, how do you distinguish biceps from supraspinatus tendinopathies
Supraspinatus: fragments along the greater tubercle (more cranial)
Biceps brachii: fragment along the groove
Tendionpathies are only distinguishable on radiograph if
they are calcified
Arthrograms can only distinguish biceps or supraspinatus tendinopathies
Biceps - the only one that is in the joint
Supraspinatus is extra-articular
What is the big question when finding calcification of the biceps or supraspinatus tendons
it could be incidental or a reason for the lameness
do joint blocks for intra-articular disease (may help)
What radiograph views are helpful in identifying calcifying biceps/ supraspinatus tendinopathies
1) Lateral view
2) Craniocaudal view
3) Skyline view (intertibercular groove)
T/F: Ultrasound can only pick up calcifying biceps/ supraspinatus tendinopathies
False- can detect calcified or non-calcified tendinopathies
Dynamic - can detect adhesions of the tendon (MRI and Rads cant do this)
How do you treat Biceps tendinopathies in dogs
1) PT/Rehab
2) Medical: 5mg Triamaicnolone (shorter duration and safer than Depo) because it is intra-articular
3) Surgical (not really needed): Tenodesis (open), Tenotomy (Scope/Ultrasound)
What shoulder tendon is intra-articular
Biceps
that is why you can treat Biceps tendinopathies with 5mg Triamaicnolone
Tenodesis for biceps tendinopathy treatment
cutting tendon at origin and then release at inch and then reattach it at proximal humerus
this is different from tenotomy, where it is just cut and reattaches by itself
T/F: biceps tendinopathy is best treated with surgical management
False- it is not really done, patients respond well to PT/Rehab
How do you treat Supraspinatus tendinopathy
1) PT/Rehab
2) Medical: shock wave, PRP
3) Surgical: tendon resection, release of transverse humeral ligament, release incisions in supraspinatus
Biceps/Supraspinatus diagnosis and treatment (broad)
Diagnose with PE, X-rays, Ultrasound
Targeted treatment: Rehab/ ESWT/ TA/PRP
If no significant improvement: Scope, MRI to reach definitive diagnose and release/excision sx
What structures are important to evaluate the positioning of hip radiographs
Ilial wing
Obturator foramen
T/F: OCD lesions can be seen in the hip joint
False- OCD lesions do not exist in the hip
What is seen well in a lateral pelvic radiograph
the lumbosacral joint (L7-S1)
What is a good radiograph view to see the lumbosacral joint
lateral projection
Unlike the elbow, the hip joint is an unstable joint. What are the stabilizers of the hip joint?
1) Normal congruency (femoral head and acetabulum)
2) Joint capsule and joint fluid (hydrostatic pressure)
3) Round ligament
4) Surrounding musculature
-Gluteals/Pectineus/ Adductor
Small pelvic association (mm. obturator internus, gemelli, obturator externus, and quadratus femoris)
Why do you not want to tap a joint if there might be instability
because you are introducing air and getting rid of the hydrostatic pressure, making it less stable
What is the function of the gluteal muscles?
-Hip extension
-Hip abduction
-Medial rotation of hip joint
-Hip stability
What is the origin and insertion of the pectineus muscles
O: ilio-pubic eminence
I: Distal femur
What is the function of the pectineus muscles
-Adduction of thigh (together with adductor)
-Hip stability
What muscles provide stabilizing to the hip joint
Gluteals
Pectineus
Adductor
The gluteal muscles (superficial, middle, and deep) all go from
ilium or tuber sacrale (superficial) to the greater trochanter or 3rd trochanter (superficial)
Origin and insertion of Gluteus medius and Deep
O: lateral ilium
I: greater trochanter
Origin and insertion of the gluteus superficalis
O: tuber sacrale
I: 3rd trochanter
Why does rehab work well for dogs with hip dysplasia
increasing the musculature around the hips is really important in providing stability to the joint
How do the gluteal and pectineus/adductor work together to co-contraction and stabilize the hip joint
Gluteals: Extend hip, abduct, and internally rotate
while the
Pectineus/Adductor: Extend hip, adducts, and externally rotates
reduces hip laxity
Contraction of what muscles subluxates the hip joint during the swing phase
Iliopsoas, rectus femoris, sartorius
Why do dogs with hip dysplasia have a shorter swing phase
because the shorter you make the swing phase, the less change of subluxation occurs
this is done by the iliopsoas, rectus femoris, and sartorius
What causes hip dysplasia in dogs
Genetically Predisposed animals
+
Environmental factors leading to enhanced expression of genetic weakness (e.g obesity)
What three characteristics make hip dysplasia definition
Hip laxity that results in hip subluxation that results in hip arthritis
What breeds are predisposed to hip dysplasia
-Golden retrievers
-German shephards
-Saint bernards
-Labradors
-Rottweilers
T/F: hip dysplasia commonly leads to animals being really unilateral lame
False
Are radiographs helpful in diagnosing hip dysplasia?
Not necessarily good for early stages but good at picking up arthritis
Palpation tests for hip dysplasia
Ortolani
Full pelvic limb extension
T/F: OFA is good at detecting hip dysplasia
False
Hip dysplasia has linear biphasic progression, what does this mean?
Juvenille: severe lameness and joint laxity then the joint tightens up w fibrosis but then you have adult dogs becoming lame from joint inflammation and periarticular fibrosis
What does the gait of a dog with hip dysplasia look like
short strided gait, not swing through with their limbs, tight skirt gait
In severe cases, you can see subluxation of the femoral head
What are the differential diagnoses for dogs with pain on hip extension
1) Hip dysplasia
2) CCLD
3) Neuro
4) Flexor muscle disease (stretching flexor muscles- could be iliopsoas)
If you notice a dog with pain on hip extension, what should you do next
Hip abduction and flexion
if yes- hip dysplasia
if no- then likely
1) Pain on lumbosacral palpation (neurologic)
2) Pain on stifle hyperextension (CCLD)
3) Flexor muscle pain (stretching individual muscles- ie iliopsoas myopathy)
What is painful in dogs with hip dysplasia
Hip extension
Hip abduction
Hip Flexion
T/F: dogs with hip dysplasia are painful in both hip flexion and extension
Tru e
You have a dog with pain on hip extension and lumbosacral palpation but no
no pain on abduction or lfexion.
what could be happening
Lumbosacral disease
perform further palpation and diagnostics of L4-S2 neurologic disease
T/F: dogs with CCLD are painful on hip extension
True- also extending the stifle
a test where the dog is in dorsal or lateral recumbency
one hand stabilizing pelvis
one hand pushing femur to subluxate hip via abduct
Ortolani
What indicates a positive ortolani test
Reduction and subluxation
What does a dog that is bunny hopping up the stairs indicate
Hip dysplasia or bilateral cruciate disease
Why do dogs with CCLD have their hind legs spread out when sitting
they do not want to flex their stifles
If they have a positive sit test what should you think
Cruciate disease
possibly hip dysplasia
How to take a OFA-like radiograph
Dog in dorsal
Hip joints extended
patella pointing straight up at ceiling
The femoral head should be covered by
> 50% of the acetabulum
How do you tell the pelvis is rotated when taking radiographs
look at the iliac wings
rotation makes the thinner winged side look better than the other side
Why is the femoral head thickened with hip dysplasia
joint capsule inflammed and pulled, ostephytes created, thickening the head
If the left hip is raised up from the table, what will the ilial body look like
it will be thinner
the femoral head will artificially appear further in the acetabulum
Thin is
up and in
How old does the dog need to be for OFA radiographs
> 2years of age
OFA is rad scored based on
consensus of 3 radiologist (OA, subluxation)
seven point ordinal grading system (excellent, good, fair, borderline, mild dysplasia, moderate dysplasia, severe dysplasai)
Bias as self-submission
What is the issue with OFA-like radiographs
when you extend the hips you create wind-up which makes the joint capsule tighter, making the hips look better
sometimes hip dysplasia is so bad you dont need other views
PENN HIP radiographs are better
T/F: OFA-like radiographs are a good start but not always diagnostic
True
What does the PennHip radiographs do
appartus that is put between the legs,
push in, trying to subluxate femur
What are the 3 radiograph views in PENNHIP radiographs
1) Compression view
2) Distraction view
3) OFA view
Measures “passive” not function laxity and places it into a distraction index that is breed specific
<0.3: no OA
>0.7: OA
0.3-0.7: greyzone
What does distraction index correlate with
DJD probability at >2 years
T/F: PennHIP radiographs is a mandatory submission
True
after submission you get OA risk category and breed average DI
Central 90% range of breed DI’s
If you get + ortolani, can you say it is positive if they arent sedated
YES
When does juvenile hip dysplasia occur
less than 5 months of age
If you get a - ortolani, can you say it is negative if they arent sedated
No- you must sedate muscle mass might be messing this up
Immature hip dysplasia occurs in dogs that are _________ old
5-14 months old
T/F: juvenille hip dysplasia abnormalities is hard to detect
True
Immature hip dysplasia diagnostics
owners usually notice abnormality
Ortolani-specify how it palpates
Radiographs: OFA-like frequent sufficient
PENN HIP only needed if no obvious subluxation
Adult hip dysplasia diagnostics
> 14 months old
abnormal gait
ortolani not present
radiographs- OFA-like alwyas sufficient
PennHIP not needed
When is the PennHIP not needed
when adult hip dysplasia
OFA-like always sufficient
Which is the most appropriate diagnostic tool to screen for hip arthritis in a 2-year-old dog?
OFA-like radiographs
What are the next step(s) for a 4-month-old puppy that presents to you with signs of hip dysplasia (short strided gait, pain on hip extension, flexion, and abduction), yet OFA-like radiographs are not showing evidence of HD? Please note that this owner wants you to only examine the area where you believe the problem is located.
PennHIP
Ortolani
dont do ortolani first before PENNHIP
What should you do first
-Ortolani
-PennHIP
PennHIP
ortolani can create gas bubbles
JPS can only be done in dogs that are
less than 5 months
What is the process of the juvenile pubic symphysiodesis sx
1) Cauterize pubic symphysis
2) Pubic symphysis growth halted
3) Remainder of pelvis grows normally
4) Increased coverage of femoral head
only for dogs less than 5 months
procedure to cauterize pubic growth plate leading to halted pubic symphysis growth, causing the plevis to grow normally and increased coverage of femoral head
juvenile pubic symphysiodesis
What might be able to be done for dogs with hip dysplasia that are 5-14 months old
Triple Pelvic osteotomy
may not be recommended
procedures that involve ilial osteotomy to increase the coverage of the femoral head
Triple Pelvic Osteotomy
Double Pelvic Osteotomy
only for dogs 6-12 months old
What are the indications for dogs to get Triple Pelvic Osteotomy
1) 6-12 months old
2) Clinical symptoms
3) No significant DJD
4) Adequate dorsal acetbaular rim (DAR)
What needs to be done if owners consider TPO sx
PennHIP
DAR view
What needs to be done if owners do not consider TPO sx
Medical management
Total Hip replacement when needed
What are the benefits of JPS over TPO
JRS: both hips, less (no complications), less invasive, cheaper, easier
only benefit of TPO is that it can be done from 6-12 months
What are the treatment options for hip dysplasia in adult dogs
1) Medical management: Omega-3 fatty acids, weight loss, Glucosamine Cs/UC-II, Exercise modification, NSAIDS, and other pain meds
2) Total hip replacement
3) Femoral head and neck “ex”
What are the two most important components of hip dysplasia medical management in adult dogs
Omega-3-fatty acids
Weight loss/control
What are the total hip replacement options
Cemeted: aspeptic loosening
Cementless: last longer-
Hybrid: combined cemented stem/cup with cementless cup/stem
Is cemented or cementless hip replacement more prome to aspectic loosening
Cemented
what are the 3 complications of total hip replacement
1) Femur fracture- older dogs with thinner cortices
2) Luxation- more common in cemented THR
3) Infection
long term: aspectic loosening or implant failure
a surgery to eliminate the bony contact (source of pain) between the acetabulum and femoral head
creates fibrous pseudoarthrosis
variable results
Femoral head and neck ostectomy/excision
Femoral head and neck ostectomy/excision is better in smaller or bigger dogs
smaller
Why is Femoral head and neck ostectomy/excision not advised in juvenile patients
-Increased risk of bone regrowth
-Can always FHO
-Can not total hip repacement after femoral head ostectomy
What do you do if you have a dog with femoral head or acetabular fracture
FHO
-need to be very aggressive with rehab and ROM exercise
-long term painmeds
Best treatment for 4 MONTHS OLD DOG WITH HD
JPS
Best treatment for 8 MONTHS OLD DOG WITH HD
TPO
Best treatment for 2 YEAR OLD DOG WITH HD
THR
Best treatment for 2 YEAR OLD DOG WITH CCLD
TPLO
What causes a true hip luxation
1) HBC
2) Non-traumatic (watch for these = different treatment)
Is hip luxation more common in dogs or cats
Dogs
What gait will you see with craniodorsal hip luxation
Adducted with externally rotated stifle
looks like limb length discrepancy
limb length discrepancy
What is the most common type of hip luxation
craniodorsal
What are the different types of hip luxations
1) craniodorsal (most common)
2) Caudo-dorsal
3)Caudo-ventral
What should you do if you are unsure if the hip is luxated
take a 2nd view
When a dog’s hip is caudo-ventral luxated, where will the head of the femur be on radiograph
in the obturator foramen area
What do you evaluate in a dog with hip luxation
Are there any fractures?
Does the dog have good hip conformation
these change treatment
closed reduction tx for hip luxation
when you pop the head of the femur back into its place to fix hip luxation
not an option if the dog has arthritic hips (instead do FHO or THR)
What do you do if the dog has hip luxation with arthritis hips
you cant do closed reduction
do FHO or THR
What should you do for patients with hip luxation
Treat the patient first
-At least chest rads, 50% incidence of other issues (abdominal, thoracic, orthopedic)
ASAP closed reduction but prior to sedation, evaluate the patienr, do if no arthritis
What do you do after doing closed reduction of dorsal hip luxation treatment?
If closed reduction is succuessful, keep on Ehmer sling for no longer than 10-14 days
DogLegg’s less soft tissue swelling
Follow-up
-Recheck after 2-3 days and confirm hip reduced via rads
-Exercise restriction
-Aggressive PT once hip stable
-Arthritis management
Ehmer sling
a sling used to externally rotate and abduct the dog’s leg
Only For dorsal luxations
keeps the dog’s hip more likely to stay in place after closed reduction
What do you do after doing closed reduction of ventral hip luxation treatment?
Hobbles for 14 days to prevent abduction
Follow-up
-Recheck after 2-3 days and confirm hip reduced via rads
-Exercise restriction
-Aggressive PT once hip stable
-Arthritis management
How do you manage closed reduction of dorsal hip luxation vs ventral hip luxation
Dorsal: Ehmer sling to externally rotate and abduct leg (10-14)
Ventral: Hobbles (10-14) to prevent abduction
Both: -Recheck after 2-3 days and confirm hip reduced via rads
-Exercise restriction
-Aggressive PT once hip stable
-Arthritis management
What do you do if closed reduction of hip luxation is unsuccessful
1) Open reduction and stabilization: only if good hip conformation, best chance for normal hip
2) FHO: salvage procedure esp for smaller dogs and cats or if financial restrictions prevent THR
3) THR: if poor hip conformation, especially in larger dogs, very expensive
Open reduction
Approach to hip
-Trochanteric osteotomy (better exposure)
-Craniolateral approach (less complication)
Surgical stabilization
-Capsulorrhapy: suture/tighten joint capsule
-Capsule augmentation- can support with bone anchors dorsally
-Toggle pin or tightrope- replaces round ligament
non-inflammatory, aspectic necrosis of the femoral head
legg calve perthes disease
what breeds is legg calve perthes disease common in
toy and terrier breeds
What is the typical singalment of legg calve perthes disease
toy and terrier breeds
3-13 months (usually 5-8 months)
T/F: legg calve perthes disease is always unilateral
false bilateral involvment 15% of time
How do you treat legg calve perthes disease
FHO
they do well
What happens concurrently to legg calve perthes disease
medial patellar luxation
Diffuse periosteal reaction around distal bones associated with thoracic/abdominal mass
hypertrophic osteopathy
What are other names for hypertrophic osteopathy
-pulmonary osteoarthropathy
-hypertrophic pulmonary osteoarthropathy
-hypertrophic pulmonary osteopathy
What is the typical signalment of hypertrophic osteopathy
age- any, related to underlying disease (neoplasia = usually older)
Breed- any
gender: either
What are the clinical signs of hypertrophic osteopathy
lethargy, anorexia, unwillingness to move and unspecific signs more common than lameness
swollen, painful distal extremities
How do you diagnose hypertrophic osteopathy
careful general exam (abdominal palpaition)
ultrasound, thoracic and abdominal radiographs
limb radiographs
What does hypertrophic osteopathy look like on radiograph
‘Pallisade formation’
-Bilaterally symmetric periosteal reaction
-Smooth/regular or rough/aggressive
-Soft tissue swelling
What causes hypertrophic osteopathy
Paraneoplastic or associated with other disease
1) Commonly Pulmonary neoplasia (primary or metastatic)
2) Any mass can induce it
-Thoracic (esophageal granuloma, embryonal rhabdomyosarcoma)
-Abdominal (liver neoplasia, pregnancy, etc)
What is the pathophysiologic of hypertrophic osteopathy
1) Irritation of afferent nerves by primary mass
2) Neurally (vagus) mediated reflex
3) Increase peripheral blood flow
4) Connective tissue/periosteum congestion
5) New periosteal bone deposition
How do you treat hypertrophic osteopathy
1) Remove/treat primary lesion - bone lesions regress within weeks as periosteal new bone remodels
pain resolves within weeks
What is the prognosis of hypertrophic osteopathy?
depends on the primary lesion
recurrence of tumor or metastatic disease
What is the difference between congenital and developmental diseases
Congenital= born with (birth defects) that can be inherited or caused by chemicals or injury during pregnancy
Developmental:
caused by disturbances in the development and maturation of the musculoskeletal system, in particular the articular and metaphyseal cartilage
caused by disturbances in the development and maturation of the musculoskeletal system, in particular the articular and metaphyseal cartilage
developmental disorder
born with (birth defects) that can be inherited or caused by chemicals or injury during pregnancy
congenital defects
disruption of endochondral ossification due to rapid growth
can be osteochondral (with subchondral bone) or cartilaginous flap (without bone)
causes pain, effusion, lameness and osteoarthritis long term
osteochondrosis dissecans
What happens when osteochondrosis dissecans fragment is removed
fibrocartilage fills the gap,
In dogs, what 4 joints does OCD occur in *
1) Shoulder
2) Elbow
3) Tarsus
4) Stifle
In dogs, what joints does OCD not occur in *
1) Hip
2) Carpus
How do you diagnose shoulder OCD in dogs
rads are frequently sufficient
In dogs, OCD in the ________ joint has the best prognosis
shoulder, especially for caudal lesions
the elbow/tarsus/stifle have questionable benefit of surgery/fair-poor
How do you need to diagnose elbow, tarsus, and stifle OCD?
often times CT is frequently needed
What does OCD in the shoulder of dogs look like radiographically
flattenining of the caudal humeral head
CT is generally not required if rads are obvious
How do you treat OCD in dogs
-Flap removal: simple + cheap, fibrocartilage fills in
-Focal procedure: OATS, synthetic OATS
-Regenerative Medicine: Stem cells, PRP
What is another name for hypertrophic osteodystrophy
Metaphyseal osteopathy
disruption of the metaphyseal trabeculae in long bones of young, rapidly growing dogs
hypertrophic osteodystrophy
What kind of dogs does hypertrophic osteodystrophy typically occur in?
young, rapidly growing dogs
3-6 months (early as 2 mo)
males are more common than females
may involve several or all littermates
Are male of female puppies more likely to get hypertrophic osteodystrophy
males, esp giant/large breed dogs 3-6 months
What are the clinical signs of hypertrophic osteodystrophy
-slight limp to non-weight bearing to recumbent
-swollen, hot, painful, Metaphysis, (usually bilateral)
-Episodic signs
-Sick systemic signs: fever, depression, anorexia, diarrhea, weight loss
In hypertrophic osteodystrophy, puppies will be swollen, hot, and painful at the
metaphysis (usually bilateral)
What do you see on clin path in a dog with hypertrophic osteodystrophy
usually normal
-leukocytosis
-mild anemia
-bacteremia (rare)
What do you see radiographically in dogs with hypertrophic osteodystrophy
1) *a double physeal line
2) Endosteal density with layers of lucency
3) Irregular periosteal proliferations at the metaphyseal level
Later stages:
1) Retained cartilage cores
2) Premature physeal closures
3) Diaphyseal lesions
You see a 4month old puppy that presented with bilateral swelling, upon radiographic signs you see a double physeal line and endosteal denstiy with layers of lucency
and irregular periosteal proliferations at the metaphyseal level.
What is the diagnosis
hypertrophic osteodystrophy
What radiographic changes do you in late hypertrophic osteodystrophy
1) retained cartilage cores
2) premature physeal closures (leading to ALD)
3) diaphyseal lesions
hard to differentiate from HOA- specifically fungal lesion in the chest
What radiogrpahic changes do you see in early hypertrophic osteodystrophy
1) *a double physeal line
2) Endosteal density with layers of lucency
3) Irregular periosteal proliferations at the metaphyseal level
What causes hypertrophic osteodystrophy
unknown etiology
-canine distemper virus
-Previous vaccination
-Hereditary causes
-Auto-immune disorder
What are common differentials when considering hypertrophic osteodystrophy
septic arthritis
Panosteitis
What are common locations for hypertrophic osteodystrophy
radius, ulna, and tibia
(also mandible)
What is the pathogenesis of hypertrophic osteodystrophy
1) Disturbance in metaphyseal blood supply
2) Delay/failure in ossification of the physeal hypertrophic zone (delayed endochondral ossification)
3) Retained cartilage, extends into the metaphyseal trabeculae
4) Trabeculae fractures, leading to hemorrhage and inflammation
5) Trabecular fractures causes lifting of the periosteum and new bone production (Codmans triangle)
How do you treat mild cases of hypertrophic osteodystrophy
Supportive care: analgesia with NSAIDs, GI protectants, and rest
prognosis: good to excellent, relapses may occur
NEED regular rechecks as angular limb deformities are possible
Why do you need to recheck hypertrophic osteodystrophy mild cases frequently
can lead to angular limb deformities
How do you treat severe cases of hypertrophic osteodystrophy
more advanced supportive care: enteral nutrition, antibiotics
prognosis: guarded to poor, long-term support needed, angular limb deformities are common
What is the typical signalment of panosteitis
7-16 months (teenagers)
reported to occur up to several years of age
-rapidly growing larger and giant breeds (german shepherds)
80% males
Panosteitis typically occurs in males or females
Males 80%
Panosteitis typically occurs in what kind of dogs?
rapidly growing larger and giant breed dogs
German shephards
What causes panosteitis
1) Idiopathic
2) Osseous compartment syndrome due to protein rich diet
-Genetic
-Autoimmune reaction
-Viral osteomyelitis (CDV) or vaccine response
-Bacterial osteomyelitis
What kind of lameness is seen with panosteitis
acute shifting limb lameness
pain wuth direct pressure over the affected diaphyseal region
Dogs with panosteitis have pain with direct pressure over the
affected diaphyseal region
Where in the bone does panosteitis typically occur
diaphysis
frequently forelimb (radius/ulna) first then humerus, femur, tibia
What are the clinical signs of dogs with panosteitis
-Acute shifting limb lameness
-Pain with direct pressure over affected diaphyseal region
-Intermittent mild fever, lethargy, anorexia
Bloodwork WNL
How do you diagnose panosteitis
Radiographs, nuclear scintigraphy, CT
Radiographs:
-Increased radiolucency at the nutrient foramen
-Unifocal increased intramedullary density
-Multiple, coalescing foci of increased radiolucencies
-Indistinct endosteal surfaces
-Mild periosteal reaction
radiograph findings lag at leasy 7 days behind clinical symptoms
What are the radiographic findings of panosteitis
1) Increased radiolucency at the nutrient foramen
2) Unifocal increased intramedullary density
3) Multiple, coalescing foci of increased radiolucencies
4) Indistinct endosteal surfaces
5) Mild periosteal reaction
At what age do dogs typically get panosteitis
7-16 months old (can occur up to several years of age)
How do you treat dogs with panosteitis
-Typically self limiting
-Check diet
-NSAIDs/pain meds
prognosis: excellent but multiple bouts happen frequently
best prognosis amongst juvenille diseases
a rare congenital bone abnormality that affects the soft tissue and bones of a dog’s thoracic limbs. It’s also known as split-hand deformity
ectrodactyly
Very young animals
can be very sick
double physis
supportive care
prognosis depends on severity of case
hypertrophic osteodystrophy
teenager to adult dogs
shifting lameness with no systemic signs
Increased opacities
Pain meds and rest
excellent prognosis
Panosteitis
older animals
swollen limbs, ADR
pallisading lesions
remove mass
prognosis depends on underlying disease
hypertrophic osteopathy
What is the highmovement joint of the dog tarsus
Tarsocrural
T/F: Tarsal OCD is rare
True
Varus/Valgus can place stress on the _____ of the carpus
collateral ligaments
How do you test the collateral ligaments of the carpus
varus/valgus stress
-short branch: flexed
If you take a DMPLO of the dogs tarsus, what is it highlighting
Dorsolateral and medial palmar
What are the 4 standard radiographic views you take of the hock/tarsus
1) Lateral
2) DP
3) DMPLO
4) DLPMO
if collateral rupture: stress views
Tarsal OCD affects the
talus (often bilateral)
medial ridge (60-80%) > lateral risge > both ridges
What site of the dog’s tarsus is the most common site of OCD
medial ridge of the talus
What is the signalment of dogs with tarsal OCD
developmental = young, large breed dogs Male > female
adult dogs with arthritis (secondary changes)
What are the radiographic findings of tarsal OCD
1) Frequently have tarsal hyperextension
2) + Sit test (DD: CCLD)
3) Joint effusion * (severe) /periarticular swelling
4) Painful ROM (especially flexion)
5) Rear limb lameness (unilateral or bilateral)
6) Acute onset or slow insidious, chronci progressive
7) Stiff, slow lame after cool down
Dogs with tarsal OCD are painful when the tarsus is
flexed - dogs with tarsal OCD typically have tarsal hyperextension
What are the radiographic findings of dogs with Tarsal OCD
Medial and lateral ridges of talus
if lesion is not detected, does not rule out OCD
DP skyline is useful
CT allows accurate localization required for surgery
How do you treat OCD of the tarsus surgically
1) Removal and debridement of fragment
2) unloading osteotomy: that moves load onto the lateral compartment
arthrodesis (end-stage)
Total ankle replacement
What causes carpal hyperextension
traumatic disruption of palmar fibrocartilage
When taking goniometry measurements, always measure on the
flexion surface
carpal hyperextension can occur due to carpal injury at what levels
1) Antebrachiocarpal
2) Middle carpal
3) Carpometacarpal
Is splinting more likely to be successful for antebrachiocarpal or carpometacarpal hyperextension injuries
Antebrachiocarpal
traumatic disruption of palmar fibrocartilage of the carpus
most common injury of the carpus
fibrocartilage does not heal
carpal hyperextension
The treatment of carpal hyperextension depends on
Severity
Mild cases (not dropped) are amenable to coaptation
Severe cases (palmigrade): require arthodesis
How do you treat mild cases of carpal hyperextension (not dropped)
amendable to coaptation
How do you treat severe cases of carpal hyperextension (palmigrade)
Arthrodesis is requires
Pancarpal= all carpal joints
Partial= distal carpal joints (all except antebrachial-carpal joint)
How do you diagnose collateral ligament injury
visual instability/ abnormal stance
palpable instability
How do you treat first degree (stretch) / mild tarsal ligament injuries
Rest, ice, compression, elevation
NSAIDs
+/- soft padded bandage
How do you treat second degree (partial) / moderate tarsal ligament injuries
external coaptation
How do you treat third degree (complete)/ severe tarsal ligament injuries
Surgery vs support
Ligament repair / augmentation
-Anchors
-Bone tunnels
via locking loop
Support: Splint vs hinged orthotic or trans-articular fixator (lots of fibrosis and less ROM)
What suture pattern is best for collateral ligament repair
locking loop
Which locations are feasible for primary (suture) repair?
A) Carpal hyperextension (inter carpal ligaments
B) Achilles mechanism (common calcanean tendon, gastrocnemius, SDF)
C) Cranial cruciate ligament
D) Tarsal medial collateral ligament
B) Achilles mechanism (common calcanean tendon, gastrocnemius, SDF)
D) Tarsal medial collateral ligament
carpal has too many
CCL will fail
surgical procedure to fuse a joint
arthrodesis
you can do partial arthrodesis on what carpal and tarsal joints
any of the distal low motion joints
-less morbidity / complications
-ensure high motion joint is not involved
-some partial carpal may breakdown -> PanCA
Pan-Arthrodesis
full fusion of all joints
-injuries that involve high motion joint
-last resort (salvage)
T/F: you can reverse arthrodesis
False
What are the principles of arthrodesis
1) Remove all cartilage, forage bone
2) Use bone graft (from proximal tibia, ilium, humerus) to encourage fusion of the bone
3) Fix at a standing angle
4) Provide stable fixation (bone plates) +/- splint
high rate of complications
Where should you get bone graft from
proximal tibia
proximal humerus
ilium
What are the high motion joints of the carpus and tarsus
Antebrachiocarpal
Tarsocrural joint
(90% of joint motion)
What are complications of arthrodesis
highly technical sx
-plate fixation in most cases
ESF if infection/wounds
monitor for complications (10%)
-implant failure / delayed union
-wounds
How should you manage dogs after arthrodesis
1) splint/cast bandage care
2) monitor for complications (10%)
-implant failure/delayed union
-wounds
3) Encourage controlled weight bearing
4) Slow bone healing (radiographs at 6 + 12 weeks)
5) Good function with extremity joints once healed
T/F: tarsal OCD in dogs has a good prognosis *
False - therefore aggressive/novel intervention is needed
What is the common signalment and history of dogs with Cranial Cruciate ligament tear
middle aged
medium to large breed
normal activity “weekend warrior”
How does CCL tear differ from in dogs from humans
dogs have a higher tibial plateau angle (TPA): 25-30 degrees
ligament degeneration vs acute injury
What is the normal tibial plateau angle of dogs?
25-30 degrees
What is the typical signalment for dogs w CrCL acute avulsion injury
young (skeletally immature) athletic dogs
subchondral bone is weaker
What is a risk factor for early CrCL ligament rupture in dogs
1) Early neutered (growth plates stay open longer)
2) Straight legged conformation
leads to higher TAP and risk factor for early rupture
early neutering leads to
growth plates staying open longer and orthopedic diseases
How do small dog breeds present with Cranial Cruciate ligament disease
Older, overweight
acute complete rupture
may be secondary to MPL (due to internal stifle rotation)
Small dog breeds might have acute complete CrCL rupture due to
1) may be secondary to MPL- internal stifle rotation and increased mechanical stress
2) Older, overweight
How would CrCL partial tear present
lameness may be prolonged, intermittent and mild
How would CrCL complete tear present
acute and severe
How would a secondary meniscal injury present
lameness may partually improve then becomes and stays severe
CrCL tear is worse _________ and improves with
after strenuous exercise
after prolonged rest
improves with rest/ activity exercise restriction
improves with NSAIDs
How will a dog move with CrCL disease
significant lameness in the hindlimb
-shifting weight away from the leg
-hip moves up
-may plant good leg closer to midline forcefully
What are the two diseases that would lead to a positive sit test
1) Cruciate disease
2) Tarsal OCD
What muscle becomes atrophied with CrCL disease
quadriceps muscles
What are signs of CrCL disease on stifle manipulation
Pain on ROM
Cepitus/clicks
instability
With a sit test, how do you lateralize a lesion
shifts weight away from the lame leg
How do dogs with bilateral CrCL disease move
lower head movement
weight shifting forward or doesnt want to sit when sitting
______% of dogs that present for unilateral CCLD, present with lameness on the contralateral limb within 2 years
50%
Dogs with CrCL disease have pain on
full flexion and extension
Where do you assess for stifle effusion in a dog
on either side of the patellar tendon
if chronic: periarticular tendon
effusion makes patellar tendon less distinct
For cranial drawer motion, how do you position your proximal hand
thumb: lateral fabella
index: patella
shift the distal side while stabilizing the proximal side
thickening of fibrous tissue along the medial aspect of the stifle joint
medial buttress
seen with chronicity of cruciate disease
When is medial buttress felt
seen with chronicity of cruciate disease
For cranial drawer motion, how do you position your distal hand
thumb: fibula head
index: tibial tuberosity
shift the distal side while stabilizing the proximal side
With caudal cruciate ligament tear, how does the drawer motion feel
caudal cruciate drawer motion, stifle doesnt stop when moved caudally
In tibial compression test, what prevents the tibia from moving forward
intact cranial cruciate ligament
Why is tibial compression test more valuable than cranial drawer test
1) More tolerable by the patient, instability can be determined
2) Can be done in standing exam
3) Caudal CL tears do not have cranial tibial crust
T/F: many dogs with significant CrCL disease will not have much instability to cranial drawer or tibial thrust
True- look for other signs
What radiographic view is best for CCLD diagnostics
lateral projection is most useful
assess
1) effusion
2) osteoarthritis (OA)
What are the radiographic findings of dogs with a partial CCL tear
1) fluid/soft tissue density displacing the fat pad
2) stifle is outpouched by effusion
3) ostephytes can form (trochlear ridge, distal patella, around fabella, tibial plateau)
In dogs with CCL tear, where are common sites to see osteophytes
1) trochlear ridge
2) Distal patella
3) Fabella
4) Tibial plateau
When taking a stifle radiograph for CCLD, what do you do if the patient is too big to focus on both the stifle and tibia
take two radiographs and superimpose them onto each other
How do you measure tibial plateau angle
Functional axis: intercondylar eminence to middle of weight bearing surface
measure line across the tibial line
angle between the perpendicular to the functional axis and the tibial slope
tibial plataeu angle
angle between the perpendicular to the functional axis and the tibial slope
What is an excessive TPA
> 35 degrees
Patients that have a higher TPA (>30) are poor candidates for
Poor candidates for
1) Conservative management
2) ExCap- suture under stress
3) TTA- further you have to advance tuberosity
Best treated with TPLO
Patients with a TPA >30 are best treated with
TPLO
Dogs with caudal CL tear do not have
tibial thrust
What are the radiographic findings of a dog with a complete cranial cruciate ligament tear
1) Cranial tibial subluxation
Nx: Eminence should sit under the ball of the femoral condyle
Complete tear: you see the eminence be more cranial to the femoral condyle
crescent and wedge shaped fibrocartilages important in load bearing and load distribution of the stifle
Meniscus
What meniscus is most prone to injury after CrCLD
caudal pole of the medial meniscus
-femoral condyle roles onto it
Why is the caudal pole of the medial meniscus most prone to injury after CrCLD
tagged down to tibia via ligament while the lateral meniscus is tapped down to femur
the repetitive caudal pole ramming damages the caudal pole of the medial meniscus
With CrCL injury how often does meniscal injury occur
50-90% of the time
T/F: isolated meniscal tear to lateral meniscus is common
false
caudal pole of the medial meniscus
commonly tears after CrCl tear
what are the different types of meniscal tears
Radial: 2mm tear
Complex: multidirectional tears and crushing of tissues
Vertical Longitudinal: non displaced, involving the whole caudal pole
Displaced Vertical Longitudinal (non-reducible bucket handle)- crushed
Flap: transected bucket handle
How do you treat radial meniscal tears
no treatment
How do you treat complex meniscal tears (multidirectional tears and crushing of tissues)
all of the caudal pole (hemi-meniscectomy)
How do you treat longitudinal meniscal tears?
partial meniscectomy
How do you assess for meniscal injury with CrCL disease
must insepct via arthrotomy or arthroscopy
probing increases diagnostic accuracy by 8 times
When is conservative management for CrCL disease indicated
dogs <15kgs with acceptable limb function
smaller and less athletic dogs
reported success rates of 84-90%
For CrCL disease, what are the goals with surgery management
1) Address an concurrent meniscal injury
2) Reestablish joint stability
3) Mitigate secondary osteoarthritis
At what weight is CrCL conservative management considered acceptable recovery
80% reach acceptable recovery if <15kg
What improves the results of CrCL conservative management in small dogs
weight loss
What are the cons of CrCL Extraarticular Stabilization (ExCAP)
1) Fails to maintain stability
2) Progressive OA
3) Does not prevent late meniscal damage
4) No perfectly isometric suture (hard to anchor and doesnt last long)
5) Not good for high performance
a procedure where suture of nylon leater line is used to anchor the cranial tibia to the caudal femur in CrCL
CrCL Extraarticular Stabilization (ExCAP)
What are procedures that function to decrease the tibial plateau angle
1) Cranial tibial closing wedge osteotomy (CTWO)
2) Tibial Plateau Leveling Osteotomy (TPLO)
3) Combined CTWO and TPLO
4) Proximal intraarticular osteotomy
5) Chevron Wedge Osteomy
What procedure functions to alter the alignment of the patella tendon for CrCL tears
Tibial Tuberosity Advancement (TTA)
What procedure functions to both decrease the tibial plateau angle and alter the alignment of the patella tendon
Triple Tibial Osteomy (TTO)
What TPA is the goal of TPLO
6 degrees
A procedure used for a CrCL deficient stifle where the joint reaction force is parallel to longitudinal axis of tibia and tibial plateu
thrust elmininated
used to change the angle via semicircle cut and rotation of the caudal proximal tibial bone
TPLO
a procedure to CrCLD where a cut in the tibia is made to make a 90 degree between tibial plateu and patellar tendon
Tibial Tuberosity Advancement (TTA)
Why is the Tibial Tuberosity Advancement (TTA) a lot less reliable
relationshop of tibial plateu and patellar tendon being 90 degrees is changed due to positioning of the stifle and quadriceps/hamstrings balance
doesnt always provide good stabilization
With a Tibial Tuberosity Advancement (TTA), what should be perpendicular to each other
patellar tendon and tibial plateau
What are considerations when deciding to do ExCap vs TPLO vs TTA
-Owners goals, financial constraints
-Patient signalment, activity
-Degree of instability
-Tibial plateau angle and conformation
-Concurrent patella luxation
What CrCL treatment has the fastest return to comfortable function
TTA
TTA > TPLO > ExCap > Conservative
What procedure should you do if a patient has an excessive TTA (ex 60 degrees), where in TPLO you cant rotate the tibia that much
Modified cranial closing wedge osteotomy
What is the CrCL prognosis after surgical intervention
all surgical techniques quote 80-90% return to normal function
With CrCL disease, you often see _____ contralateral CrCL rupture within ________
50% contralateral CrCL rupture within 12-18 months
What is the pathogenesis of patella luxation *
Primary malalignment of extensor mechanism
1) Shallow trochlear groove (never forms)
2) Malpositioning of tibial tuberosity
3) Distal femoral varus
4) Excessive laxity and fibrosis of soft tissues
what patella luxation is most common
Medial patella luxation is most common in all breeds, especially small breeds
What is the most common patella luxation in small breeds
Medial patella luxation
What is the most common patella luxation in large dogs
medial patella luxation
Lateral patella luxation is usually in
larger breed dogs, but it is still more common for large dogs to get medial
a patella that subluxates with digital pressure but spontaneously reduces
rare spontaneous luxation and lameness
Grade I Patella Luxation
What causes patella luxation
Primary malalignment of extensor mechanism
1) Shallow trochlear groove (never forms)
2) Malpositioning of tibial tuberosity
3) Distal femoral varus
4) Excessive laxity and fibrosis of soft tissues
What are the 4 primary ways a dog might get patella luxation
1) Shallow trochlear groove (never forms)
2) Malpositioning of tibial tuberosity
3) Distal femoral varus
4) Excessive laxity and fibrosis of soft tissues
T/F: grade 1 patella luxation is normal in cats
true- possible. cats have a very mobile patella
a patella that luxates manually and spontaneously
can be manually reduced or spontaneously reduces but spends most of its time in the groove
may have intermittent lameness of skipping lamness
Grade II Patella Luxation
What lameness is seen with Grade II Patella luxation
may have intermittent lameness of skipping lameness
What lameness is seen with Grade I Patella luxation
rare spontaneous luxation and lameness
patella is luxated, but can be manually reduced
may walk crouched with stifle semi-flexed
patella spends more time out than in
constant lameness out and internally rotated stifle
Grade III Patella luxation
patella is permanently luxation and cannot be reduced
may carry limb or walk crouched
severe gait changes (hand-stands)
Grade IV Patella Luxation
What are the different grades of patella luxated
1) Subluxated with digital pressure but spontaneously reduces, rare spontaneous luxation and lameness, normal in cats
2) Luxates manually and spontaneously, can be manually reduced or spontaneously reduces, spends most of its time in the groove, intermittent lameness or skipping lameness
3) Patella is luxated but can be manually reduced, may walk crouched with stifle semi-flexed, patella spends more time out than in
4) Permanently luxated and cannot be reduced, may carry limb or walk crouched, severe gait changes (hand-stands)
How do you assess for patella luxation in a dog
lameness varies with grade
-standing exam most useful
-slighting extend and internally rotate the stifle
What are MPL surgical considerations
-How clinically affected is the patient
-Frequency and severity of lameness
-Performance goals
-Grade of MPL
Do you recommend sx for grade I and II patella luxations
only indicated if clinically significant
When is sx for MPL indicated
Grade 1-2 (if clinically significant)
Grade 2-3: recommended to minimize arthritis and may avoid cranial cruciate disease
Grade 4: severe bony and ligamentous deformities may not be repairable if not corrected early
Why is surgery of grade II to III MPL indicated
recommended to minimize arthritis and may avoid cranial cruciate disease
Grade 4 MPL surgery
severe bony and ligamentous deformities may not be repairable if not corrected early
how do you fix the primary malalignment of extensor mechanism caused by a shallow trochlear groove
Trochleopasty
How do you fix the primary malalignment of extensor mechanism caused by malpositioning of tibial tuberosity
Tibial Tuberosity Transposition (TTT)
How do you fix the primary malalignment of extensor mechanism caused by distal femoral varus
Distal femoral osteotomy (DFO)
How do you fix the primary malalignment of extensor mechanism caused by excessive laxity and fibrosis of soft tissues
-Fascia imbrication and/or release
-Anti-rotation suture (ex: ExCap)
What are the complications of MPL sx
-reluxation or overcorrection (MPL -> LPL)
-owners should be forewarned of potential for second surgery
guarded prognosis for grade IV
How do you tell good positioning of a stifle radiograph
you want superimposition of the femoral condyles
A dog presents to you for suspected medial patella luxation. The owner reports seeing an intermittent “skipping” right hind limb lameness around 2-3 times a week that lasts for only 5 to 10 mins. When you palpate the dog’s right stifle the patella luxates medially with gentle medial pressure and internal rotation of the stifle, but was in the correct position to begin and returns to a normal position after you release pressure on the stifle. What grade of MPL is this most consistent with?
Grade 2/4 MPLs are in the normal position the majority of the time, but can spontaneously luxate.
What 3 joints make up the canine elbow
1) Humeroradial - weight bearing function
2) Hueroulnar - restruicts motion to sagittal plane
3) Proximal radioulnar - transverse plane pronation/rotation
what joint of the elbow is important for weight bearing function
humeroradial
what joint of the elbow is important for transverse plane pronation/rotation
proximal radioulnar
what joint of the elbow is important for restricting motion to the sagittal plane
humeroulnar
what is the lateral componet of the humerus that articulates with the radial head
capitulum
what is the medial component of the humerus that articulates with the medial portion of the ulnar coronoid process
trochlea
How do you diagnose coronoid disease (MCD)
1) CT
2) Scope
Rads can give supportive information but never a definitive dx
How do you diagnose ununited anconeal process
flexed lateral radiograph
How do you rule out elbow incongruity
1) CT
2) Scope
Rads are only to rule out large incongruity
How do you diagnose OCD of the canine elbow
CT
Rads will not pick up much
What plays an important role in MCD and UAP
elbow incongruity
if there is humeral-radial incongruity there will be more load on the coronoid
where the elbow joint surfaces dont match. can occur in 3 joints
-humeroulnar
-proximal radioulnar
-humeroradial
incongruity
What is humeroulnar incongruity called
notch incongruity “C shape”
What occurs when the radius is too short
1) pressure on coronoid process
2) medial coronoid disease
3) Radioulnar incongruency
What occurs when the ulna is too short
1) Pressure on anconeal process
2) UAP
3) Radioulnar incongruency
Short ulna leads to
UAP
Short radius leads to
MCD
What procedure is done for a long ulna (short radius) = MCD
Ulna ostectomy- allows shortening of ulna
What procedure us done for a short ulna = UAP
Ulna osteotomy- triceps pull restores elbow congruity by pulling ulna proximally dynammically
proximal- above interosseus ligament (adult)
distal- below interosseous ligament (growing)
Ulna osteotomy is for ________
Ulna ostectomy is for ________
osteotomy for short ulna (UAP)
ostectomy is for short radius (MCD)
pathology of the medial aspect of coronoid process (ulna)
Fragmented coronoid process (FCP) / Coronoid or medial compartment disease
What causes coronoid disease
unknown pathogenesis
-genetic component proven
-incongruity (static or dynamic or temporary)
-not limited to fragment itself
-very diverse disease
How do you diagnose coronoid disease
1) PE
2) Rads (50-70% accurate)
3) CT- good for osseous evaluation and incongruity
4) Arthroscopy- good for cartilage evaluation and incongruity
What is the typical signalment of dogs with coronoid disease
large breed dogs (Labs, GSD, rotties, goldens, etc)
usually 6-18 months
history:
variable lameness, worse after exercise
stiff gait after rising
lazy but will still play
often bilateral so difficult to notice
How old are dogs with coronoid disease typically
6-18 months
Is cornoid typically bilateral or unilateral
bilateral
What do you notice on your physical exam in dogs with coronoid disease
-abnormal stance
-pain on palpation (hyperflexion, extension, and medial compartment pressure/palpation
-crepitus, reduced ROM, and swelling in older arthritic patient
-Campbells test
Test for dogs that assesses the collateral ligaments in the dog’s elbow. To perform the test, the dog’s elbow and carpus are positioned at 90° flexion, and the dog’s paw is then externally rotated. The amount of external rotation the dog’s paw can achieve indicates the condition of the collateral ligaments. The average amount of pronation for a dog’s elbow is 30°, and the average amount of supination is 50°.
campbells test
What do we look for on radiographs in dogs with coronoid disease
1) Discontinuity of coronoid process
2) Osteophytes on anceoneal process and cranial aspect of the proximal portion of the radial head
3) ulnar sclerosis
4) fragment occasionally on A/P view
In coronoid disease, fragments are best seen on the
A/P view
What CT view is used to assess elbow incongruity
sagittal
What CT view is used to assess cornoid fragments
transverse
How do you treat coronoid disease?
-Arthroscopic debridement? - remove
-Subtotal coronoidectomy- removing base of coronoid to prevent future fragments from breaking off
-Ulnar ostectomy for incongruity (ie long ulna/short radius)
-Arthritis management
removing base of coronoid to prevent future fragments from breaking off
Subtotal coronoidectomy
What is the prognosis of dogs with developmental MCD
depends on the severity of DJD
surgery recommended to slow down arthritis progression and decrease lameness
not a cure
everything should be done to preserve a joint because otherwise it will not look good
In developmental coronoid disease how does the diagnosis differ between puppies and adult dogs
Puppies: severe ED but little DJD- may need CT for diagnosis
Adult dog with moderate ED but severe DJD- rads are adequate for diagnosis
Adult onset form of coronoid disease
rare but any mid-older aged dog with minimal radiographic changes
traumatic in origin
developmental but not clinically
-need CT or arthroscopy for diagnosis
In the dog, where do they get OCD in their elbow joint
Medial humeral condyle
How do you diagnose humeral OCD?
CT/arthroscopy
How do your treat elbow OCD in dogs
-excision of cartilage flap
-curettage and microfracture/picking of the subchondral bone
-OATS
What is the prognosis of humeral OCD in the dog
DJD inevitable
medical OA
Humeral OCD is often accompanied by
coronoid fragment on ulna
UAP is an anconeal process that doesnt unite by
week 20
Anconeal process that doesnt united by week 20
ununited anconeal process
What is the typical signalment of UAP
young, large/giant breed dogs (GSD, Berner)
Male:female = 2:1
T/F: UAP is bilateral disease
about 20-35% of the time
What is the pathogenesis of UAP
1) Nutrition, genetic, trauma, OCD
2) Incongruity (elbow dysplasia) - short ulna
3) Incongruity (traumatic)- premature closure of distal ulnar physis
4) Concomitant disease: MCD ~15%
What are the exam findings of UAP
-Mild to moderation lameness
-Pain on hyperextension
-joint effusion *
Dogs with UAP will have pain on elbow
hyperextension
What radiograph view is best to diagnose UAP
flexed view- to eliminate superimposition of humerus
How do you diagnose UAP
1) flexed view radiograph- to eliminate superimposition of humerus
2) CT/ arthroscopy to evaluate MCD and incongruity
How do you treat UAP
1) Removal of UAP- leads to elbow instability or DJD
2) Ulna osteotomy: morbidity associated with osteotomy or failure of fusion/DJD
3) Lag-screw fixation (with or without osteotomy)- implant associated morbidity or failure of fusion/DJD/ additional surgeries
What are possible negative outcomes of removal of UAP
1) Elbow instability
2) DJD
What are possible negative outcomes of ulna osteotomy for UAP
morbidity associated with osteotomy or failure of fusion/DJD
What are possible negative outcomes of lag-screw fixation (with or without osteotomy)
implant associated morbidity or failure of fusion/DJD/ additional surgeries
How common is OA in small animals
Really common
20% of dogs over 1 year
35% of all dogs clinically affected by OA
>60% of adult cats diagnosed
T/F: OA is curable
False- incurable
cushioning support that allows support of the joint and doesnt have a direct blood supply and relies on diffusion for nutritional support
Articular cartilage
produces and filters synovial fluid
joint capsule
what are the two layers of the joint capsule
Stratum fibrosum
Stratum synovium
produced by joint capsule and bathes articular cartilage
synovial fluid
What are the components of articular (hyaline) cartilage
Cellular component: chondrocytes and chondroblasts
Extracellular matrix:
collagen (mostly type II)
proteogylcans (mostly aggrecan which contains negatively charged GAGs chondroitin and keratin sulfate)
Water
What gives cartilage the ability to resist compressive forces and support the cells
osmotic swelling pressure
What pumps waste and nutrients in and out of the cartilage
compressive forces
What causes osteoarthritis in small animals
1) Idiopathic (primary)
2) Secondary: to dysplasia- extracellular matrix is destroyed
What factors predispose dogs to osteoarthritis
1) Genetics
2) Age
3) Systemic factors (ie obesity)
in OA, what breaks down components of the ECM
enzymes (MMPs, aggrecanases, collagenases)
pathogenesis of OA in dogs
1) enzymes (MMPs, aggrecanases, collagenases) breakdown components of ECM
2) Pro-inflammatory mediators (ie IL-1b, TNFa) - increased vascular permeability, increased white blood cells and proteins in synovial fluid
3) Pain signaling proteins (NGF)- decrease pain threshold, central sensation
In OA, what do pro-inflammatory mediators (ie IL-1b, TNFa) do
increased vascular permeability, increased white blood cells and proteins in synovial fluid
In OA, what do Pain signaling proteins (NGF) do?
decrease pain threshold, central sensation
What are the clinical findings of dogs with OA
Crepitus: osteophytes and subchondral bone sclerosis
Range of Motion: synovitis and capsular fibrosis, pain, and stiffness
Effusion: Increased vascular permeability, infiltration of inflammatory mediators, ECM degration
Pain: central nervous system changes (pain sensitization), inflammation
Instability: frequently inciting cause
With bilateral hindlimb lameness, what should you include on your neuro examination
Withdrawal reflex
Patellar reflex
Placing Responses
What is multimodal OA approach in dogs
1) Prevention
2) Client education
3) Surgery
4) Weight
5) Pharmacologics
6) Nutraceuticals/disease modifying agents
7) Physical rehabilitation
8) Joint injections
How do you prevent OA in dogs
1) Breeding: heritability of pre-disposing conditions (elbow and hip dysplasia)
2) Nutrition: calcium (puppy food) and calories (too many calories, will grow too fast)
3) Spay/neuter: castration correlated with increased risk of orthopedic disease (hip dysplasia, CCLD)
Surgery for OA management in dogs
1) treat underlying disease (ie arthroscopy for shoulder OCD)
2) treat instability (ie TPLO)
3)treat clinical signs (ie arthrodesis, joint replacement)
in treating canine OA, what lifestyle adjustments need to be made
-moderated activity
-daily routine and environment
-consider: harness, booties, slings, rugs/yoga mats, elevated food bowls, ramps/stairs
What BCS should be maintained to prevent OA
Ideal (4-5)
increase in median lifespan by almost 2 years
What are the benefits of limited food consumption in dogs with OA
-Delayed onset of OA and other degenerative diseases
-Decreased incidence of multi-joint OA at 8 years
-Substantially increased lifespan
Each point over 5 means the dog is ________ overweight
10-15% overweight
How do you calculate ideal BW
current body weight / 100% + %overweight
(%overweight = 10-15% for every point over 5)
calculate RER based on IBW
kcal/day = 70 x IBW ^0.75
What are important dietary considerations
1) <10% of total caloric intake dedicated to treats
2) Consider prescription weight loss diet
3) Reducing calorie consumption more important than exercise
4) Aim for 1-2% weight loss per weight
Is reducing calorie consumption or exercise more important in managing OA
reducing calorie consumption
an anti-inflammatory that is a prostaglandin receptor antagonist
Galliprant
an adjunctive agent for chronic and neuropathic pain
gabapentin
an opioid receptor agonist that doesnt do anything for OA
tramadol
an NMDA receptor antagonist for chronic pain
Amantadine
a tricyclic antidepressant for chronic pain
Amitriptyline
What NSAID is safe for cats with stable CKD
low dose meloxicam (0.02mg/kg/d)
Different phamacologics for OA in dogs
NSAIDS
Galliprant
Gabapentin
Tramadol (not good)
Amantadine
Amitriptyline
Acetominophin +/- codeine (not for cats)
dietary supplement intended to provide health benefits beyond prevention of deficiencies in essential nutrients
Nutraceuticals
T/F: FDA functions to regulate nutraceuticals
False- there is no regulatory body for animal supplements
it arbitrarily falls under FDA-CVM
What are three nutraceuticals with good efficacy
1) Omega 3 fatty acids
2) Undenatured collagen type II
3) PSGAGs
make sure they have NSAC approval
What is the mechanism of omega-3 fatty acids in OA
anti-inflammatory
-competes with arachidonic acid as substrates for COX and LOX enzymes
-may also reduce MMP
What is the nutraceutical with the most evidence for OA management
omega-3 fatty acids
What is the recommeneded does of EPA +DHA for canine osteoarthritis
310 x IBW (kg) ^0.75
What are the dose dependent adverse outcomes of omega-3 fatty acids in dogs
diarrhea and adverse effects on platelet function
What should you consider when supplementing a dog with omega-3 fatty acids
the calories
120kcal/tbsp
What is the mechanism of action of undenatured collagen type II
induction of oral tolerance
Treg cells target type II collagen to release of anti-inflammatory mediators in joint cartilage (TGFb, IL-4, IL-10)
What nutraceutical is not bioavailable when taken orally
glucosamine/chondroitin
What is mechanism of action of PSGAGs
catabolic enzyme inhibitor (MMPs)
enhances anabolic activity of chondrocytes and synoviocytes
-HA
-Collagen
-PGs
binds to cartilage to prevent further degradation
labeled IM but can be administered SQ
catabolic enzyme inhibitor (MMPs)
enhances anabolic activity of chondrocytes and synoviocytes
-HA
-Collagen
-PGs
binds to cartilage to prevent further degradation
labeled IM but can be administered SQ
PSGAGs (adequan)
What is the tradename of PSGAGs
Adequan
What are goals of physical rehabilitation
strengthen periarticular core and postural muscles
maintain soft tissue flexibility and joint ROM
alleviate compensatory muscle tension and pain
improve balance and proprioception
What exericse is important for OA
regular, low impact exericse
-leash walks (grass >pavement)
-hydrotherapy
advanced rehabilitation
target affected joints/muscles
strengthen periarticular muscles
-improve muscular shock absorption
-minimize fatigue related injury
alleviate compensatory muscle tension, pain, and myofacial trigger points
-improve comfort
-improve joint ROM
What steroid is typically used in dogs for joint injections
triamcinolone hexacetonide - local anti-inflammatory effect
typically mixed with hyaluronic acid
a joint injection used in small animals to increase joint viscosity, lubricatio/shock absorption; anti-inflammatory and anabolic effects
hyaluronic acid
joint injection to increase IL-Ra (anti-inflammatory)
cytokine therapy (IRAP)
joint injection where platelts granules rich in Gfs and are anti-inflammatory
Platelet rich plasma
Dog Joint Cytology Analysis : TNCC
Normal:
IMPA:
Infection:
Normal: 2,000
IMPA: 30,000
Infection: 80,000
Meniscal tear rate
50% at presentation with unstable CCL
