New Material for final Flashcards
What do JPS, TPO and DPO have in common?
They are surgeries that modify the hip biomechanics and development in growing dogs
-to stop subluxation tendency
-to restore hip congruency and save the joint from OA development
-should be done before OA progression so there is a very narrow time window
-must be diagnosed early
Is hip dysplasia usually unilateral or bilateral?
Bilateral
What is the difference between subluxation, luxation, and dislocation?
Subluxation: there is articular to articular contact and surrounding joint capsule and musculature are intact
Luxation: there is no articular to articular contact, but joint muscle and surrounding musculature is intact
Dislocation: no articular to articular contact, joint and surrounding musculature not intact (usually due to trauma)
Define congruency
How well the joint fits together
Define hip dysplasia
Abnormal development of the hip joint leading to poor congruency
What is the biggest factor that influences skeletal maturity in dogs?
Age of spaying/neutering
-best time from orthopedic standpoint is 2 years of age
With joint laxity, what is the age in which OA will start to develop without intervention?
7 months
What causes laxity in young dogs?
Bone growing quicker than the surrounding musculature
-worsens with neutering
Describe the features of the juvenile pubic symphysiodesis (JPS) procedure.
-must be done at 3-5 months of age
-cauterization and subsequent fusion of the pubic symphysis causes acetabulum to grow medial and ventral, improving both coverage and congruency (more important)
-performed prophylactically (preventatively)
Why is JPS not very popular?
-done before clinical signs
-many owners aren’t knowledgeable enough to know about this
-best done between 12-17 weeks of age (very specific time period)
When should JPS be recommended?
As soon as early diagnosis is reliable:
- 3.5-4 months of age
-4.5-5 months of age for giant breeds
What used to be the most reliable view for hip radiographs to assess congruency in dogs?
OFA- must include cranial to ilial wings and distally must include stifle
- animals have to be a minimum of 2 years of age for these films to be considered
Describe the Penn Hip
Measure center of acetabulum and femoral head to find distance (distractive index)
- numbers are very reliable
-can be done at a young age(16 weeks)
-any practitioner can do this after taking online course
- if distractive index above a certain value, the probability of the dog having hip dysplasia is low
What is measuring ortalani?
measuring the angle of subluxation (degree of abduction where the femur comes out of acetabulum)
What are the criteria for JPS being indicated?
-penn hipp shows high probability of hip dysplasia
-3.5-4.5 months of age (breed variation)
-Ortolani sign (evidence of laxity)
-angle of reduction 15-40 degrees
-angle of subluxation 0-10 degrees
-dorsal acetabular rim angle up to 12 degrees with no DAR erosion
-DI between 0.4-0.7
-no clinical signs (but high probability due to the above)
Where do you cut for JPS?
Where spay incision ends, just cranial to pubis
- protect the abdominal organs with wooden spatula (especially the urethra)
-cauterize cranial part of pelvic symphysis
What are the ethical concerns associated with JPS?
-the dogs undergoing this procedure had a chance of not developing hip dysplasia
-might pass for breeding
What are the radiographic changes that occur after a JPS procedure?
-pubic symphysis fusion
-broader and short pubic rami
-widened obturator foramina
-irregular pubic profile
-detectable acetabular fossae (most prominent feature)
What are the potential complications associated with JPS?
-urethral damage (<5% of cases)
-skin burns due to electrocautery (dog needs to be grounded properly)
-lack of efficacy (wrong selection or wrong procedure)
-ethical consequences
T/F: JPS is ineffective in dogs with more severe clinical and radiographic changes
True
What is the purpose of the TPO and DPO procedures?
Corrective pelvic osteotomies in dogs with the purpose of arresting hip dysplasia in the early stages of the disease
What is cut during a TPO procedure?
-Body of ileum just caudal to the sacrum
-pubic ostectomy
-ischial osteotomy
What is cut during a DPO?
-pubic ostectomy
-osteotomy of ileal body just caudal to sacrum
-dont touch ischium- relying on immature bone of dog
-wont be able to rotate the pelvis as much as TPO
Why is TPO falling out of fashion?
-too many complications (implant loosening common)
-high morbidity due to cutting of ischium
-results in pelvic narrowing and excessive head coverage
-makes total hip more difficult
How should the iliac osteotomy be performed in a DPO?
-as close to the iliosacral joint as possible
-use oscillating saw or sharp osteotome (not as good)
-minimally invasive technique
-make cut perpendicular to long axis of pelvis, not long axis of ileal body (results in better bone to bone contact)
What arteries need to be avoided when performing a DPO procedure?
Iliacus artery and cranial gluteal artery
-also need to avoid lumbosacral trunk on medial side
What are the benefits of locking screws with a DPO surgery?
Stronger fixation of the plate and screws
What was the main problem that occurred with the TPO?
Tendency was to overcorrect
-too much rotation lead to excessive femoral head coverage
-causes dog to walk like a duck
-also causes severe narrowing of the pelvic canal
What is the morbidity associated with DPO?
-dogs often up and walking 2-8 hours after surgery
-with bilateral DPO there is a risk of obstructing the urethra
T/F: It is still beneficial to perform a DPO after 7 months
False- you can improve coverage but not congruency which is the most important part
Why are DPOs uncommonly done?
Not enough surgeons
-no one wants to do them because of the potential complications
The only reason this is done is if your out of the window for JPS
Describe some clinical features of patellar luxation
-many different causes, therefore each case needs individual evaluation
-PL is the clinical manifestation of an underlying disease, not a disease itself
-pathophysiology of PL is due to limb deformity that results in a misaligned quadriceps mechanism (deformity of the hip in most cases)
-any treatment plan must address the underlying problem
T/F: the rectus femoris is the only muscle of the quadriceps that does not originate from the proximal femur
True
What are the different grades of patellar luxation?
Normal: alignment of the quadriceps mechanism is normal and patella cannot be luxated from groove
Grade 1: patella can be luxated medially when joint is in full extension. Clinical signs are typically absent
Grade 2: spontaneous luxation occurs with non-painful “skipping” lameness, mild skeletal deformities are present
Grade 3: patella is luxated permanently but can be reduced, more severe bony deformities present
Grade 4: permanent non-reducible luxation of the patella
What is patella laxity?
When patella can be moved, but stays within the trochlear ridge
-NOT a luxation
What side is the patella usually luxated to?
Medially in both small and large breed dogs
-if it is a lateral, more likely to be seen in large dogs
What are the treatment options for the bony tissue in a patellar luxation?
Trochleoplasty- deep or modify trochlear groove
Patelloplasty -remove osteophyte and reshape
Patellar lowering or raising (if alta or baja)
Distal femoral osteotomy for valgus and varus cases and torsion
Tibial tuberosity transposition (TTT): should be done in every case
Proximal tibial osteotomy: if grade 3,4 with valgus/varus
Femoral trochlear prosthesis
Total knee prosthesis/arthrodesis
What has to be done to the soft tissues in patellar luxation cases?
Capsulorrhaphy (modifying the joint capsule)
Ispilateral retinacular and joint capsule desmotomy
Release f the medial crural fascia for MPL
Transposition or release of the rectus femoris origin for MPL
Describe the block resection trochleoplasty
Deepening of the trochlear groove proximally
-helps patella track more naturally
Complications: will lead to OA, can fracture the trochlear ridge or the block, can make it too thin
Describe the patelloplasty
-adapts the patellar shape to the trochlear groove
-performed with bone rasp or osteotome
-important to expose the articular surface of the patella and check for osteophytes, erosions or widening
-ultimate goal is to remove pain in order to encourage animal to use and build up the quadriceps
-only a temporary fix
Describe the tibial tuberosity transposition
-move in opposite direction of the luxation
-controversial in skeletally immature patients due to arresting of the physis
What do you do during the capsulorrhaphy/desmotomy?
-release the medial patellar ligament and imbricate the lateral for a medial luxation
-use horizontal mattress to pull the patellar laterally
What is the best you can hope for with surgery to correct patellar luxation?
Improvement by one lameness grade and one luxation grade
-why early diagnosis and treatment is so important before they get worse
What disease often occurs concurrently with patellar luxation?
CCL disease
What abnormalities are usually present with medial vs lateral patellar luxation?
Femur:
- Medial: distal varus, external torsion
- Lateral: distal valgus, internal torsion
Tibia:
- Medial or lateral : internal or external torsion
Patella:
- Medial: alta
- Lateral: Baja
When should you perform a Patellar Groove Replacement (PGR)?
When existing treatment modalities are at their limit when confronted with severe patellofemoral DJD
-or when there is agenesis of the trochlear ridge and patient is skeletally mature
T/F: Heat drives degenerative changes
True
T/F: PGR corrects for patellar luxation
False
- it is to reduce pain, but you need the other alignment procedures to correct for the luxation
-recommended in older painful animals with severe DJD
Describe the contraindications for trochleoplasty
-chronic and severe patellar luxation
-severe osteophytosis
-severe loss of joint cartilage
-revisions of failed previous surgery
-severe malformation of the trochlea
-presence of trochlear ridge fracture (challenging to repair)
-convex trochlear groove with congenital patellar luxation
These also make an animal a candidate for trochlear groove replacement
What is the procedure that corrects for malalignment?
TTT
- with grade 3 and grade 4 also add in distal femoral osteotomy to address valgus/varus
What are the 4 layers of the esophagus?
Adventitia, Muscularis, Submucosa, Mucosa
*note- no serosa
Where would you cut to approach the different areas of the esophagus?
Cervical: ventral midline
Thoracic: Thoracotomy
Abdominal: ventral midline celiotomy
What are the main surgical principles that need to be considered when working with the esophagus?
Gentle tissue handling, minimize contamination, appropriate use of suture materials, judicious use of electrocautery, accurate apposition of tissues
-generally the esophagus is associated with a higher instance of complications, especially dehiscence
Why is the esophagus more prone to dehiscence?
Lack of serosa, segmental blood supply, lack of omentum, and constant motion
What suture do you want to use when operating on the esophagus?
Monofilament, minimally reactive, slowly absorbable suture(aka PDS)
-two layer closure is ideal (submucosal first, then all layers)
What is the difference between an esophagotomy, esophagectomy, and esophagostomy?
Esophagotomy: creating an opening into the esophagus that is later closed
Esophagectomy: removal of a portion of the esophagus
Esophagostomy: creating an opening- can be temporary or permanent
Describe a vascular ring anomaly.
Congenital anomaly where aortic branches persist and cause constriction around the esophagus
How would you approach a vascular ring anomaly surgically?
4th rib space thoracotomy in dogs, 5th in cats
- identify the anomaly and transect it
-ligate as there may be vessels that live within it
What is a GI condition that often goes along with brachycephalic syndrome?
Hiatal Hernias
What are the 4 types of hiatal hernias?
Type 1: gastroesophageal junction moving orally into the chest
Type 2: a part of the fundus herniates between abdominal esophagus and through hiatus
Type 3: combo of type 1 and 2
Type 4: Another organ moves up through the hiatus into the chest
What are the surgical treatment options for hiatal hernias? What potential complications exist with these procedures?
Phrenoplasty (reduction of hiatus)
Esophagopexy (to diaphragm)
Left gastropexy (to body wall) of the fundus
Complications: may narrow esophagus leading to obstruction
-persistent regurgitation due to esophagitis, re-herniation or hiatus over-reduction
What can you do to remove a foreign body in the esophagus?
Endoscopy or gastrotomy (for caudal cases), orogastric tube placement to push foreign body into the stomach to hopefully pass it (preferred over surgery)
-surgery would be indicated if the airway is compromised or the viability of the intestine is questionable
What arteries provide the main blood supply to the stomach?
Right and left gastric artery on lesser curvature
Gastroepiploics on greater curvature that give off the short gastrics
What are the surgeries that are commonly performed on the stomach?
Gastrotomy, partial gastrectomy, gastropexy, gastrostomy tube placement
What is the difference between the cushings and connell suture patterns?
Connell is full thickness (l for entering lumen), cushings is partial thickness
What is the radiographic view to diagnose GVD?
RIGHT LATERAL
Is one reading of high lactate a poor prognostic indicator?
No- need serial lactates
What is the first thing you will see upon ventral midline celiotomy in a GDV case?
Omental drape
