Term
| How do bandages aid in wound (soft tissue) healing? |
|
Definition
prevent further contamination of open wounds
debride contaminated and devitalized tissue (wet-to-dry)
maintain a moist wound environment (necessary for normal formation of granulation tissue and re-epithelialization)
reduce swelling and/or hemorrhage (secondary to the pressure exerted by the bandage onto the limb) |
|
|
Term
| How to bandages aid in skeletal healing? |
|
Definition
stabilize the limb
prevent weight bearing (esp. for joint luxation reductions ex. shoulder luxation --> carpal flexion bandage or velpeau sling)
temporary pressure and support to stabilize fractures prior to surgical repair |
|
|
Term
| What bandage management principles should be followed to minimize complications associated with external coaptation? |
|
Definition
AVOID circumferential tape with no elasticity --> acts like a tourniquet (if using non-elastic tape apply like a "barber-poll")
apply the bandage so that just the toenails of the two middle digits (3+4) are visible to monitor for swelling (toe nails spread apart) and to ensure that the leg is not rotated under the bandage/cast (ie. toes not facing forward) <-- this can be minimized by applying the bandage in lateral recumbancy with the affected limb DOWN (hard to do but works as per Pluhar....)
Check bandage daily and change a minimum of once a week |
|
|
Term
| What is the function of the primary bandage layer? What factors influence your decision making regarding which material to use as the primary layer? |
|
Definition
primary layer is in direct contact with the wound. If there is no wound (ex. closed fracture) then a primary layer is not necessary.
Material is chosen based on the amount of exudate, necrosis and contamination present in the wound.
very clean wound (ex. surgical incision) -> non-adherent primary layer (ex. telfa) because we want minimal debridement to facilitate quick healing
lots of contamination and exudate -> wet-to-dry (want to debride all of the devitalized material and transmit the exudate AWAY from the wound into the secondary bandage layer)
large wounds that are minimally contaminated --> adaptive primary layer (ex. gauze + petroleum jelly) to seal the wound from external contamination and maintain a moist environment for granulation tissue development WITHOUT debridement |
|
|
Term
| What is the function of the secondary bandage layer? |
|
Definition
| cast padding or roll cotton (much cheaper, esp. for large bangages like robert jones) ---> absorption of exudate, support and compression |
|
|
Term
| What is the function of the tertiary bandage layer? |
|
Definition
vet wrap and/or elasticon + IV bag for when it's wet outside --> protects bandage and wound from environment, compresses secondary bandage material to provide stability and immobilization (ex. robert jones)
**** remember to tell clients to remove the IV bag when the animal is not outside, otherwise moisture collects within it and it acts like a humidifier (--> skin maceration with decreased barrier function --> risk of secondary infections) |
|
|
Term
| What is a robert jones bandage, when might you choose to use it or choose not to? |
|
Definition
Very large bandage (use 1lb roll cotton per 20lb body weight) that provides temporary compression and stabilization for fractures prior to referral for definitive repair or prior to placing a cast if there is a lot of swelling (otherwise the cast will be too loose once the swelling goes down)
**** DO NOT use for humeral or femoral fractures. Remember, we need to stabilize the joint distal AND proximal to the fracture. It is impossible to immobilize the shoulder or hip with a robert jones bandage. |
|
|
Term
| What are the indications for use of a modified robert jones bandage? What are some of the challenged associated with this type of external coaption? |
|
Definition
same as robert jones but much less padding (secondary layer) --> often used post-op to protect the incision (non-adherent primary layer), reduce swelling, and provide some support
**** Because there is less padding the circumference of the bandage follows the natural shape of the leg (wider at the top and more narrow towards the toes) --> this "funnel" shape makes these bandages very prone to slipping. One way to try to prevent slipping is to add more cast padding to the distal aspect of the leg so that the bandage is the same diameter for the entire limb |
|
|
Term
| How should you apply secondary and tertiary bandage material to the limb? |
|
Definition
| place limb in a functional position, work distal to proximal, maintain constant pressure and apply each layer with 50% overlap over the previous layer |
|
|
Term
| What are three indications for using a splint? |
|
Definition
provide additional stability to a fracture repair or arthrodesis
temporary support after cast or external fixator removal
protect soft tissues of the distal limb (esp. if you've done a skin graft, too much flexion or extension at the graft can cause it to fail) |
|
|
Term
| You can only use cast for fractures in which locations? |
|
Definition
distal to the elbow or stifle
*** remember, just like with the robert jones bandage, we need to immobilize the joints proximal and distal the to fracture. We cannot place a cast to immobilize the shoulder or the hip so we can't use a cast for humeral or femoral fractures |
|
|
Term
| What types of forces can be neutralized by a cast? |
|
Definition
bending and torsion (esp. if spiral fracture because friction along the fracture ends contributes to resistance against torsional forces --> transverse fractures are not stabilized as well with casts alone)
*** NO stability against compressive or tensile forces |
|
|
Term
| What are some disadvantages to using a cast? |
|
Definition
less rigid stability than a surgical repair --> some motion may persist at the fracture site resulting in extended healing time +/- disuse muscle atrophy or fibrosis which could even result in a non-functional limb
limited limb function can result in DJD
requires constant monitoring and frequent changing which can become very expensive |
|
|
Term
| How much secondary bandage material should be applied to a cast? |
|
Definition
only 1 layer --> we want to limit the amount of padding in order to increase the degree of rigid stability
*** so make sure the padding is evenly distributed/not wrinkled --> otherwise pressure sores |
|
|
Term
| What are the pros and cons of using a bivalve cast as opposed to a complete cast? |
|
Definition
| bivalve (ie. cutting the cast in half) facilitates changing but does slightly weaken the stability component of the cast |
|
|
Term
| What five points should be made absolutely clear to any client who is taking home a pet with a cast or bandage? |
|
Definition
check the toes for swelling (separated toenails)
check for loosening/slipping (apply more cast padding to distal limb to prevent, if it's a robert jones bandage slipping indicates that cast/surgery can now be done)
keep clean and dry (IV bags for wet outdoors)
check for foul odors
if the dog starts bothering it (chewing/licking) there's a problem and you need to bring him back in to take off the bandage/cast |
|
|
Term
| What are some complications that can occur in association with external coaption? |
|
Definition
soft tissue swelling (esp. if you use circumferential non-elastic tape)
strike through (not enough secondary material --> strike through allows the wound to get contaminated from the outside in)
cast sores (uneven or wrinkly application of secondary material)
necrosis |
|
|
Term
| What does an ehmer sling do and what are some indications for its use? |
|
Definition
| provides abduction, internal rotation, and a non-weight bearing limb --> for use to maintain a close coxofemoral reduction |
|
|
Term
| What does a 90 degree- 90 degree flexion bandage (aka. Robinson sling) do and what are some indications for its use? |
|
Definition
| maintains the stifle and hock in 90 degree flexion (think tibial thrust position if this helps...) and maintains a non-weight bearing limb --> for use following distal femoral fracture repair to prevent fibrosis of the quadriceps muscle in contraction (occurs if the knee is kept completely extended) |
|
|
Term
| What does a carpal flexion bandage do and what are some indications for its use? |
|
Definition
maintains non weight bearing limb --> for use following closed shoulder reduction
*** results in loss of normal carpal range of motion --> requires physical therapy following removal |
|
|
Term
| What do hobbles do and what are some indications for its use? |
|
Definition
| prevents hip abduction ---> for use following pelvic fracture repair or reduction of ventral coxofemoral luxation |
|
|
Term
| What does an velpeau sling do and what are some indications for its use? |
|
Definition
maintains non-weight bearing limb -> for use following closed reduction of scapular fracture or shoulder luxation
*** results in loss of normal shoulder range of motion --> requires physical therapy following removal |
|
|
Term
| What does a spica splint do and what are some indications for its use? |
|
Definition
| apply rigid material laterally and extending over the dorsal midline for temporary stabilization of humeral or femoral fracture |
|
|
Term
| What is the number one cause of chronic pain in dogs? |
|
Definition
Osteoarthritis (aka DJD)
**** affects 55% of dogs >10 years of age |
|
|
Term
| What is the normal function of the hyaline cartilage in synovial joints? |
|
Definition
distribute joint loads over a wider area
decrease stresses of contacting surfaces
allow relative movement of opposing surfaces with minimal friction and wear |
|
|
Term
| What is the primary protein in hyaline cartilage? |
|
Definition
type II collagen
+ proteoglycans (These are negatively charged proteins that attract water into the cartilage matrix, remember, cartilage is 70% water) |
|
|
Term
| What are the the two types of synoviocytes and what are their functions in maintaining joint heal? |
|
Definition
Type A- phagocytize debris (act like macrophages)
Type B- secrete synovial fluid (to lubrication the joint and nourish the chondrocytes) |
|
|
Term
| What is the pathophysiology of osteoarthritis? |
|
Definition
| mutlifactorial etiology ---> loss of homeostasis between matrix metaloproteinases (MMPs, degredative enzymes) and tissue inhibitors of MMPs results in destruction of proteoglycans and loss of the smooth outer surface (ie. surface fibrilations) PLUS increased density of subchondral bone (sclerosis) --> as the cartilage matrix is degraded chondrocytes release cytokines and other inflammatory mediators which perpetuate the cycle eventually resulting in structural and functional failure of the joint with progressive pain |
|
|
Term
| If osteoarthritis is a chronic progressive disease why do some patients present with acute episodes of pain? |
|
Definition
| Flares of inflammation following changes in normal routine (ie. go for a 5 mile run after sitting around the house for 2 months) result in flares of inflammation --> present clinically as acute pain (can even be non-weight bearing lame) |
|
|
Term
| What physical examination findings are associated with osteoarthritis? |
|
Definition
mild muscle atrophy (disuse)
pain localized to a joint with a thickened capsule, effusion, decreased range of motion +/- crepitus (crunchy feeling secondary to loss of articular cartilage or large osteophytes rubbing across tendons and muscles) |
|
|
Term
| What are the characterisitics of arthrocentesis cytology in a patient with osteoarthritis? |
|
Definition
<1500 cells (most should be monocytes, <10% PMNs)
normal to decreased viscosity (secondary to MMP degredation of hyaluronic acid) |
|
|
Term
| T/F radiographic findings do NOT correlate with clinical disease associated with osteoarthritis |
|
Definition
TRUE
radiographic changes are delayed, a dog may be super lame but if he presents to you early in the disease process there are likely to be no radiographic changes
*** arthroscopy is much more sensitive at detecting cartilage damage than radiographs |
|
|
Term
| In a patients with chronic osteoarthritis what radiographic changes are often appreciable? |
|
Definition
osteo/enthesophyes at the joint capsule and tendon/muscle attachments respectively
intracapsular joint effusion
subchondral sclerosis |
|
|
Term
| What are surgical treatments for osteoarthritis indicated? What surgical treatment options are avialable? |
|
Definition
surgery is a salvage procedure for patients that are not responding to medical management
the main principle in all of the treatments is removal of articular surfaces
a. pseudoarthrosis (femoral head ostectomy)
b. arthrodesis (remove articular surface and fuse joint at a functional angle) <-- best in distal joints with more limited range of motion like the carpus and tarsus
c. total joint replacmenet (hips most commonly but also knees and elbows) <-- result in a joint with increased functionality but risk of implant failure and necessity for removal |
|
|
Term
| What are the three treatment goals for medical management of osteoarthritis? |
|
Definition
relieve pain and discomfort
improve joint range of motion/gait
slow degenerative process and minimize progression (no tx can do this right now unless there is an underlying cause that can be resolved, but stem cell therapy is promising) |
|
|
Term
| What breeds are predisposed to developing hypertrophic osteodystrophy (HOD)? What are the hypothesized etiologies that contribute to the development of this disease? |
|
Definition
great danes and weimeraners
etiology is unknown but is has been proposed that vitamin C deficiency, distemper and e. coli infections, and over supplementation of nutrients and minerals in the diet of a quickly growing breed can all contribute to HOD |
|
|
Term
| What is the proposed pathogenesis of lesions associated with hypertrophic osteodystrophy? |
|
Definition
| disturbances in the metaphyseal blood supply --> failure of normal ossification of the hypertrophic zone of the physis with suppurative inflammation, hemmorhage, and necrosis extending into the metaphyseal trabecular bone --> fractures of the trabecular bone result in lifting of the periosteum with associated periosteal proliferation (appreciable clinically as painful swellings at the metaphyses of the long bones - most commonly the distal radius/ulna) |
|
|
Term
| Describe the clinical presentation of hypertrophic osteodystrophy? |
|
Definition
| young large-giant breed dog with acute onset painful swollen metaphyses (esp. distal radius and ulna) and often non-specific systemic signs (fever, anorexia, depression) |
|
|
Term
| Describe the radiographic findings consistent with hypertrophic osteodystrophy. |
|
Definition
| Uneaven radiolucent zone in the metaphyseal trabecular bone parallel to the physis ("double physis line") + metaphyseal lipping, exostoses (periosteal proliferation), and enostoses (endosteal proliferation) |
|
|
Term
| What is the treatment and prognosis associated with hypertrophic osteodystrophy? |
|
Definition
prognosis is good to excellent for mildly affected individuals as the disease is self limiting once individuals reach skeletal maturity. Provide analgesia with NSAIDs and rest
Prognosis is guarded for severely affected individuals, often associated with concurrent systemic metabolic disease or speticemia, require extensive supportive care (fluids and enteral nutrition) +/- anti-inflammatory doses of steroids and broad spectrum antibiotics if septic. |
|
|
Term
| Although the etiology of panosteitis is unknown there is likely to be a genetic component as ______ breed is overrepresented. |
|
Definition
|
|
Term
| What is the proposed pathogenesis of panosteitis? |
|
Definition
| fat necrosis near the nutrient foramen --> proliferation of stromal cells that produce osteoid --> osteoid deposits spread proximally and distally from the nutrient foramen resulting in further vascular congestion that stimulates secondary enostoses/exostoses --> mottled opacities within the medullary cavity on radiographs |
|
|
Term
| Panosteitis is a self limiting disease affecting young growing dogs. How long after onset of pathology do the lesions resolve? |
|
Definition
3 months
*** medullary trabecular bone is reabsorbed and hematopoietic and fatty marrow elements are re-established. Unlikely to affect the same bone twice. |
|
|
Term
| How does panosteitis present clinically? |
|
Definition
acute shifting limb lameness (affects multiple bones concurrently or sequentially)
pain with direct palpation over affected areas
intermittent fever, lethargy and anorexia (not as severe as in cases of hypertrophic osteodystrophy) |
|
|
Term
| What is the prognosis and treatment for panosteitis? |
|
Definition
prognosis is excellent (this self limiting disease resolves at skeletal maturitiy) however disease course may be protracted as multiple bones are affected.
Tx with NSAIDs and rest |
|
|
Term
| What are the anatomic locations associated with osteochondrosis lesions in dogs? |
|
Definition
shoulder (caudal aspect of the humeral head)
elbow (humeral trochlea)
knee (lateral femoral condyle)
tarsus (medial trochlear ridge of the talus) |
|
|
Term
| Describe the pathophysiology of osteochondrosis. |
|
Definition
| perichondrial vessels (offshoots from the rich blood supply at the metaphysis) supply the epiphyseal cartilage --> disruption of the blood supply to a region of the epiphyseal cartilage results in a region of necrotic cartilage --> if necrotic region is small it becomes fibrotic and enveloped in bone as endochondral ossification progresses....if the necrotic focus is large it does not ossify (appreciable as a lucent defect in the subchondral bone on radiographs) |
|
|
Term
| What two pathologic processes are components of canine hip dysplasia? |
|
Definition
abnormal passive hip laxity (ie. subluxation)
DJD of coxofemoral joint (cartilage damage, osteophyte formation, subchondral sclerosis) |
|
|
Term
| The etiology of canine hip dysplasia is multifactorial, what three factors are thought to contribute to the development of this disease? |
|
Definition
genetics (is. no hip dysplasia in greyhounds but 75% of golden retrievers develop hip dysplasia)
over feeding (if you restrict intake by 25% --> less severe, and later onset of clinical and radiographic disease)
high dietary anion gap
*** it has been postulated that high calcium and protein can contribute to the development of this disease but there is no scientific evidence currently supporting this theory vs. OCD which is associated with high Ca/P ratio |
|
|
Term
| T/F ultrasound is not a good way of identifying canine hip dysplasia |
|
Definition
TRUE - one study showed that this works but NO ONE does it!
**** PennHIP is the best |
|
|
Term
| What are some of the problems associated with using hip extended view (aka OFA) to identify and classify canine hip dysplasia? What is this technique good for? |
|
Definition
good ability to diagnose DJD (less superimposition over the head of the femur than lateral views or PenHIPP)
Poor repeatability of method , poor repeatability of interpretation (re-interpretation will only be the same 50% of the time), not a biologically appropriate view (extending the hind limbs shortens the ligament of the head of the femur which artificially reduces passive laxity), all breeds are considered using the same standards, need to wait until dogs are 2 years of age to assess |
|
|
Term
| Why is the norberg angle measurement not a super informative technique for identifying dogs with hip dysplasia? |
|
Definition
>105 is considered tight, < 90 is considered loose
most dogs are right in between these two values |
|
|
Term
| Why is the norberg angle measurement not a super informative technique for identifying dogs with hip dysplasia? |
|
Definition
>105 is considered tight, < 90 is considered loose
most dogs are right in between these two values |
|
|
Term
| Why is PenHIP the best technique available for diagnosing canine hip dysplasia? |
|
Definition
| excellent ability to diagnose passive hip laxity, excellent repeatability of method and repeatability of interpretation (ie. objective), can predict CHD at 4 months of age (vs. 2 years for OFA) |
|
|
Term
| PennHIP assesses distraction-index based on the breed being tested, why is this important? |
|
Definition
| the distraction index that correlates highly with development of hip dysplasia and DJD differs based on breed. For example, a german shepherd with a distraction index of 0.5 is much more likely to develop DJD than labrador retriever. |
|
|
Term
| Why might a dog with hip dysplasia still have a negative ortolani sign? |
|
Definition
As laxity and DJD progress fibrous connective tissue will build up around the joint capsule to try to increase stability, and this may result in a false negative ortolani test
***** remember, ortolani sign is a test that measures passive laxity - dog is placed in lateral recumbancy, push up (adduct) on the femur --> if too lax it will subluxate --> when you abduct the femur it will pop back into place ***** |
|
|
Term
| What seven treatment options have not been shown to have any scientifically appreciable benefit in the treatment of canine hip dysplasia? |
|
Definition
pectineal myectomy
BOP/shelf arthroplasty
varus/derotational osteotomy
femoral neck lengthening
sacroiliac wedge rotation
acupuncture
cosequin |
|
|
Term
| What medical treatment options are available for the treatment of canine hip dysplasia? |
|
Definition
NSAIDs (cox 2 selective is best - rimadyl, deramaxx, previcox)
Glycosaminoclycans (only Adequan has been shown to have a benefit *in immature dogs*, cosequin has no proven impact)
Daily controlled activity (swimming, leash walks, PT)
Diet (reduce BCS reduce inflammation) |
|
|
Term
| Why even bother with medical management of canine hip dysplasia if there are surgical options available? |
|
Definition
50-80% of dogs managed medically have good clinical function!!
*** remember, medical management consists of NSAIDS, controlled exercise, dietary management +/- adequan if immature |
|
|
Term
| What are the four surgical options for managing canine hip dysplasia, pros and cons? |
|
Definition
femoral head/neck excision (inexpensive, limited function post op <-- only consider as salvage procedure)
triple pelvic osteotomy (95% satisfactory outcome 5 years post-op, slows onset/progression of DJD; however, expensive and small risk of sciatic nerve paralysis, not good choice for dogs with laxity over 20 degrees)
total hip replacement (85-90% positive outcome 5 years post op; expensive, risk of infection and aseptic loosening requiring another big surgery to remove the implant)
pubic symphysiodesis (inexpensive, few potential complications; can only be done in skeletally immature dogs (4-5 months or younger; must be neutered- hip dysplasia is heritable, effectiveness is not entirely elucidated <-- suggested that in patients with moderate to severe hip dysplasia pubic symphysiodesis has similar lack of efficacy as TPO) |
|
|
Term
| T/F Triple pelvic osteotomy must be performed as quickly as possible once hip laxity is identified in order to produce the best outcome |
|
Definition
FALSE
no scientific evidence that pre-operative cartilage lesions or DJD have a negative impact on outcome |
|
|
Term
| What would exclude a dog with hip dysplasia from being a good candidate for triple pelvic osteotomy? |
|
Definition
TPO is not a great option for dogs with severe coxofemoral subluxation
**** 20 degrees or less is the ideal candidate for TPO |
|
|
Term
| T/F Many dogs may have some hip laxity and DJD but will NEVER have any clinical lameness even without therapy |
|
Definition
TRUE
** we treat dogs NOT radiographs! ** |
|
|
Term
| What is the most common cause of lameness in dogs in north america? |
|
Definition
cranial cruciate ligament disease
*** the cranial cruciate ligament is the primary stabilizer of the knee |
|
|
Term
| What are the three major functions of the cranial cruciate ligament? |
|
Definition
prevent stifle hyperextension
limit internal rotation of the tibia on the femur
prevent cranial displacement of tibia on the femur (ie. cranial drawer) |
|
|
Term
| T/F trauma is an uncommon cause of cranial cruciate rupture in dogs |
|
Definition
TRUE
*** etiology is multifactorial (anatomic conformation (hyper-extended or cow hocked stifles), hormonal *associated with sterilization surgeries*, genetic *newfoundlands, rotties and labs are predisposed etc*) |
|
|
Term
| T/F tibial plateau angle is NOT correlated with increased risk of CCL rupture in dogs |
|
Definition
TRUE
** no difference in TPA in labs with CCL rupture vs. those without, no difference in TPA in labs with CCL ruptures vs. greyhounds without (remember, greyhounds are protected breeds) AND the tibial plateau angle in dogs is zero when they're standing |
|
|
Term
| What breeds are protected from cranial cruciate ligament disease? |
|
Definition
greyhounds, doberman pinschers and german shepherds
*** remember, newfoundlands, rottweilers, and labs are at increased risk**** |
|
|
Term
| If there is a genetic component to CCL disease why would instigating a breeding program based on clinical disease alone be ineffective at eliminating the disease? |
|
Definition
| genetic mutations associated with this disease (fibrillin gene in newfies) are expressed with partial penetrance; that is, not all dogs who have the mutation will display clinical signs and in this way you could inadvertently breed carriers that appear clinically normal further perpetuating the mutation within your population of dogs |
|
|
Term
| Why might a dog that has chronic CCL disease present with acute lameness? |
|
Definition
| acute lameness in dogs with chronic CCL disease is often associated with new meniscal tears |
|
|
Term
| What are some physical exam findings associated with CCL disease? |
|
Definition
hindlimb lameness (esp. if unilateral)
medial buttress (thickened joint capsule)
pain on extension of the knee
if complete rupture --> positive cranial drawer and tibial thrust
+/- decreased range of motion (chronic disease with DJD) |
|
|
Term
| What are the anatomic landmarks for placing your hands to perform the cranial drawer test? |
|
Definition
** dog is in lateral recumbency **
place thumb on lateral fabella and index finger on patella
distally play thumb on head of fibula and index finger on the tibial tuberosity |
|
|
Term
| Although ~50% of dogs with CCL disease can be managed satisfactorily with medical management (weight loss, NSAIDs, fatty acids) what aspect of surgical management is most important for controlling pain? |
|
Definition
meniscal release!!!
*** for dogs with partial ruptures or lots of fibrous tissue (ie. medial butress) stabilization may not be necessary to minimize pain |
|
|
Term
| T/F Tibial plateau leveling osteotomy does not provide better stabilization of the stifle joint than the lateral suture technique and is associated with greater patient morbidity and client expense |
|
Definition
|
|
Term
| Which meniscus is more commonly affected in cases of CCL disease in dogs? |
|
Definition
medial <-- the lateral meniscus rarely tears because it only attaches in two places, cranially to the tibia and caudally to the femur. It is not fixed in position to the tibia like the medial meniscus
**** even if grossly normal when you go in to stabilize the stifle, you should always perform a meniscal release because 9-24% of cases will tear later on and present with acute lameness |
|
|
Term
| What signalment is most commonly associated with patellar luxation? In which direction does the patella tend to luxate in these cases? |
|
Definition
toy breeds ---> congenital medial patellar luxation
*** larger breed dogs are more predisposed to develop traumatic patellar luxation --> often luxates laterally. If untreated these patients are predisposed to developing CCL rupture |
|
|
Term
| Which treatment for patellar luxation should never be performed alone? |
|
Definition
| imbrication (ie. pull the patella back into place with suture material) <-- this will fail if you don't make any changes in the bone (ie. trochleoplasty or tibial tuberosity transposition) |
|
|
Term
| How is patellar luxation classified? |
|
Definition
grade 1: no spontaneous luxation but the patella can be pushed out of the trochlear groove
grade 2: luxates spontaneously but remains in the trochlear groove must of the time
grade 3: spontaneously luxated most of the time
grade 4: the patella is always luxated and cannot be replaced into the trochelar groove |
|
|
Term
| What is the most common primary bone tumor of dogs? |
|
Definition
osteosarcoma
*** distal radius is most common location (remember, away from the elbow, near the knee) |
|
|
Term
| T/F although less than 10% of cases of osteosarcoma have radiographically appreciable pulmonary mets at the time of diagnosis most cases do have metastasis at this time |
|
Definition
TRUE
*** negative thoracic rads and/or bone scinitgraphy do not predict increased survival |
|
|
Term
| What is the best kind of biopsy to collect for greatest diagnostic sensitivity for osteosarcoma? |
|
Definition
| large bore sample from the more sclerotic regions of bone |
|
|
Term
| Dogs can better tolerate fore or hindlimb amputation? |
|
Definition
hindlimb
*** smaller breeds may tolerate forelimb amputation but large breeds do NOT do well |
|
|
Term
| Although amputation alone does improve quality of life for dogs with osteosarcoma it does not extend median survival time. What two treatment options are available that will extend MST? |
|
Definition
amputation with chemotherapy (platinum analogs +/- doxorubicin)
or
limb salvage with adjuvant therapy (chemo or radiation) <-- better option for forelimb tumors on large dogs that are not expected to tolerate amputation well |
|
|
Term
| What are four complications associated with limb salvage procedure for treatment osteosarcoma? |
|
Definition
infection
local recurrence of the tumor
lameness (acceptable limb function in 75-80% of cases)
increased expense and patient morbidity with no increase in median survival time |
|
|
Term
| What are the three types of bone grafts? |
|
Definition
osteoinductive: growth factors stimulate angiogenesis and cell diferentiation
osteoconductive: matrix encourages bone growth
osteogenic: osteoblasts and osteocytes are in the graft material |
|
|
Term
| What is the gold standard for bone graft? |
|
Definition
| autogenous cancellous graft (osteoconduction and osteogenesis) |
|
|
Term
| Why would a fracture repaired with a plate and a cortical allograft be more likely to fail than one repaired with a plate and autogenous cancellous bone graft? |
|
Definition
| the cortical bone graft only has osteoconductive capacity and therefore takes much longer to heal --> the bone plate is more likely to fail |
|
|
Term
| What's the difference between arthrodesis and ankylosis? |
|
Definition
arthrodesis <-- you do this by removing the articular surfaces and fusing the joint (salvage procedure for end stage OA)
ankylosis <- nature does this, fusion rarely occurs at a functional angle and it takes a long long time for this to happen after months and years of pain secondary to severe long standing OA |
|
|
Term
| What are the four principles of joint salvage surgery? |
|
Definition
removal of articular cartilage (if you don't remove the cartilage the slow degeneration causes inflammation which impairs boney fusion of the joint)
rigid fixation (place the bone plate on the tension surface of the joint of possible ie. caudal for elbow, cranial for stifle)
anatomic alignment (because you're removing the articular cartilage you have to fix the joint at a slightly straighter angle to maintain the length of the limb)
bone graft (you need to encourage boney fusion of the joint - fresh autogenous cancellous graft is ideal) |
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Term
| What is the prognosis for patients undergoing arthrodesis? |
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Definition
good prognosis for eliminating pain
most patients to have a persistent mechanical lameness |
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Term
| What are some indications for arthrodesis? |
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Definition
| shoulder: congenital luxation or trauma, avoid suprascapular nerve elbow: elbow dysplasia, humeral condylar fractures (do not need to reattach olecranon for triceps function because you're fusing the joint in physiologic flexion) carpus: polyarthritis, grade 3 sprains (hyperextension injuries) stifle: cruciate disease, severe OCD lesions |
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Term
| What are the two alternatives to arthrodesis in vet met? |
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Definition
total joint replacement (hip, knee, elbow)
ablation (femoral head and neck excision) |
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Term
| What should you monitor for your patients on NSAIDs? |
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Definition
monitor for GI signs (ulcers, vomiting, diarrhea) and monitor renal function (esp. if needing to anesthetize as inhalents cause hypotension which impairs renal perfusion)
**** do not need to monitor liver function as idiosyncratic liver failure associated with NSAIDs occurs very acutely and elevated liver enzymes in association with NSAID therapy do not correlate with the development of chronic hepatitis |
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Term
| What is the difference between Cox-1 and Cox-2? |
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Definition
Cox-1 is plays a role in homeostasis of mucosal cytoprotection, platelet aggregation, and renal function
Cox-2 is upregulated in response to inflammation and some elements of fetal development (don't use NSAIDs in pregnant animals) |
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Term
| guess what....you shouldn't mix NSAIDs and steroids |
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Definition
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Term
| Why is asprin especially ulcergenic? |
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Definition
| irreversibly binds to cox-1 receptors inhibiting cytoprotective prostanoid biosynthesis |
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Term
| If you want to switch NSAIDs in you patient that has a history of GI signs while on NSAIDs how should you proceed? |
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Definition
No NSAIDs for 14 days ---> consider cox-2 specific or anti-inflammatory dose of steroids
**** if no history of GI signs 7 day washout for aspirin, no washout necessary for cox-2 specific |
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Term
| What is the most common cause of forelimb lameness in dogs? |
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Definition
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Term
| What breeds are at increased risk for developing ununited anconeal process? |
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Definition
| german shepherds and basset hounds |
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