PELVIS, HIP: 56, 57, 58, 59

Question 1

How many fracture configuration can be seen in pelvic fractures?

Answer 1

160 total, with 19 repeatedly observed (in 52% of all cases)

Question 2

anatomy of the lumbosacral trunk

Answer 2

it becomes the sciatic nerve after being joined by the 2° sacral nerve, and passing over the greater ischiatic notch and exit the greater ischiatic foramen

Question 3

percentage of recovery of animal with peripheral nerve injury

Answer 3

15% had permanent loss of linb function

Question 4

Pelvic canal ratio

Answer 4

hamilton 2009. A-B= cranial border sacrum
C-D= medial cortex acetabulum. 0.97 +- 0.025 in normal cats.

reduction of <10% mild, 10-30% moderate, >30% severe

Question 5

typical pattern for ilium fractures

Answer 5

from cranioventral to caudodorsal, immediately caudal to the sacroiliac joint

Question 6

position of the lumbosacral trunk in respect to the ilium body

Answer 6

medial and dorsal

Question 7

in lateral plating of the ilium, where does screws tipically pull out?

Answer 7

cranial fracture segment

Question 8

acetabular fractures classification

Answer 8

simple, transverse, oblique or comminuted

location: cranial, dorsal, caudal, central

Question 9

prevalence of unilateral and bilateral SI luxation fracture

Answer 9

77% unilateral, 23% bilateral

Question 10

do cats have a sacral notch?

Answer 10

only 34% of cats and 98% of dogs

Question 11

screw loosening in SI luxation with screw >60% width sacrum

Answer 11

7%

Question 12

classification of sacral fractures Anderson 1997

Answer 12

1) alar
2) foraminal
3) transverse
4) avulsion
5) comminuted

Question 13

most common pelvic fractures?

Answer 13

pelvic fractures

Question 14

name the primary stabilizers of the hip joint

Answer 14

1) ligament of the head of the femur
2) joint capsule
3) dorsal acetabular rim

Question 15

incidence of femural luxation on all luxation

Answer 15

90%

Question 16

what percentage of femural luxation are craniodorsal?

Answer 16

75%

Question 17

incidence of relaxation after closed reduction of COX-FEM luxation

Answer 17

more than 50%

Question 18

name 5 techniques for augmentation of closed reduction

Answer 18

1) Ehmer sling: 10 to 14 days, relaxation 15-71%
2) Hobbles
3) Ischioilial pinning: 2-4 weeks
4) External skeletal fixators
5) transarticular pinning

Question 19

median success rate after open reduction

Answer 19

+- 85%

Question 20

Name 12 procedures for open reduction

Answer 20

1) capsulorraphy
2) prostethic capsule repair
3) transposition of the greater trochanter
4) transarticular pinning
5) toggle rod: 6% relaxation
6) fascia lat loop stabilization
7) transposition of the sacrotuberous ligament
8) extra-articular iliofemoral suture
9) surgical stabilization of ventral luxation
10) femoral head and neck excision
11) TPO/DPO
12) THR

Question 21

caudal acetabular fractures should always be managed conservatively. T or F

Answer 21

F. caudal acetabulum has weightbearing load. without intervention faster progression to osteoarthritis

Question 22

what is the main responsible to maintain hip joint stability during the first months of life?

Answer 22

ligament head of the femur

Question 23

breifly describe the 2 biomechanic principles associated with funcional subluxation of the hip

Answer 23

1) forces crossing the joint increase
2) area over wich the forces are transmitted decreases

Question 24

lower cutoff value for Distraction Index

Answer 24

0.3

Question 25

Name all the proposed factors that can lead to hip joint laxity

Answer 25

1) joint fluid 2) pelvic muscle mass 3) hormonal factors 4) weight and growth 5) nutrition 6) environmental 7) other

Question 26

pectineal myectomy or tenotomy reduces incidence of hip displasia. T or F

Answer 26

F

Question 26

progression of osteoarthritis lead to thightening of the capsule. T or F

Answer 26

False. greater osteoarthritis = greates laxity.

Question 27

all dogs with hip displasia have a wide based stance. T or F

Answer 27

F: initially wide stance to help with hip reduction. As it progresses, develop narrow-base to degrease discomfort caused by reduction and then subluxation.

Question 28

Negative Ortolani test is highly indicative of a sound hip. T or F

Answer 28

F: 50 % ortolani negative had hip joint laxity measured by DI

Question 29

what sign can be confused with a morgan's line (caudolateral curvilinear osteophyte) ?

Answer 29

puppy line. same position, but shorter, more diffuse, more subtle. Younger than 18 MO, self limiting.

Question 30

distraction index always correlate with both ortolani sign. T or F

Answer 30

F: the presence of osteoarthritis weaken the correlation. 50% dogs with DI >0.3 had normal ortolani.

Question 31

ultrasonography of the hip has an high rate of false.......

Answer 31

positive. results in overtreatement in children.

Question 32

name 3 main cons of ultrasound for early diagnosisi of hip displasia

Answer 32

1) subjectivity/imprecision in repeated measurements 2) absence of reference ranges 3) variables at 16-49 days do not correlate with diagnosis of Hip displasya at 12 to 24 months.

Question 33

theorical characteristics of the ideal hip screening tool

Answer 33

1) accurately identify unwanted phenotype (es. hip extended, norberg do NOT correlate with OA progression) 2) interobserver reliability 3) continuous ratio scale; not intervals 4) early diagnosis 5) valuable tool for estimate breeding value (must have an hereditary component) 6) selection pressure: genetic change towards better hips.

Question 34

Mass selection (evaluate just the individual phenotype) is adequate for highly or lower geritable traits?

Answer 34

highly! (>0.5). as it decrease (<0.35), increasingly important to consider relative's phenotype

Question 35

anatomic caracteristics of pelvic symphysis

Answer 35

is a synchondrosis that trasforms in synostosis

Question 36

time to ossification of pelvic symphysis

Answer 36

2-6 years (fibrocartilage replaced by bone)

Question 37

age at wich greatest changes in acetabular coverage is seen with JPS

Answer 37

12 W

Question 38

what muscles need to be retracted from pubic sympyhysis?

Answer 38

gracilis and adductor

Question 39

Gatineau correlation between reduction angle and development of OA: angle?

Answer 39

less than 15° less chances of developing OA

Question 40

surgical approach to the pubis

Answer 40

1) pectineus muscle 2) iliopectineal eminence palpable cranially, avoid deeper medial circumflex femural artery 3) elevate periosteum from cranial (IP eminence to caudal (obturator foramen) 4) osteotomy

Question 41

approach to ischium for ischial osteotomy

Answer 41

1) dorsal incision 2) elevation internal obturator dosally, avoid pudendal nerve 3) ventral elevation semim, semit, internal obturator (to evaluate complete cut

Question 42

the sacroiliac ligament may remain attacched to caudal iliac segment when....

Answer 42

osteotomy is performed perpendicular to iliac body. Better to perform osteotomy perpendicular to long axis pelvis

Question 43

rate of screw losening following DPO

Answer 43

3.2%

Question 43

rate of screw losening for Locking Pelvic osteotomies plates

Answer 43

0.4%

Question 44

what is stress shielding and what does it causes

Answer 44

a) implant stiffer than bone b) bone resorption (result of disuse atrophy)

Question 45

what is the primary cause of aseptic losening?

Answer 45

wear debris

Question 46

How it's called the science that studies bearing surfaces/friction lubrication articular surfaces?

Answer 46

Tribology

Question 46

name the various types of wear experienced by a prostethic component

Answer 46

1) adhesive wear 2) abrasive wear 3) Fatigue wear 4) erosive wear 5) impingement wear 6) corrosive wear

Question 47

Ceramic has a similar elastic modulus than bone T or F

Answer 47

F: almost 300 greater than cancellous bone. Backing with metal to prevent aseptic losening secondary to modulus mismatch

Question 48

Articulations combinations available in veterinary and lowest wear rates

Answer 48

1) vet only available metal on polyethylene 2) lower wear ceramic on ceramic.

Question 49

ideal micromotion to allow bone ingrowth (osseointegration)

Answer 49

below 20 um. (over 150 um fibrous interface will develop).

Question 50

benefit of hydroxiapatite

Answer 50

1) osteoconductive 2) calcium phosphate base 3) prevent migration of wear debris

Question 51

normal hip joint extension and flexion angles

Answer 51

148 ; 118 °

Question 52

the greater the jumping --> lower is the resistance to luxation lower production of wear debris T or F

Answer 52

F: greater distance femural head must trave befor luxation occur --> higher resistance to luxation, increased production of wear debris

Question 53

name the 3 descriptors of acetabular component placement

Answer 53

1) version (15-20°) 2) angle of lateral opening 3) inclination

Question 54

what should happen in acetabulum of severe osteoarthritis hips

Answer 54

false medial acetabular wall

Question 55

forms of biological failure

Answer 55

A) aseptic loosening B) septic loosening C) stress protection

Question 56

Hayes found an higer rate of luxation in luxoid hips treated with THR. T or F

Answer 56

F. acetabular depth ratio associated.

Question 57

Vancouver classification of femur following THR

Answer 57

-Ag and Al: greater and lesser throcanter -B1,2,3: fractures involving prosthesis (b1 stable, others unstable) -C: distal to prosthesis

Question 58

pulmonary emboli has similar rates in press fit and Zurich THR. T or F

Answer 58

F. 82% cemented press fit (Liska); 0/11 Zurich