47.ALD

Question 1

what does CORA stand for

Answer 1

Center of rotation of angulation

Question 2

how is bone alignment objectively assessed

Answer 2

through examination of bone axes (mechanical and anatomical) and joint orientation

Question 3

what is the joint orientation angle

Answer 3

the intersection of a bone axis and a joint orientation line

Question 4

front vs sagittal vs transverse planes

Answer 4

frontal–evaluated on Cr Cd rad–valgus, varussagittal–evaluated on M-L rad–procurvatum, recurvatumtransverse–evaluated axially–torsional malformations6 possible deformities can be presentdeformity is defined by DISTAL portion in relationship to proximal portion

Question 5

define anatomic vs mechanic bone axis

Answer 5

anatomic–line that passes through CENTER or middiaphysis of the bonemechanical–line connecting the center points of the joints proximal and distal to the bone–may be more helpful for sigmoid shape bones (ie. tibia, humerus)–represent weight bearing axis

Question 6

normal mLDHA for large breed nonchondrodystrophic skeletally mature dogs

Answer 6

87 +/- 3 degrees

Question 7

landmarks for proxial radial joint orientation line

Answer 7

proximolateral—radial headproximomedial–medial portion of coronoid process

Question 8

normal procurvatum of the radius

Answer 8

27(study in labradors–sagitttal plane)

Question 9

other joint orientation angles (in frontal and sagittal planes) for proximal and distal radius

Answer 9

proximal close to 90MP (frontal) 83LD (frontal) 86CdP (sagittal) 85CdD (sagittal) 77**procurvatum 27

Question 10

formulation to determine degrees of procurvatum

Answer 10

(90-aCdPRA) + (90-aCdDRA) + thetaTheta is angle creative on sagittal film from intersection of both proximal and distal bone axes

Question 11

difference btwn rotation and torsion

Answer 11

torsion is within the bonerotation refers to motion about a joint

Question 12

proximal joint orientation line of proximal femur landmarks

Answer 12

center of femoral head to the dorsal most aspect of the greater trochanter

Question 13

anatomic bone axis of the femur

Answer 13

determined by a line that connects the points selected at 33% and 50% below the proximal aspect of the femoral neck in the middle of the femur

Question 14

T/Fthe anatomic bone axis will deviate from the center of the bone in the femur

Answer 14

TRUEthe anatomic bone axis will deviate from the center of the bone in the femur because NORMAL femoral VARUS (ends just lateral to the intercondylar notch)

Question 15

mechanical axis of the femur

Answer 15

line from center of femoral head to center of the distal femoral joint orientation line

Question 16

angle of anteversion

Answer 16

measured on CT or axial radiographangle btwn the neck and the frontal plane described by the caudal aspect of the femoral condyles~27 (range 16-31.3)

Question 17

angle of inclination

Answer 17

measure on frontal radiographangle formed by the proximal femoral anatomic axis and a line that originates at the center of the femoral headcoxa vara—decreasedcoxa valgus–increasedN GSD 132N LABS, GOLDENS 134N ROTTS 137

Question 18

proximal and distal, lateral anatomic and mechanical joint axes of the femur

Answer 18

> 90 but < 100 degrees

Question 19

T/Fmechanical bone axis is used in the tibia

Answer 19

TRUE due to sigmoid shape

Question 20

proximal tibial angle is reciprocal of what joint angle

Answer 20

proximal tibial angle is reciprocal ofmCdPTAnormal values vary 24-26

Question 21

torsion of > 15 degrees results in how much miscalculation of a frontal plane deformity

Answer 21

torsion > 15 degrees will result in miscalculation of up to 5 degrees of a frontal plane deformity

Question 22

surgical planning for CORA based corrections

Answer 22

–know normals axes and joint angles of good leg–rads, CT, stereolithography–locate CORA–define plane of deformity (uniplanar, biplanar)–define magnitude CORA–locate osteotomy–angulation correction axis

Question 23

T/Fthe magnitude of the CORA equates to the degree of correction required to eliminate the deformity

Answer 23

TRUE

Question 24

T/FThe plane of the CORA is ALWAYS in the direction OPPOSITE of how the bone is deviated

Answer 24

TRUE plane of the CORA is ALWAYS in the direction OPPOSITE of how the bone is deviatedpur frontal deformity with valgus (lateral deviation of dotal portion) then the plane of deformity is medial

Question 25

partially compensated vs NONcompensated CORA

Answer 25

applies to BIAPICAL deformities (2 CORAs present)partially compensated–both CORAs with planes in the OPPOSITE directionnoncompensated–both CORAs with planes in the SAME direction

Question 26

what is a translational deformity

Answer 26

when no angulation is present but the proximal and distal segments are NOT co-linear but rather shifted relative to one another

Question 27

what is the angulation correction axis

Answer 27

the hinge point upon which rotation of two segments of bone can be madealways possesses a PERPENDICULAR relationship to the plane of the deformity

Question 28

palsy’s three rules of osteotomies

Answer 28

1. osteotomy and angular correction axis are co-linear with CORA–realignment occurs2. osteotomy is achieved at a different location than angular correction axis which is based on CORA–translation occurs (ex. TPLO, junta-articular corrections) but still co-linear3. osteotomy and angular correction axis is at a different spot from CORA–translation and NOT co-linear

Question 29

types of osteotomies for correction of ALD

Answer 29

1. opening wedge (osteotomy)2. closing wedge (ostectomy)3. radial (cylindrical)–match blade diameter to bone diameter3. true dome–size matched blade to widest dimension

Question 30

on what side of the bone is an opening CORA vs a closing CORA

Answer 30

Neutral CORA is where intersecting axes are formedbut really the CORA is made up a infinite CORAs along the transverse bisecting lineconvex side CORA–opening CORAconcave side CORA–closing CORA

Question 31

T/Ftrue dome osteotomies correct deformities in all three planes

Answer 31

TRUEtrue dome osteotomies correct deformities in all three planesradial(cylindrical) only corrects in one plane

Question 32

types of fixation following ALD corrective osteotomies

Answer 32

–internal fix bone plate (often with closing wedge to have load sharing); compression vs locking plates–linear ESF (need robust designs for opening wedge)–circular, hybrids ESF (good for juxta-articular deformities)