Musculoskeletal Flashcards

Question

Name parts of muscle

Answer 1

Z-band A-band = conjoined myosin fibers I-band = centerd on z disc and actin fibers

Answer 2

Action potential → acetylcholine released → binds sarcolemma and depolarizes causing Ca release from sarcoplasmic reticulum → confrom change in tropmyosin exposes myosin site on actin → globular head myosin filament engages with ATP → shorten sarcomere

Answer 3

**Epimysium:** fasicles assembed to mm. bellies **Perimysium**: Fibers into fasicles **Endomysium**: myofibers into fibers (**satellite cells** = myoblastic progenitor cells) basement membrane basis of ECM in each layer: Composed of nerves, vessels, lymphatics, Type 1 collagen, proteglycans, fibroblasts ECM \<10% skeletal m ECM provides structure for force transfer and elastic recoil

Answer 4

Type 1 = slow twitch = mitochondria rich, sustained low velocity, low force (oxidative metabolism) = improved aerobic capcity, stimulated by prolonged low levels force Type 2 = fast twitch = few mitochondria, rich in myofibrils, transient high velocity and force = high intesity conditioning = hypertrophy type 2, synthesis myofibril proteins, enlarment and increase contractile capabilites

Answer 5

Visoelastic = strength depends on the rate the bone loaded (bone stronger when rapidly loaded) Anisotropic = mechanical properties depend on the direction of loading

Answer 6

Stress = N/m^2 = newton/ meter squared Stain = local deformation = L1-L2 / L1 Illustration of stress (A) and strain (B). A, Force (F) is applied to a block, producing stress (σ). When the surface area is decreased by one half, the stress is doubled (2σ) for the same amount of force. B, The mathematical definition of strain is the change in length divided by the original length

Answer 7

Strength = load material can withstand before failure Stiffness = rate at which material deforms with load

Answer 8

Illustration of a stress/strain curve produced when a material is loaded. The slope of the ascending linear portion of the curve is the **stiffness** of the material. Point Y is the yield point of the material. Point U is the ultimate strength of the material. **Toughness** is defined as the area under the curve (red shading)

Answer 9

Porosity (volume open space to bone): cortical 5-10%, cancellous 75-95% Cortical bone short plastic phase, cancellous bone long plastic phase Cortical bone higher stiffness and strength Total energy absorbed can be greater for cancellous due to prolonged plastic phase Note the prolonged plateau in cancellous loading representing the collapse of trabeculae.

Answer 10

Cantilever = break at fixation point 3-point = break at middle force (where bending point present) 4 point = constant loads between middle points moment = tendency of a force to twist or rotate an object, expressed in units of torque Illustration of bending moment diagrams for various loading conditions. A, Pure bending when opposite torques are applied to each end of a beam. B, Cantilever bending with an applied load at the end of a beam. C, Three-point bending with two equal loads applied at each end and a third load applied between them. D, Four-point bending with two equal loads applied at each end and two additional loads applied between them

Answer 11

Compressive = oblique fracture tensile and bending = transverse bending with compression = butterfly fragment torsional = spiral

Answer 12

Primary gap healing. A, The gap is initially filled with transversely oriented lamellar bone. B, A cutting cone moves across the lamellar bone, producing osteoid that is mineralized to form longitudinally oriented lamellar bone. This process is known as longitudinal Haversian remodeling Occurs when gap \<1mm, Strain \<2% * Lamellar bone forms in gap early = Deposited within days, No cartilage intermediary, Transverse orientation, Little stability * 3rd week of healing = Longitudinal remodeling = Osteons (with osteoprogenitor cells) cross gap, Longitudinally oriented osteons placed (still weak) * By 8 weeks = secondary remodelling = Similar to contact healing cascade

Answer 13

A, Because of direct contact with bone ends, lamellar bone is not formed transversely. Cutting cones cross the fracture line directly and form new longitudinally oriented lamellar bone. B, Mature osteons cross the original fracture site, connecting the segments and providing strength to completely repaired bone

Answer 14

Plt-rich hematoma formation - Release of TNF-α, IL-1, IL-6 - MSC release from soft tissues, periosteum, bone marrow - BMPs induce proliferation and differentiation of MSCs - Granulation tissue replaces hematoma - Angiogenesis (VEGF, angiopoietin) - Hard callus (woven bone) forms by intramembranous ossification from cambium layer of periosteum - Fracture gap bridges by soft callus - Endochondral ossification replaces soft callus with bone - Remodelling: hard callus replaces with lamellar bone

Answer 15

Endrochondral ossification (cartilagenous precusor) Intramembranous (direct differentiation of mesenchymal cells to ostoblasts) - how flat bones formed, compaction of trabeculae to cortical bone Direct (no evidence of callus) Indirect aka secondary bone healing

Answer 16

Granulation / hematoma up to 100% - 40 degrees Fibrous tissue 20% Cartilage 15% Fibrocartilage 10% - 5 degrees Woven bone \< 10% lammelar Bone \<2% - 0.5 degrees

Answer 17

regnerate bone via intramembranous ossification - fibrous interzone (central radiolucent zone) = once distraction stops the zone mineralizes During distraction osteogenesis, osteoid is laid down in parallel columns that extend from osteotomy surfaces centrally. Lamellar bone develops within these columns if the fracture is sufficiently stable

Answer 18

60% agreement Type 1: Open fracture with wound \<1cm, soft tissues mild/mod contused, usually inside out Type 2: wound \>1cm w/o extensive soft tissue damage, flaps or alvusions, usually from outside Type 3: extensive soft tissue damage 3a = adequate soft tissue coverage despite extensive trauma 3b = extensive soft tissue loss, periosteal stripping, bone expsoure, usually massive contamination 3c = associated with arterial injury requiring repair

Answer 19

Each given subscore of 1, 2, or 3 for mild, mod or severe S-skin defect M- muscle injury A- arterial injury B - bone injury C- contamination SMABC = M-CABS

Answer 20

Lack abx resistent organisms too much time from injurgy to starting abx extensive soft tissue trauma positive port-debridement/irrigatation culture

Answer 21

human: within 3 hours = 4.7% vs 7.4% for +4 hours Type 1 and 2 fractures: ~6% with fluoroquinolone or cephalsporin/gentamycin = rec. 1st/2nd gen cephalporin Type 3: 7.7% with ceph/genta vs. 31% with cipro = rec. ceph + fluoro Common = staph, strep, kleb, pseudomonas, clostridium, enterobacter, e. coli abx beads = decreased from 12% to 3.7%

Answer 22

Human studies no difference, old dogma = debride within 6 hr

Answer 23

Decreased interstitial edema Increased blood flow Accelerate formaiton of granulation tissue increased bacterial clearence promotes wound contraction secure skin graft

Answer 24

Cancellous is safe Cortical = risk for infection/sequestum formation

Answer 25

Type 1 = 0-5% Type 2 = 1-14% Type 3 = 2-37%

Answer 26

related to cross-sectional area π x r^2

Answer 27

Peak load = twist knot superior Tension lower twist (70N vs 165N single loop) but similar load to losening (268N vs 259N loop) double loop more tension (391N) and higher load to losening (661N) Resting tension drops \<30N after collapse of only 1%

Answer 28

at least 2 wires space 1/2 bone diameter apart shaft completely rebuilt

Answer 29

0.035mm 0.045mm 0.062mm

Answer 30

Area moment of inertia = r ^4 Stiffness also influenced by the length of the pin (shorter = stiffer)

Answer 31

70% when pin is used as only intramedullary device

Answer 32

self locking and self centering

Answer 33

Placed neutral axis of bone = direct axial compression Large AMI = more resistence to bending - nail AMI = r^4 vs plate AMI = thickness ^3 (aka 8mm nail AMI 6.8x 3.5mm DCP plate) Locking mechanism = stability in torsion and compression

Answer 34

Weakest when bending parallel to the long axis of the screw - screw holes concentrate stress, small hole = stronger nail (3.5mm to 2.7mm in 6mm nail = 52x increase in nail fatigue life) Plate rod may be biomechanically superior (ILN more slack in bending and torsion - upto 33 degrees) Rotational instability = nonhealing rate of 14% for 2nd gen ILN

Answer 35

Bolts not scews Placement of IM pin with ILN Excessive angling of screws Use of bolts attached to ESF

Answer 36

ASLIN elminates all slack in bending (both planes) and **torsion** - ASLIN smaller maximal deformation, 50% deformation in ILN due to slack --- ASLIN stable directly after sx - ASLIN decreases interfragmentary motion Titanium ILN increased stiffness, strength in torsion, compression and bending Lower lameness scores at 8w Clinical union at 8-10w vs. 12-18w (stiffer/stronger under torsion = calus matured faster)

Answer 37

**Dynamic mode** = need axial loading bc only secured to 1 fragment - minmal resistence to rotation, locking prevents migration, associated with prolonged healing and the need for removal of locking device but potential for increased micromotion and healing **Stable mode** - can be destabilized at 6-10w Non-Reaming of the canal associated with less infection, fat metabolism and histological more rapid healing.

Answer 38

Examples of interlocking nail systems. Regular interlocking nail attached to extension piece and aiming device; drill bit is placed through the sleeves into the most distal nail hole. The guide sleeve closest to the top of the attachment guide contains a trocar, which is used to create a path through soft tissues and to score the bone, so that the drill bit purchases the bone at the appropriate site (A). Interlocking screw and bolt (B). Screw-cone peg (C). **Angle-stable interlocking nail with screw-cone pegs** (D–E)

Answer 39

Should not exceed **70-90% of isthmus** 3.5-4.7mm nails for cats/sm. dogs 6mm 15-30Kg 8-10mm for large or giant breeds

Answer 40

Blunt tips Normograde placement - entry hole, extension piece to nail Controlled impacted with mallet (more secure than twisting) Etch marks assess depth 2 Locking devices in prox and distal = 1-2 bone diameters from fracture and in metaphyseal region Locking device not sucessfully placed through distal hole in 28%

Answer 41

Normograde: lateral junct. crest of greater tubercle and the greater tubercle Seated proximal to supratrochlear foramen (or retrograde) Prox locking device should be distal to level of greater tubercle

Answer 42

83-96% success, 95% heal w good function by 3m (median 6w vs 8w) Complication = 4-23% - Pulmonary embolism (2 dogs) - bending/breaking drill bit, nail, screw or bolt - fracture of bone through hole, fx prox or distal to nail - osteomylitis - nerve damage (radial or sciatic) \_ quads contracture, psuedoartho]\rosis, granuloma at tip, windshield wiper effect, pain, infection, seroma, instbility, delayed/non-union

Answer 43

if fx line is \<1.5x the diameter of the bone

Answer 44

Pull out strength determined by outer diameter and strength of material it is placed in Bending strength = core diameter

Answer 45

316L stainless steel steel (reconstruction plates may be softer) Titanium plates: theoretical advantage with respect to failure, not as stiff or strong as stainless steel

Answer 46

* Even stress distribution - AMI less between screws, can bend over the whole plate * Periosteal damage less * Holes allow screw angulation more (80 degress longituindally, 14 degrees side to side * Bidirectional compression * Strength compared to DCP – similar, maybe sl. weaker, no significant difference

Answer 47

Softer steel Weaker than DCP V notched = contour in 3 directions Sizes: 2.0,2.7,3.5 (no 4.5)

Answer 48

Importance of the plate-span ratio and plate-screw density in bridge plating technique. The schematic drawing shows mechanically sound fixation of a multifragmentary diaphyseal fracture in the lower leg. The ratio between the length of the plate and the length of the fracture is known as the plate-span ratio. In this case, the ratio is high enough, that is, approximately 3, indicating that the plate is three times longer than the overall fracture area. The plate-screw density is shown for all three bone segments. The proximal main fragment has a plate-screw density of 0.5 (three out of six holes occupied); the segment over the fracture has a density of 0 (none of the four holes occupied); and the distal main fragment has a density of 0.75 (three out of four holes occupied). The higher plate-screw density in the distal main fragment has to be accepted, because for anatomic reasons, there is no way of reducing it. The overall plate-screw density for the construct in this example is 0.43 (six screws in a 14-hole plate).

Answer 49

Poor bone quality Comminuted metaphyseal or diaphyseal fx Periprothetic fx Complex periarticular fx

Answer 50

LCP (synthes, locking compression plate) String of pearls (standard cortical screw) Advanced locking plate system (ALPS, Kyon) Fixin (traumavet Italy)

Answer 51

extensive soft tissue dissection, disruption of the fracture hematoma, multifocal periosteal necrosis secondary to plate compression, and iatrogenic trauma associated with interfragmentary implants such as lag screws and cerclage wires. In this study (human), the best predictor of success was the use of longer bridging plates with fewer plate and interfragmentary screws. Biological osteosynthesis, time to union decreased from 20 to 13 weeks, nonunion rates decreased from ≈10% to ≈4%, and revision surgery rates decreased from 43% to 13%. Overall, the success rate increased from 62% to 87%, despite a drastic decrease in the use of bone grafts, from 30% to 4%.

Answer 52

Immature animals \<5-6m Due to weak bone, failure of bone-screw interface with pullout complication of stiffer implants long thin plate that span entire bone with few screws, increased working distance Clinical union 2w, union by 4w in all cases Immediate and 4-week postoperative radiographs of a comminuted diaphyseal fracture treated using a locking compression bone plate applied in bridging mode. Note that in the absence of anatomic reconstruction, no load sharing occurs between the bone and the plate, which now sustains all forces at the fracture gap. The plate is secured onto the bone using two to three screws at each end. This results in increased compliance of the construct and decreases the risk of fatigue failure. Indirect reduction and percutaneous plate fixation were performed to preserve the fracture site and optimize bone healing potential. These principles serve as the basis of biological osteosynthesis and are applied to promote early formation of callus and rapid clinical union as observed by 4 weeks postoperatively in this case

Answer 53

Recommend 35-45% For each 10% increase, strain reduced by 20% Overal stiffness increased 6% for 30%, 40% for 40% and 78% for 50% (too ridgid)

Answer 54

anatomic location (metaphysis, trans-cortical defects for bridging) relative compliance (increased bridging?) limited reliance on plate screws near the fx site elimination of interfragmentary implants limited use of bone grafts MIPO l**onger plates (high plate bridigng ratio), fewer screws (low plate screw density), low plate span ratio (plate to fracture length ratio)**

Answer 55

Steel plate = 4.5x increase axial stiffnes and med/lat bending, 2x increased cr/cd bending and stiffness Double steel connecting bar = 80% stiffer in axial and 170% stiffer in med/lat beneing compared to external plate. = stiffness of IIb or 50% IIa

Answer 56

larger diameter bar to increase stiffness negated when 2 or more full pins used

Answer 57

stonger frame hybrid design Tie-ins threaded pins

Answer 58

\>4 per segment

Answer 59

no greater than 20-30% bone diameter = stress riser Evenly spaced, no closer than 3x pin diameter or 1/2 bone diameter from joint/fracture

Answer 60

reduce pin-bone interface stress smooth pins at 70 degrees to long axis position bar closer to the bone = stiffer construct Pin stiffness porportinal to the pin length^3 (shorter is stiffer) No chuck (wobbles), power drill \<150rpm 60 degree pin offset = 4-5x stiffness in 1a (acylics)

Answer 61

1- increased stiffness in bending/shear and decreased stiffness in axial compression 2. small fragmenrs 1-1.5cm 3. adjustable after placement

Answer 62

1. Aseptic technique 2. Proper locaiton for pin insertion 3. Select most suitable ESF 4. Auxillary fixation when indicated 5. Maintain stabilization and reduction when applying frame 6. Insert pins without damaging soft tissues 7. proper pin insertion technique 8. Engage both corticies 9. insert smooth pins and neg. profile pins at 70 degree angle 10. Insert all pins in same plane when using bar 11. Even distribution - optimize mechanical stability 12. 3-4 pins in each fragment 13. Optimal size implants 14. Optimal distance between clamps and skin 15. Cancellous graft in sig cortical defects

Answer 63

Decreased surgery time 45% Decreased healing time 27%

Answer 64

Robinson sling Other wierd slings = schroeder thomas

Answer 65

Reduction = at least 50% contact of cotical fracture fragments Proper alignment Neural standing angle immobilize joints above and below

Answer 66

Grade 1 = overstretch ligament Grade 2 = partial tear Grade 3 = complete tear

Answer 67

Non-ridgid, semi-ridgid, Rigid Static vs. Dynamic Stifle braces: prophylactic, rehabilitative, funcitonal Contracture/assist type braces

Answer 68

Viable = mechanical issue (motion, fracture gap), biologically OK - Hypertrophic - Moderately hypertrophic - Oligotrophic - some biologic failure as well (loose implant at fracture- prevent bone proliferation and vascularization. Non-viable = biologically inactive - Dystrophic - compromised vasculature/non-viable bone 1 or both sides - Necrotic - infected dead bone = sequestrum - Defect - gap too large and filled with non-bone (fibrous or muscle) - Atrophic- result of above types, host removes bone but doesn't replace

Answer 69

Extracorporeal shock wave - hypertrophic but not atrophic Pulse electromagnetic field Low intensity pulsed US

Answer 70

mechanical lateral distal humeral angle = 83.7 +/- 2.9 degress

Answer 71

1) No appearance of medial or lateral surfaces of the anconeal process 2) The distance from the medial epicondyle to the med cortex olecranon is 45% of the transcondylar distance

Answer 72

aMPRA = 83 aLDRA= 86 aCdPRA = 85 aCdDRA = 22 Procurvatum = 27

Answer 73

procurvatum = (90-aCdPRA) + (90-aCdDRA) + theta

Answer 74

proximal radial joint orientation line (frontal plane) = proximolateral edge of the radial head and the medial portion of the coronoid process OR distal aspect of the humeral condyle distal radial joint orientation line = lateral-most aspect of the articular surface and the medial aspect of the articular face, ignoring the styloid process. anatomic axis is drawn by connecting three points with a best-fit line that bisects the radius at levels within the metaphyses and mid-diaphysis. (aMPRA) and (aLDRA)

Answer 75

distal joint orientation line = distal-most aspect of the lateral and medial femoral condyles proximal joint orientation line = center of the femoral head to the dorsal-most aspect of the greater trochanter of the femur. anatomic axis = line that connects points selected 33% and 50% below the proximal aspect of the femoral neck in the middle of the femur (_normal distal femoral varus_) (aLDFA), (aLPFA) mechanical axis = line that runs from the center of the femoral head to the center of the distal femoral joint orientation line. (mLDFA), (mLPFA) i

Answer 76

Femoral angle of inclincation = angle formed by the proximal anatomic axis and a line that bisects the femoral head/neck coxa vera = decreased AOI coxa valga = increased AOI Normal angle of inclination = 134

Answer 77

anteversion angle of femoral head and neck = angle between the neck and frontal plane of the caudal aspect of the condyles Normal = 27-31 In 4 studies, axial range = 16-30.8, oblique planer analysis = 31.3, CT 19.6

Answer 78

Labs, Golden, GSD, Rotties aLDFA = **97,** 97, 94, 98 aLPFA = **103**, 98, 101, 96 mLDFA = **100**, 100, 97, 100 MLPFA = **100,** 95, 97, 93

Answer 79

the frontal plane, prox orientation line = distal points of the subchondral bone concavities of the medial and lateral tibial condyles distal point angle = most proximal points of the subchondral bone of the two arciform grooves of the cochlear tibiae mechanical axis = point in the center of the proximal-most aspect of the intercondylar fossa of the femur and at the most distal point of the subchondral bone of the distal intermediate tibial ridge (mMPTA, mMDTA) Saggital proximal tibial joint orientation line = cr. and cd. aspects medial tibial condyle Distal tibial joint orientation line = distal aspect of the distal intermediate ridge of the tibia cranially, and the caudodistal aspect of the cochlea tibia caudally. mechanical axis = midpoint between the apices of the two tibial intercondylar eminences and the center of the circle created by the talus. (mCdPTA, and mCrDTA)

Answer 80

mMPTA = 93 mMDTA = 96 mCdPTA=64 mCrDTA = 82

Answer 81

Torsion \> 15 degrees = \>5 degree miscalculation in frontal deformation Each CORA had a location, plane and magnitude

Answer 82

CORA on convex = opening CORA on concave = closing A distal antebrachial deformity with resulting intersection of anatomic axes (red). Bisection of the mediolateral angles formed by the intersecting axes results in determination of the transverse bisecting line (tBL), which is an infinite line of centers of rotation of angulation (CORAs); the CORAs are named opening (light blue) if on the convex side of the neutral CORA, and closing (dark blue) if on the concave side. Basing the angulation correction axis on an opening or a closing CORA results in an opening or closing wedge ostectomy, respectively

Answer 83

Canine antebrachium with distal uniapical deformity as determined by the intersection of proximal and distal anatomic axes (red) as determined from joint orientation lines (green). The magnitude of the center of rotation of angulation (CORA) is calculated as the angular difference between the axes (α). The location of the CORA is measured from a nearby anatomic landmark, such as the radiocarpal joint. If angulation is apparent in both orthogonal planes, then an oblique plane deformity is present. It is necessary to determine the plane of the deformity. This can be done by using a graphical interpretation of oblique plane analysis, as discussed in the next section.

Answer 84

of CORAs = Uniapical, biapical multiapical If biapical = partially compensate (valgus and varas) or **non**compensated (2 of the same) Translation deformitiy Oblique plane deformities hondrodystrophic dog might be classified as having a biapical, partially compensated radial deformity with a proximal varus and distal valgus and concurrent procurvatum and external torsion. Similarly, a giant-breed dog with a grade IV medial patellar luxation may have a uniapical distal femoral varus deformity with external torsion.

Answer 85

Paley's rules of osteotomies. A, Rule 1: If the osteotomy (black line) and the angulation correction axis (ACA) (yellow circle) pass through any of the centers of rotation of angulation (CORAs) along the transverse bisecting line (tBL) (dotted line), then the bone is appropriately realigned through angulation. B, Rule 2: If the osteotomy is completed at a level different from the CORA, but the ACA is based on a CORA, appropriate realignment of the bone occurs through angulation and translation. C, Rule 3: If the osteotomy and the ACA occur at a level different from the CORA, then co-linearity of the segments does not occur, and iatrogenic translation results.

Answer 86

Advt = maintatins bone length, only 1 cut, maintains apposition, resists shearing loads Dis = can only be performed on uniplaner deformities

Answer 87

advantages of a dome osteotomy include all of those associated with cylindrical osteotomies along with the **versatility to correct deformities in three planes**. Thus, torsion angulation deformities can potentially be corrected with the completion of a single cut. L**imitations arise, however, with application to bones that are nonuniform in cross-section,** such as the canine radius, which is ovoid and thus possesses diameters that differ in the orthogonal planes. This occurs because the dome osteotomy blade must be size-matched with the bone in the widest dimension (in the case of the radius in the frontal plane), which results in size-mismatching in the sagittal plane and large **decreases in postcorrectional apposition and correctional accuracy**.10 Still, the potential usefulness of the saw blade in correcting oblique plane torsional angulation deformities in bones with circular cross-sections, such as the canine femur, is intriguing.

Answer 88

Area of bone surrounding ischemic bone that has increased osteoclastic activity

Answer 89

Metaphyseal region imcomplete basement membraneof capillaries in the region downregulation fo Tcell immunity and cytokines

Answer 90

Staph 60%, mostly intermedius

Answer 91

1. reverisble attachement 2. irreversible attachment 3. growth and differentiaton 4. Disseminaiton

Answer 92

Microbe microbe induced glycocalyx host-bacteria surface

Answer 93

1. Molecular filter 2. Slow growth/reproduction of bacteria 3. Changing the microenviroment - loweing pH, increasing PCO2, decreasing P)2, and hydration levels neg. affect antimicrobials

Answer 94

BMP 2,4,7 TFG beta Insulin GF/GH platelet dervied GF fibroblast GF

Answer 95

Osteogensis - supply and support bone forming cells: autogenous cancellous bone graft, bone marrow Osteoconduction - scaffhold **Osteoinduction** - induces bone formation where no bone would form: chemoattraction/migration, induce proliferation of stem cells - **demineralized bone matrix:** decalcifcaiton without inactivation cytokines (BMP, TNF, etc.) and organic matrix **Osteopromotion - enhances regenerating bone - platelet rich plasma**

Answer 96

Osteoblasts (osteogensis) cytokines/GF (osteoinduction) scaffold (osteoconductoin) blood clot - IGF, PDGF, TGFbeta **(osteopromotion**)

Answer 97

Proximal humerus - large amount Wing of illium - no prob if fx Proxmed tibia **Subtrochanteric portion femur** **Fermoral condyles** Cdventral **Mandibule/rib**

Answer 98

125-1180 microns

Answer 99

20-35% calcium reduced to 3% - favorably influences bone healing Osetoinductive - acid resistnet BMPs and other GFs Can be mixed with other sustances including bone chips (=osteoconduction) Time to destablization of arthrodesis was same for dogs treated with DBM, autograft or both

Answer 100

periosteum bone marrow fat Difference in cell behavior depening on source

Answer 101

1) **Culture epanded autogenous** - isolated from BM by density gradient centrifugation 2) **Culture expanded allgenic** - potentially can cause T-cell mediated cell rejection, but not seen in the clinical setting and healing similar to autogenous MSC 3) **Selective MSC retention** - large bone marrow aspirate passed over demineralized cortical fibers and mineralized cancellous bone chips as an allomatrix - femoral defect - 33% allomatrix alone, 50% BM, 100% selective retention

Answer 102

chemistry/sintering = different avilable levels of stiffness, hardness and brittleness Interconnective porosity = allows vasular ingrowth = if low O2, cells become fibroblastic, chondroblastic or adiopoblastic pores 300-500 microns

Answer 103

Ceramics Calcium phosphate ceramics - hydroxapatite, others Coralline bone graft - Ca carbonate→Ca hydroxapatite, 200-500 microns Tricalcium phosphate - Ca:Phos 1:5, hydroapatite 1.67:1= more soluable, granules do not provide support Biphasic calcium phosphate = combo of Tricalcium and hydroxyapatite Nanocrystalline calcium phosphate - hardens with endothermic rx calcium sulfate aka plaster of paris - rapid absorption, not suitable for sturctural support

Answer 104

MSCs → osteoprogenitor = BMP 2,6,9 osteoprogentior to osteoblastic = BMP 2,4,7,9 Only 2 and 7 commerically available

Answer 105

Classified as I (fx body/spine/acromion), II neck, III glenod fx OR Stable extra-articular, unstable extra-articular, intra-articular (sx rec for last 2)

Answer 106

Recommend inverted tubular plates as "best fit" Recommend plating dorsal fractures caudally and ventral fractures cranially - do to thickness of bone Locking plates may be benefical but not evaluated Screw angles at 45 degress to spine double vs single plate = double stronger but not stiffer, equally properties with cyclic loading

Answer 107

Photograph of positioning a patient for a distoproximal (axial) radiographic view of the scapula. The spine of the scapula is perpendicular to the table. B, Radiographic image made from the positioning in A

Answer 108

60% = excellent outcome total - fair outcome in 1 case

Answer 109

Distal neck displaces medially Atrophy of the supra and infraspinatus

Answer 110

Cross pin fixation (visualize supraglenoid tubercle and caudal aspect of glenoid Divergent pin fixation (through supraglenoid) Plate (T or L plate) Place in Velpeau post op

Answer 111

osteotomy of the greater tubercle of the humerus tenotomy of the infraspinatus and/or teres minor muscles. A recent study described a muscle separation approach to the scapular neck, which avoids the need for acromial osteotomy. After dissection through the deep brachial fascia and cranial retraction of the omotransversarius muscle, the fascial plane between the supraspinatus muscle, the acromial head of the deltoideus muscle, and the infraspinatus muscle is dissected. The supraspinatus muscle is retracted cranially, while the infraspinatus muscle and the acromial head of the deltoideus muscle are retracted caudally

Answer 112

28% are articular 58% cranial glenoid 23% T or Y fx

Answer 113

Tubercle = accessory center of ossifcation, fuses at 5m Osteotomy of greater tubercle or myotomy of supraspinatus m. Lag screw +k wire OR tension band OR excise fragment If excision = tenodesis of biceps brachii

Answer 114

Approach in which a longitudinal myotomy of the supraspinatus muscle precludes the need for an osteotomy. The myotomy begins at the level of the midbelly of the supraspinatus muscle and continues distally to the level of its humeral insertion.

Answer 115

approach may include **osteotomies of the greater tubercle or acromion, as well as tenotomy of the tendon of insertion of the infraspinatus or teres minor muscles**, or any combination of osteotomy and tenotomy. With T or Y fractures, the articular surface should be reduced anatomically first, using a screw in lag fashion (Figure 50-9). The screw is typically directed in a craniocaudal direction. The neck is then reduced and stabilized to the scapular body as described earlier. Fractures of the medial or lateral labrum of the glenoid are less common, and in small breeds, inadequate bone may be available for adequate implant purchase (Figure 50-10). In larger dogs, if adequate bone is available, one or two lateral-to-medial directed screws may be placed in lag fashion

Answer 116

Excision of the glenoid OR scapulohumeral arthrodesis

Answer 117

Ununited accessory ossificaiton center of the caudal glenoid Often bilateral Treat with arthroscopic removal if causing pain

Answer 118

Scapular luxation is typically stabilized using 20 or 22 gauge cerclage wire that is passed around the fifth, sixth, or seventh rib and through holes drilled near the caudodorsal border of the scapula in the area of the origin of the teres major muscle.13 Additionally, the insertion of the serratus ventralis muscle on the scapula may be reconstructed through drill holes at the craniodorsal angle of the scapula

Answer 119

2/3 glenohumeral joint 1/3 scapulothoracic synarcosis

Answer 120

glenohumeral = 6m proximal humeral = 1yr

Answer 121

Medially = subscapuaris, coracobrachialis Laterally = supraspinatous, infraspinatous and teres minor

Answer 122

dogs 57-165 degrees cats 32-164 degrees

Answer 123

Passive = limited joint volume, adhesion/cohesion mechanism, concavity compression, capsuloligamentous restraints Active: supraspinatous, infraspination, teres minor, subscapularis, biceps brachii, long head triceps, deltodieous and teres major

Answer 124

The glenoid provides relatively little coverage of the humeral head, and the joint, based on topographic distribution of cartilage thickness, is classified as being moderately congruent. The **cartilaginous glenoid lip (labrum glenoidale or labrum**) surrounds the glenoid on all sides, is **wider on the lateral side, and extends the surface area of the glenoid by 25% to 30%**. The labrum is triangular in cross-section and is highly vascularized, except along the free margin.75 Both articular surfaces are covered in hyaline cartilage of moderate thickness (approximately 1 millimeter thick in 20 to 25 kg dogs), as is typical of moderately congruent joints

Answer 125

Type 1, 2, and 3 mechanoreceptors present in the collateral ligaments of the shoulder allow the ligaments to serve not only as passive restraints but as sensory structures that actively contribute to joint stability.51 Type 1 (Ruffini) receptors are most common and are more densely concentrated at the cranial aspect of the scapular side of the ligament

Answer 126

Caudal central or caudal medial aspect of humeral head 27-68% bilateral Usually large breed dogs

Answer 127

nonmineralized cartilage flaps trapped within the biceps tendon shealth - why US or MR or contrast may be useful

Answer 128

craniolateral (Hohn) Caudal (Gahring) The caudal approach requires a surgical assistant to provide tissue retraction for adequate viewing of the osteochondritis dissecans flap but results in less loss of shoulder range of motion and increased weight bearing (as evidenced by increased peak vertical forces when compared with the lateral approach), at least within the first month after surgery. The lateral approach offers increased exposure of the caudal humeral head.

Answer 129

Glenoid dysplasia with med luxation Treat with excision arthroplasty (glenoid +/- humeral head) or arthrodesis

Answer 130

A lateral approach111 to the shoulder is recommended, and the glenoid is excised by making a distolateral-to-proximomedial osteotomy of the scapular neck with an osteotome or, preferably, a sagittal saw (Figure 51-4). The suprascapular nerve should be identified and protected while the osteotomy is performed No evidence to support humeral head excision

Answer 131

In small dogs, arthrodesis can be performed by placing a **large transarticular screw or diverging Kirschner wires** (with or without tension band wire); this method is not recommended in medium- or large-breed dogs, and clinical outcomes are generally better when plates and screws are used for all sizes of dogs and cats. Arthrodesis of the shoulder using bone plate and screws is performed through a **craniolateral approach.** The insertion of the **trapezius** muscle and the origin of the **omotransversarius** muscle are elevated from the cranial edge of the scapular spine as needed. The incision is continued distally along the cranial border of the acromial head of the deltoideus muscle. If greater exposure is required, an **osteotomy of the acromion** can be performed and the acromial head of the deltoideus muscle retracted caudally. The **omobrachial vein** (and cephalic vein, if necessary) is divided and the incision follows the **lateral aspect of the brachiocephalicus** muscle to its insertion. The insertion of the **superficial pectoral** muscle is incised and the muscle elevated and retracted cranially. An **osteotomy of the greater tubercle** allows elevation and retraction of the supraspinatus, or, alternatively, the insertion of the supraspinatus muscle on the greater tubercle is incised and elevated as needed to allow placement of a bone plate and screws along the cranial aspect of the humerus. The elevation of the **supraspinatus muscle** is continued proximally through the entire supraspinous fossa until the muscle can be retracted cranially. The suprascapular nerve should be identified, carefully retracted, and protected at all times. If necessary, the insertional tendon of the infraspinatus muscle is transected and the muscle retracted caudally. This approach exposes the entire **craniolateral aspect of the scapula and the cranial aspect of the humerus**. The lateral collateral ligament is transected and the joint capsule incised to allow luxation of the humeral head from the glenoid fossa. A motorized burr is used to remove the articular cartilage from the surfaces of the humeral head and the glenoid fossa.

Answer 132

Mediolateral radiograph of the shoulder of a dog affected by multiple epiphyseal dysplasia. Observe the severely misshapen and irregular humeral head Radiographically evident by 8w, usually severe lameness by 5-8 months euthanasia bone changes similar to **congential hypothyroidism**

Answer 133

105-110 degrees

Answer 134

Disease in plateu humeral head greyhounds and femoral head GSD White spots on cartilage = hydrosyapatite (pseudogout) Incidental finding??

Answer 135

Biceps tendon test Drawer test Biceps retraction test

Answer 136

Radiographs = **flexed crainodistal-cranioproximal skyline** veiw, allows surpraspinatus vs. biceps Contrast arthrography - may be more sensitve than US US: Sonolucent line around the tendon; an enlarged, hypoechoic tendon with fiber pattern disruption; irregular or proliferative synovium; and, in chronic cases, irregularities in the surface of the bicipital groove - not all cases have US changes MRI: in one study all biceps tendopathy had concurrent joint problems Arthroscopy

Answer 137

Skyline radiographic view of the cranial aspect of a dog shoulder demonstrating a small mineralization within the tendon of the supraspinatus muscle (arrow). The tendon of origin of the biceps brachii muscle lies medial to the greater tubercle, within the intertubercular groove.

Answer 138

1-2 injections of methylpred (10-40mg) or trimacinolone (5mg) intra-articluar with 4-6 weeks cage rest Tenodesis - open or arthroscopy, attach to prox. humerus Tenotomy - open or arthroscopy Drawing of a biceps tenodesis performed with the use of a cannulated screw and washer. B, Mediolateral radiograph of a biceps tenodesis performed with the use of a cannulated screw and washer in a dog

Answer 139

**medial displacement with rupture transverse humeral ligamen**t: Varying degrees of atrophy of the deltoideus, infraspinatus, and supraspinatus muscles, pain with range of motion, and a “popping” sound with range of motion. variable duration and severity of lameness. Varying degrees of atrophy of the deltoideus, infraspinatus, and supraspinatus muscles, pain with range of motion, and a “popping” sound with range of motion have been reported rupture of the tendon rupture of the tendon sheath dystrophic mineralization

Answer 140

with or without calcification Rotties, labs Supraspinatus contraction: trauma or VonWillenbrand or end-stage supraspinatus tendinopathy Pain\>biceps tendopathy Tx: rest and NSAID, extracorporeal shock therapy Sx excision of calcified tissue within tendon/muscle

Answer 141

The enlarged tendon of the supraspinatus muscle may also impinge on the adjacent tendon of the biceps brachii muscle, and excision of diseased tissue may decompress the tendon of origin of the biceps brachii muscle.47 Impingement on the tendon of origin of the biceps brachii muscle may be positional and may be best evaluated when the joint is extended

Answer 142

1. **loss of concavity compression** - abnormally small or flat glenoid, torn or avulsed glenohumeral ligaments, fracture of the lesser tubercle, or a decrease in the depth of the concavity as a result of injury or chronic repetitive wear 2. **disruption of glenohumeral balance** (uncentered net joint reaction force)- dynamic muscle imbalance, abnormal angulation of the glenoid as it interdigitates with the humeral head, and disruption of the capsuloligamentous restraints

Answer 143

Most commonly middle aged, large breed aiwth chronci lameness Positive biceps and shoulder drawer **Abduction angle (normal 30, abnormal 50**) - measured btwn scapula spine and humerus, must stabilize scapular spine Rads (varus and valgus stressed) - DJD in absence of OCD strongly inficative of instability MRI Arthroscopy - cartilage erosion **caudal region of head** aand **medial ridge of glenoid** US NOT useful for medial

Answer 144

Transposition of the biceps tendon or supraspinatus - both result in abnormal biomech and OA Augmentation of the exsisting medial collateral - anchor large monofilament suture at the origins and insertions of the cranial and caudal bands of the medial glenohumeral ligament in a V-shaped manner inbrication of tendon of the subscapularis - craniomedial approach and was imbricated with two to five horizontal mattress sutures of polydioxanone suture (PDS) Radiofrequency induced thermal modificaiton (RITM) - Only arthroscopic tx- thermal energy is applied to the joint capsule, shrinking the collagen bundles Excision arthroplasty or arthrodesis

Answer 145

woven poly-L-lactide device

Answer 146

modified Campbell prosthetic suture (heavy suture passed through transverse holes in the humeral head and scapular neck to create or augment glenohumeral ligaments

Answer 147

Biceps , Tendon, pectorals, serrutus ventralis, rhomboideus, ex.carpi radialis, flexor carpi ulnaris In human beings, muscles at risk of strain include those that cross two or more joints (subject to stretch at more than one joint), those that have the ability to limit range of motion across a joint by their intrinsic tightness, those that function in an eccentric manner, and those that have a relatively high percentage of type 2 (fast-twitch) muscle fibers

Answer 148

Mediolateral positive-contrast arthrogram demonstrating numerous intra-articular radiolucent filling defects associated with synovial chondrometaplasia

Answer 149

Infraspinatus/supraspinatus mm. contracture Villonodular synovitis Synovial chondrometaplasia Infraspinatus burasl ossification Mineralization = Ectopic or heterotopic ossification of soft tissues (metastaic calicificaiton, dysrophic), Fibroplasia ossificans progressive like syndrome, soft tissue meralizaiton (progressive, multifocal nonprogressive disorder - excision of mineralization may make worse)

Answer 150

In the cat: Supracondylar foramen – proximal to the medial epicondyle ¤Supratrochelar foramen absent ¤Closed with bone, while dogs have membrane ¨Median n. and branch of the brachial a. pass through the supracondylar foramen

Answer 151

Physeal fracture of the proximal humerus with the greater tubercle and humeral head fragments remaining together. B, Repair with two Kirschner wires and a tension band wire. C, Repair with two Kirschner wires. D, Repair with a lag screw

Answer 152

Pin with plate 35-50% diameter of diaphysis Pin can be directed in 4 ways (all directed): proximal retrograde, distal retrograde, proximal normograde (cr-lat greater tubercle to trochela) or distal normograde 20% of pins placed in a non-directed proximal retrograde penetrated shoulder joint

Answer 153

Not ideal for humerus - Tapering shape - Distal fractures, only room for 1 locking device - Poor screw holding power in proximal humerus ¨Described (20, 21, 61) for Mid-diaphyseal fractures - 2 locking devices, 1 bone diameter from the fracture - - If 1 locking device proximally, place distal to tricipital line - - Young dogs - - Too larger to place through medial epicondylar cres

Answer 154

Convex crainolateral surface = proximal tension aka place plates **cranial and lat** for proximal fractures Caudomedial surface - distal tension aka place plates **medially** for distal fx Plates not usually placed caudally except in medial epicondyle region where plates can be placed caudallyor medially/both

Answer 155

Intramedullary pins – 2 pins places in crossed or rush fashion •Better for rapidly healing hones and simple fractures Best results when medial and lateral plates applied * Caudomedial placement allows for greatest purchase, while avoiding the olecranon * Medial placement used if extending proximally * Can place 2 medial plate (caudal and cranial medial) if small distal fragment Monocortical screws and locking plates – decreased risk screw placed in the joint ESF as described for diaphyseal fractures

Answer 156

Prox = type 1 or 2 Distal = type 4, type 1 rare

Answer 157

The lat and med epicondyles stronger and wider olecranon fossa absent

Answer 158

41% of the humeral fracture 34-67% lateral aspect 6. 9-11% medial aspect 25. 9-35% intracondylar (T-Y fractures)

Answer 159

Only 20% of humeral growth from distal - normal closure at 5-8m (fracture usually at 4m) mild insig. humeral overgrowth no decrease in length even when plates cross the physis

Answer 160

¨Increase surgery time associated with increased risk complications ¤Every 30 minutes odds complications increased by 2 ¨Fracture gap associated with increased risk fracture failure ¤Increased shear on screw, larger bone hole = screw loosening ¨Transcondylar screw angle ¨IOHC **Lack of corrleation between reduction and outcome**

Answer 161

132 fractures * 61 stabilized with a transcondylar screw and supracondylar K wire * 13 transcondylar screw and supracondylar screw * 61 transcondylar screw and plate Complications more common with K-wire (28%) than plate or screw (11%) Cases with complications more likely to have a poor outcome Overall 41% had complications, 18% of cases had major complications and required a second surgery • Complications: Implant loosening (14), implant failure (14), infection (19), seroma (6), malunion (1), diaphyseal fracture (1), lysis around implants (2)

Answer 162

AKA: **Intercondyler, dicondylar, bicondylar fracture** ¨Approach: Osteotomy of the tuber olecrani - - Complications with repair osteotomy in 37% cases Tenotomy of the biceps brachii Separate lateral and medial approaches

Answer 163

With osteotomy or tenotomy: Transcondylar screw Condyle attached to diaphysis via: Bone plate, Lag screws, Steinman pins, K-wires Bilateral Approach: order determined by fracture * Repair the medial aspect (bone plate) * Reposition and stabilize lateral portion of the condyle with lag screw and plate * Accuracy assessed indirectly * **Inaccurate repair of the medial condyle (usually varus) key reason for poor fracture reduction**

Answer 164

**Spaniels** (aka cocker and springer) most common Others: Labs, pointer, GSD, Rotties, Yorkies, German Wachtels, Tibetan Mastiff

Answer 165

15 degree oblique CrMed to CdLat

Answer 166

Conservatie = high rate fx, 43% with partial radiolucent and 8% with complete radiolucent Prophylatic repair = standard later condylar fx +transcondylar bone tunnels, concellous bone graft, recommend lat plate. If fracture more guarded px than trauamtic fx = **23% nonunion**

Answer 167

130 degrees ROM Flexion 36 Extension 165 Supination 17-50 Pronation 31-70

Answer 168

Anconeal process - pronation Supination = LCL (primary), anconeal process (secondary), MCL (third) MCL weaker than LCL, both split into cr an cd crura distal Joint capsule Annular lig

Answer 169

Flex carpus and elbow to 90 degrees = rotate antebrachium to test stability Pronation: dog normal 30, transect MCL (60-100); cat normal 50, no MCL (99) Supination: dog normal 46, transect LCL (70-140), cat normal 130, no LCL (167)

Answer 170

antebrachium abducted and externally rotated lateral epicondyle less distinct Rads

Answer 171

Reconstuction of lig. +/-augmentation (locking loop) Ligament replacement with syntehtic materials = transverse bone tunnels or screws/washers or lag screw through avulsed piece If bilateral lig rupture: Transcondylar tunnel and biaxial suture repair After treating need joint immobilzation

Answer 172

Pros: decreased adhesions btwn periarticular structures, Stim GAGs and HA, Stim more orderly collegen deposition/normal cross-linkage, improved joint nutrition and clearence of hematoma Cons: decreased synovial fluid production, decreased cartilage stiffness and thickness, DJD, loss of muscle mass and bone/mineral content

Answer 173

2 centrally threaded pins through dital humerus and olecranon allow 140 degree extension removed 3-4 weeks post-op Flexible external skeletal fixation after reduction of a traumatic luxation. A, The pins are connected with connecting bars immediately after surgery. B, Once swelling is reduced, the connecting bars are replaced by tight rubber bands, to allow limited flexion of the elbow joint Px: 47-89% good with closed reduction, 37% residual instability

Answer 174

I: Lat of cd-lat dislocation of the radial head with ulna in normal position, med-large breed, mild deformity, loss of function II: Disruption humeroulnar articulation with lat rotation and subluxaiton or luxaiton of the ulna, sometimes with dislocation of radial head - most common, small breed, severe disability III: Luxation of radius and ulna - no breed, general laxity (polyarthrodysplasia), multiple congenital skeletal deformites

Answer 175

Convex articular fovea or radial head hypoplasia prox radial diaphysis/epiphysis Lateral andular deformity of the proximal radial diaphysis Angular deformity of the distal humerus (trochela further distal) Medial deviation and distorion of olecranon Cr. curvature prox ulna Secondary OA

Answer 176

Open reduction/stabilization - lateral approach to prox radius, oblique osteotomy/ostectomy distal to radial physis, Radial head ostectomy: poor outcome modified Bell-Tawse procedure: (1) dissection of the soft tissues surrounding the radial head and humeral condyle through a lateral approach radial, (2) wedge ostectomy and counterclockwise rotation of the proximal radius, followed by plate fixation to align load transmission along the axis of the radius, (3) reconstruction of the annular ligament with a muscular fascial strip obtained from the extensor carpi ulnaris muscle (modified Bell-Tawse procedure), and (4) temporary (20 days) humeroradial fixation with a transarticular Kirschner wire. Arthrodesis: no pain but marked gait abnormality Total elbow contralidicated

Answer 177

If \<4m closed reduction and transarticular pin or modiefied ESF If\>4-5m open reduction, then: **medial imbrication,** **transposition of the olecranon medially and distally,** **ulnar osteotomy and radioulnar synostosis,** **trochlea and trochlear notch reconstruction,** external fixation, and transarticular pins. If the trochlea and trochlear notch are fairly congruent, lateral release, medial imbrication, and distomedial olecranon transposition/modified external fixation may be sufficient to maintain reduction

Answer 178

BMD and mastiffs, others GSD Golden, lab, newfie, rottie, St. Bernard 20-35% bilateral Males 2:1 over females FCP in 13%, RU incongrence 50% No separte ossification in sm dogs, large dog between 14-20w

Answer 179

After 22-24 weeks

Answer 180

1. **Excision** (caudolateral approach, midbelly incision) - 90% owner satsified, normal flexion 58%, normal extension 85%, 50% free of lameness 2. **Reattachment AP** (dogs \<24w with normal notch, lag screw or K-wires) - 3. **Ulnar osteotomy +/- reattachement (elbow incongurity)** - 3-6cm distal to radial head, obliquel starting prox cd/lat at 40-50 degrees - or IM pin - variable portion should union of AP 20-70%, improvement 80-90%

Answer 181

Young, large - giant breed dogs (OCD 5-8m, MCD 13m) male 2:1 Smaller chondrodystrophic disease Bilateral 25-80% Incidence of multiple components of ED: 0-60% Several lesions in 42% GSD, incongruity and MCD most common (34%), incongurity diagnosed in 16% (most common singular condition?)

Answer 182

20-22 weeks

Answer 183

1. HU incongurity - insufficient growth ulnar notch 2. RU incongurence and HU conflict - short radius, redistribute forces to MCP, step of 0.5 normal , increased to 1.4mm in MCP - Found in 14% (CT) and 22% (arthroscopy) of dogs with MCP - Absence of staic doesn't mean no dynamic, temorpary or localized (Bardet 1997, Gemmill 2005) 3. Rotational incongurity - transmission of shear forces from the BB/B muscle to MCP = conversion of supinaiton to shear forces along the radial incisure (Therory behind BURP)

Answer 184

MCD type 1: Fragment on the medial margin of the medial coronoid process Type 2: Erosion /fragment of the lateral rim of the MCP Type 3: Free fragment (in situ, nondisplaced or minimally displaced and attached) Type 4: Fissure (cannot be freed by probing alone) Type 5: Multiple fragments Type 6: Osteophyte on MCP Type 7: Joint mouse (displaced fragment, fractured osteophyte)

Answer 185

Flexion and suppination

Answer 186

100% spec, 23% sens, 57% accurate

Answer 187

Subtrochlear sclerosis - 87% Osteophytosis of AP - 70% Osteophytosis lateral condyle - 56% Osteophytosis radial head - 37%

Answer 188

DMPLO 35 degrees

Answer 189

Sens 78%, Spec 86% 1.5-4mm step required for 90% sens \>2mm 94-100% sens

Answer 190

Avoid median n. Flexor carpi radialis and pronator teres separated Can be combined with osteotomy fo medial epicondyl or tenotomy of pronator teres

Answer 191

Post removal of OCD flap - donor cores harvest from non-weight bearing regions of the stifle - core 1mm wider that recipient site and 2-3 mm deeper Benefits: Accurate reconstruction, subchondral and articular contour, resufacing with hyaline cartilage, barrier between subchondral bone and synovial fluid Cons: Regional differences in cartilage thickness, lack of evidence of benefit, donor site morbidiity Suboptimal results in 33 elbows with OCD (MCD in 31), suboptimal results

Answer 192

Biciptial ulnar release procedure for **rotational i**ncongruity medial to joint so flexion = supination and shear along radial incisure Tenotomy distal insert BB/B ( ridge caudal to MCP) Recommended for cartilage malacia or fissures along radial incisiure, poss. adjunct to fragment excision in dogs with no incongurence and mild changes Weak evidence, traumatic rupture in Greyhounds = hyperextension, + biceps test, circumduction

Answer 193

Proximal ulnar ostectomy +/- pin Medial coronoidectomy BURP Radius lengthening not recommended

Answer 194

multimodal medical management sliding humeral osteotomy (shift weight laterally) usually combined with arthroscopic treatment of medial coronoid lesions (medial opening wedge of humerus 10 degres - goal to shift wt laterally - 30% fracture fixation failure) arthrodesis elbow replacement.

Answer 195

1) caudomedial aspect of the radial head 2) the medial aspect of the distal articular surface of the trochlear notch, extending to the radial incisure of the coronoid process 3) the craniolateral surface of the proximal trochlear notch

Answer 196

4mm 25% 8mm 28% Improvement in lameness in 50-100%, 66% of cases Complicaiton rate 19% - major complications more common post medial epicondylar osteotomy (abandoned approach)

Answer 197

Synopsis of past and current linked (A) and unlinked, semi-constrained total elbow replacement (TER) systems (B–E). From left to right: Chancrin, Lewis (third generation), Cook, Iowa State (Conzemius fourth generation), and TATE (Acker/Van Der Muelen). Chancrin's prosthesis (A) was a pure linked, hinged system. The current Lewis prosthesis (B) is a hybrid three-component system in which the humeral component and a radial ultra-high-molecular-weight-polyethylene (UHMWPE) button (allowing pro-supination) are cemented, and a radioulnar (RU) shelf is screwed to the ulna. This system is still in limited use today. Cook's prosthesis (C) used a hybrid cemented/screwed design. This system has been abandoned because of severe complications. The current Iowa State (Conzemius) prosthesis differs slightly from the one depicted here (fully cemented [D]). It now uses a hybrid design, allowing bone ingrowth at the level of the lateral and medial condylar surfaces. Finally, the TATE (Acker) prosthesis was designed as a resurfacing cementless cartridge unit

Answer 198

Composite fixation (cemented and porous) system cobalt chrome humeral stemmed component and a 120 degree arc ultra-high-molecular-weight-polyethylene (UHMWPE) radioulnar component. The articular surfaces of both components are symmetric with respect to the sagittal plane and therefore do not differ between right and left implants. The humeral stem can be used in both left and right elbows, whereas right and left radioulnar components feature side-specific peg locations. The humeral stem and radioulnar posts are cemented in the corresponding medullary cavities for primary implant fixation. The lateral and medial aspects of the humeral stem feature a porous surface for subsequent osteointegration and long-term fixation. The humeral and radioulnar components are implanted individually in sequence

Answer 199

TATE Elbow system uses a cementless resurfacing design consisting of a cobalt chrome humeral component and a 175-degree arc ultra-high-molecular-weight-polyethylene radioulnar component featuring a cobalt chrome metal backing. Both humeral component and radioulnar metal backing feature two mediolateral posts for primary fixation and a porous surface for long-term stability via bone ingrowth. The TATE Elbow system was designed to use a minimally invasive approach via osteotomy of the medial humeral epicondyle. During implantation, both components are linked by a set plate and are inserted simultaneously as a “cartridge implant.”

Answer 200

Interosseus lig annular lig - radius incisures med/lat on ulna oblique lig med/lat collateral lig - cr/cd crura radioulnar lig - joint capsule conflent with interosseois membranes

Answer 201

100% distal ulnar physis - closure at 220-250d (7-8m) 30-50% prox radial physis

Answer 202

Dynamic elongation - transverse osteotomy with pins and elastic material Controled elongation - Stader apparatus - ESF with threaded connecting bar - Circular ESF - increase in upto 50% of length Acute distraction (mature animal) - transverse osteotomy with bone graft - sagittal sliding (stairstep) osteotomy with lag screws

Answer 203

Dynamic - **proximal ulnar ostectomy +/- IM pin** - ostectomy \>ostetomy - do not score radius = synostosis **Distal ulnar oestectomy or removal of physis** - in vitro did not allow adequate movement of ulna, some clinical sucesses reported **sagittal sliding osteotomy of the ulna**

Answer 204

gap \>1.5 bone diameter removal of perosteum fat graft

Answer 205

Hueter-Volkmann law (also known as Delpech's law), which states that physeal growth is slowed by excessive compression and is accelerated by distraction

Answer 206

Radial styloid fx (avulsion injury with medial collateral ligament)

Answer 207

70-85% return to function with bone plate Complications: 54%: skin irriaiton, cold conduction, synostosis, angulation osteopenia, plate failure screw loosening

Answer 208

I: Cr luxation of radial head, Cr-prox angulation of the ulnar fx II: Caudal luxaiton of the radius, Cd angulaiton of the ulnar fx III: lateral luxaiton of radius IV: fx of prox radius and ulnar diaphysis, cr. luxation radial head Picture is a type I

Answer 209

Attachment of lateral collateral lig

Answer 210

radioulnar ligament (articular disc) dorsal radiocarpal ligament short ulnar collatearl ligament short radial collateral ligament short lig.

Answer 211

Short radial collateral lig palmar radiocarpal lig palmar ulnocarpal lig accessorometacarpal lig - accessory carpal to MC IV&V Intercapral ligaments Flexor retinaculum - accessory to radial styloid Palmar fibrocartilage - all proximal and number CB (except accessory) and MC3-5

Answer 212

MC1 proximal epiphysis MC2-5 distal Ossification done by 5-6m

Answer 213

Cats: absence of straight medial collateral lig of the carpus = feline antebrachiocarpal luxation with only partial disruption of MCL Dogs: Lack dorsal elastic lig attachement to the head of the middle phalanx - may allow cats to hold prey

Answer 214

Stance = 18 degrees mos of stance -12.4 at start to 26 degrees at 75% stance 10 degree +/-12 Peak antebrachiocarpal joint angle = 47.3 degrees at 50.9% stance Peak metacarpophalangeal joint angle = 19.2 +/- 6.1 (at 62.6% stance)

Answer 215

58.3% failed by mid lig tear, 22.9% avulson fx, 18.8% bone-lig interface Highest elastic modulus: accessorometacarpal ligs \>palmar radiocrpal and ulnocarpal ligs \> medial and lateral collateral ligs

Answer 216

Boxers, English Springer Spaniels, Setters, Pointers Males predisposed Usually active

Answer 217

**dorsal slab** **midbody saggittal (dorsoproxlat to palmardistmed)** **Comminuted T shaped** May result from incompete fusion of the 3 centers of ossificaiton of the radial carpal bone Traumatic in right carpal of Greyhounds: most common **oblique midbody fx** and **chip/avulsion** at attachement of palmar carpometacarpal lig or oblique part short radial collateral

Answer 218

lag screw: palmaromedial aspect in dorsolat direction K-wire excision of fragments Approaches: dorsal (dorsal slab), palmaromedial (midbody RC fx), combination to increase exposure

Answer 219

5 types: I: (67%) avulsion fx dital margin articular surface at attachemnt of lig from AC to ulnar carpal - Ia: palmarolateral - Ib: palmaromedial II: (13%) prox margin of articular surface AC at the origin of the lig from AC to distal radius III: (3%): avulsion at the distal surface at the caudal end of the AC IV: (12%): Avulsion tendon insertion flexor carpi ulnaris at caudoproximal surface AC V: (3%): comminuted fx

Answer 220

Type V: non-surgical Palmarolateral approach Fragment removal or interal fixation (1.5 or 2mm lag or positional screw) Preserve accessormetacarpal lig and the accessoroulnar carpal lig

Answer 221

\> or = 2 meta fx same limb involve both wt bearing bones articular displaced \>50% base of meta II or V large breed or atheltic dog

Answer 222

MC V left and MC II right

Answer 223

I: endosteal and cortical thickening - rest/NSAID 3m II: minimally displaced hairline - external coaptation 6-8w III: complete fx with dispalcement - surgical Px good I and 2, guarded 3 70% return to training

Answer 224

medial approach MC 2, Lateral MC 5, rest dorsal Avulsion fx meta 2 or 5 = lag screw or pin/tension band Amputation IM k wires (normograde) Dowel pinning bone plates ESF

Answer 225

Sesamoid disease Greyhound, Rotties, Labs, Austrailian Cattle Dogs Usually 2 and 7 (fewer vascular foramina) lameness, pain, joint effusion, reduced flexion Rest for 4-8 weeks Surgery to remove frag or sesmoid (palmar appraoch)

Answer 226

Antebrachiocarpal = 10-31% Middle = 22-50% **Carpometacarpal** = 40 -47% Conservative management usually not sucessful = arthrodesis

Answer 227

27% thoracic limb 69% medial surface

Answer 228

effects antebrachiocarpal joint the other effected joints cause damage to teh accessory lig, palmar fibrocarilage and the palmar ligs. Complete luxation of any carpal bone or joint (subluxation more common)

Answer 229

Medial Dorsal (most common) - Distal 1/3 radius through length of MC3 - extensor carpi radialis m. tendon to MC2 and 3 severed and other extensors retracted laterally

Answer 230

DCP or LC-DCP hybrid DCP Single of double stepped hybrid arthrodesis plate - more normal relationship btwn radius, carpal bones and MC, smaller MC screw, maintain 10-12 degree without bending plate Castless plate - engages both MC3 and MC4 at 8 degree, available 4 lengths, stiffer and greater load to failure than hybrid with or without cross pins

Answer 231

7-50% ESF = 35%

Answer 232

do not exceed 40% bone diameter plates should span \>50% of the metacapal 3 length

Answer 233

9-12 weeks intercarpal and carpometacarpal 17-30 weeks radiocarpal

Answer 234

ideal angle = 10-12 degrees true range = 10-47 degrees, metacarphal phalangeal joint range = -3 to 19 degrees

Answer 235

50% satisfactory for partial carpal 75% satisfactory for pancarpal

Answer 236

T-plate secured to radiocarpal bone (distal to not interfere with joint) Can also use cross pins

Answer 237

MC 4 and 5 excessive periosteal rxn with OA in the area up to 33% bone

Answer 238

65% recover in 2 weeks with appropriate diet and controlled exercise on good surface - due to under/over suppelmentation in diet and concrete surfaces with little exercise - usualy 5-27w old, 2:1 male predilection - no evidence of coaptation

Answer 239

61% malignant 20% benign 19% pyogranulomatous inflammation SCC (38%), melanoma (32%), MCT (11%), PNST (7%), and \<5% others With SCC 66% from subungal epithelium (poorer survial) = 1 and 2yr survival 76%, 43% - lung mets more common with melanoma (32%) than others (SCC 13%)

Answer 240

Greyhounds (male\>female) 90% thoracic **digital pads 3&4** (40% had additional foot deformities) mechanical = \>50% return in 2m in Greyhounds, do not return in other species with excision and 1 layer closure

Answer 241

Lateral Ventral Dorsal - allows longer plate and screws (cats) - Long oblique can also be repair with 2-3 lag screws

Answer 242

note Bone hook

Answer 243

Doesn't require perfect contour to maintain reduction

Answer 244

41% associated with SI luxation - 81% good funcitonal outcome 91% LS trunk damage assoicated with cr-med displacement of ilial fx

Answer 245

**Lag screw fixation (1-2 screws)** - \<60% 38% loosen, \>60% 7-8.4% loosen, \>79% none loosend, loosend fixation results in only sl loss recution with little effect on pelvic canal diameter (lat or ventral), (open or **minimally invasive**) **trans-illiosacral rod-** method uses fluoroscopy for placement **single long transsacral screw** is placed to capture both ilial wings, with lag effect on one side and positional effect on the opposite side (ventral) **transilial pinning** **pin and tension band**

Answer 246

77% unilateral SI 85% have concurrent injuries that disable both limbs

Answer 247

Cat: distance of the drill hole in the cat from the cranial margin of the sacral wing is 51% of sacral wing length, just cranial to the C-shaped cartilage.8 The distance from the dorsal margin of the sacral wing is 47% of sacral wing height.8 The sacral wing notch is not useful for screw placement location in the cat Dog: drawing an imaginary line between the dorsocranial and ventral aspects of the sacral wing. A hole is drilled just caudal to this line, approximately 40% from the ventral point on the sacral wing. Sacral wing notch (see Figure 57-17, D). is present in mature dogs and may be palpated along the cranial edge of the sacral wing. The notch is located exactly cranial to the sacral body in dogs

Answer 248

Abaxial = lateral to sacral foramen (includes spinous process) Axial = medial to sacral foramina and ventral to spinous processes Type: I: alar II: foraminal III: transvers IV: avulsion V: comminuted

Answer 249

69% neuro deficits 43% hindlimb defeicits 28-34% - perineal, anal tone, urinary tract 28% tail denervation axial more likely to have defeicits

Answer 250

Diarthroidaidal articulation

Answer 251

1. Acetabular labrum - fibrocartilagenous band that extends from the DAR, ventrally extend across the acetabular notch as the transverse acetabular lig 2. joint fluid 3. periarticular mm (deep, middle, superfical gluteals, iliopsoas, quadratus fermoris, gemelli, internal and external obtrurator)

Answer 252

Left: 10 and 1, right 10 and 2) sm-med = 2.7mm large = 3.5=4.0mm hole from cr to cd through neck of femur suture in figure of 8 limb in abduction and sl. internal rotation

Answer 253

General sucess rate = 85% **Capsulorrhaphy:** 83-90% **Prosthetic capsule technique** = 66-100%, 18% mild and 18% severe lameness **Transposition of the greater trochanter** = 84% **Transarticular pinning** = 80% success, unsatsifactory in 40% dogs \>20kg **Toggle rod stabliazation** = 85%, 88% toe touching at dc, 11% reluxation Other techniques: **Fascia lata loop stabilzation** (1cm wide, passed over acetabulum and through hole in hip/femur), **extra-articular iliofemoral suture placement** (ilium hole -ventral, cr-cd femur, cd-crd under gluteal m (no comp or relux), **transposition of sacrotuberous lig, Femoral head and neck excision arthoplasty, triple pelvic osteotomy, total hip arthroplasty.**

Answer 254

Dorsal approach Reduce hip ventral acetabular lig can be sutured autogenous iliac crest shelf graft to augment acetabular rim

Answer 255

62% not lame 20% severely lame 32% crepitus 48% pain 92% normal range of motion OA progression in 55-62%, more pronouced in heavier dogs Delayed Tx did not worsen prognosis

Answer 256

\<30 degrees angle of reduction with ortalani some recommend using a 20 degree plate only up to 10 months old

Answer 257

Increase by 8 w post-op normalize by 28w post-op

Answer 258

Greater rotation Capsulorrhapy Lembert imbrication

Answer 259

62% Limited by: - cancellous scres in cranial seg - use of longer screws that purchase sacrum?? - strict activity restrict - Ventral plate stablization

Answer 260

Remove most lateral portion of pubis pre-angle TPO plates

Answer 261

use of antibiotic prophylaxis creation of a muscle flap base 1.5 times the width of the ostectomy surface use of the caudal pass of the biceps femoris muscle flap suturing of the muscle flap under minimal tension suturing of the flap to the middle gluteal and vastus lateralis muscles careful identification and protection of the ischiatic nerve (damage reported in 3 dogs post biceps muscle transposition)

Answer 262

Vaccum mixing: Reduces cement porosity, increases fatigue strength evauates funes from OR Pressurization: forces cement into irregularites - increases max stregth of bone/cement interface

Answer 263

Advantages: - longer potential implant life - decreased risk of post-op infection - better implant stability Disadvantages: - Greater risk of femoral fx during reaming - more critical for precise acetabular and femoral reaming to allow good fit

Answer 264

Biomatrix - cemented cup, press-fit stem Zurich (Kyon) - screw in acetabular component, less subsidence, higher complication rate than BFX (17%) HELICA - screw in femoral prosthesis that doesn't extend into diaphysis of femur, screw in acetabular cup.

Answer 265

slightly closed (5-10 degrees) retroverted (10-20 degrees)

Answer 266

Cemented (12-13% overall): luxation (4-5%), aseptic loosening (2-3%), Infection (1-2%), _pulmonary embolism_ (upto 82% but death uncommon), femoral fx, s**ciatic neuroparaxia, medullary bone infarction, neoplasia,** acetabular cup displacement. Cementless: Luxation, fissure fx, acetabular cup displacement, aseptic loosening, **subsidence of stem, lucency at acetabular cup-bone inferace**, **bone infarction,** lameness

Answer 267

3% risk factors: osteopathy iatrogenic bone fissures

Answer 268

Both more common in cemented Similar appearence initialy Later infection = more periosteal reaction, increased **bone lysis, sclerosis**, formaiton of **bone cloacae,** drainaing tracts

Answer 269

Short neck and Bernies

Answer 270

2-5mm not significant, \>5mm significant - undersized stems greater subsidence than large stems in nwutral position or undersized stems in varus - \>85% canal fill less likely to subside Prevent: appropriate sized implant, removal of most of cancellous bone in prox femur If pistoning causing lameness = fresh ream and placment of cement (or remove entirely)

Answer 271

Scrape periosteum from ventral border orgin of rectur femoris to dorsal midline acetabulum. - Equivocal = some relief but variable and prob not permanant - improved visual analog score and precieved pain but GRF no improvement - Poss protective effect on opposite limb - decreased peak vertical force and impluse

Answer 272

Intertrocahnteric osteotomy Pectineus myectomy Shelf arthroplasty Dorsal acetabular rim arthroplasty Ventrodorsal radiographs of a dog with coxa valga and bilateral hip joint subluxation before (A) and after (B) intertrochanteric osteotomy. Coxa valga is accentuated by external rotation of the femur (noted by prominence of the lesser trochanter) in (A). Note how the hip subluxation is resolved in the postoperative view

Answer 273

Tension: lineal transversa (ossesous ridge from head to greater trochanter), femoral neck Compression: greater trocanter and femoral head

Answer 274

internal and external obturator mm. and gemelli

Answer 275

Single physis for 2-3m, then divide into capital physis and trochanteric physis - Capital physis = 25% longitudal growth, forms femoral neck - Trocanteric physis = no growth, shifts that mm. laterally - Closure of both physes begins at 6m, complete by 9-12m dogs, 7-10m cats

Answer 276

Extraosseous: lateral and medial circumflex femoral, caudal and cr. gluteal, iliolumbar Intracapsular: extraossous anastomse to form vascualr ring Intraosseous A. of the lig of the femoral head (epiphyseal blood in cat, not dog)

Answer 277

**medial circumflex femoral a**. (nutrient formen) **Nutrient a.** (asending and desending medullary a) **metaphyseal a.** anastomose with medullary **Periosteal a.** - enter along facies aspera (important puppies, no adults)

Answer 278

Caudal supracondylar tuberosites

Answer 279

lateral supracondylar tuberosity

Answer 280

same as proximal (starts 6m, closes 9-12m dogs, 4m, 7-9m cats) Distal metaphysis: branches of saphenous and descending genicular aa. off femoral a.

Answer 281

1. Alpha numeric based on location, degree comminutation and severity, prognosis): femur = 3, position within femur (1-3 prox-distal), morphology (A= single fx, B= butterfly, C= comminuted), severity and px (1-3, least to most severe) 2. Proximal femur= intracapsular or extracapsular (intracapsular = epiphyseal, physeal, subcapital, transcervical), (extracap = basiler neck, intertrochanteric, subtrochanteric) 3. Metaphyseal = supracondylar 4. epiphyseal = physeal (cats SH type1, dogs SH type 2), condylar (unicondylar or bicondylar)

Answer 282

- 91% in animals \<12m - 70% capital physis

Answer 283

prosthetic joint capsule or iliotrochanteric band (augmentation techniques)

Answer 284

Retrograde (more accurate, but have to dissect fx site) or normograde (if thorugh articular surface need to transect lig = instability) Rec placing 2 **parallel** pins - # pins not associated with OA develop, 1-2 pins = strength to normal, 3 pins increases strength by 30%) Centrally placed pins advanced 75-80% contralateral epiphysis or width pubic bone, eccentric = 65% upto 70% resportion of femoral occurs following ORIF, minimally invasive decreses chance of resorption or segmental collapse

Answer 285

Cats\>dogs Young, overweight, castrated male cats (poss. associated with early castration Histo: viable bone with irregular clusters of chonfrocytes in EC matrix and necrotic cartilage Lag screw fixatoin with antirotational K wire

Answer 286

lateral cortex

Answer 287

Adduction stay in cr lateral fossa max extension

Answer 288

50% pin migration loss of reduction implant failure sciatic neuropraxia neurotmesis

Answer 289

bolts on only one side

Answer 290

83-96% old version = 12% instability and need supplemental implants

Answer 291

Pin tract inflammation 60-80% dogs, 22% cats implant failure fracture Quadriceps contracture 33% dogs, 7% cats non-union

Answer 292

loss 20% femoral length rotaional/valgu/varus malalignment worse

Answer 293

23% cats 14% dogs

Answer 294

Cross pin = 30-45 degrees Rush = 15-20

Answer 295

Radiographic appearance of the proximal femur of a nonchondrodystrophic dog and a chondrodystrophic dog. Note the altered contour of the femoral head, the shortened neck, and the more proximally located greater trochanter with respect to the femoral head (red X) in a chondrodystrophic dog compared with a nonchondrodystrophic dog.

Answer 296

Radiograph of aseptic loosening of a cemented THR

Answer 297

cr/cd meniscotibial ligs for MM and LM intermeniscal lig meniscofemoral lig popliteal tendon **coronary lig** (MM to MCL) medial collateral lig - fused to MM and joint capsule lat collateral lig - separated to LM dt popliteal tendion, loose attach to joint

Answer 298

Collagen fibrils - 3 layers Collagen bundles on surface randomly oriented Outter 2/3 = circumfrential, immermost budles in radial

Answer 299

Perimensical capillary plexus - **medial and lateral genicular aa.**

Answer 300

140 degrees

Answer 301

Extension: MCL limits valgus, LCL and CrCL limit varus Flexion: all limit valgus, LCA and CCLs limit varus

Answer 302

cut caudal meniscaotibial lig = 140% increase in peak contact pressure, 50% decrease in contact area 30% radial width = minial effect (aka partial) 75% radial width and hemimensectomy = sig change in contact mechanics To be functional, meniscus needs \>25% radial width Partial menisectomy did not change contact pressure noted under torn meniscus

Answer 303

Alternatively can TX avulsion with epiphysiodesis - screw in cranial part of epiphysis - caudal continues to go and decreased TPA In 22 dogs: reduction in TPA of 4-24 degrees Eccentric screw = valgus

Answer 304

Ultrasonographic examination of the canine menisci has been reported, and its sensitivity and specificity compared with arthroscopy for the diagnosis of meniscal pathology was 90.0% and 92.9%, respectively high field MRI appears to be a very reliable method for diagnosing meniscal tears preoperatively, with reported sensitivity of 100% and specificity of 94% in a small number of case (low field not, 60% sens and 90% spec)

Answer 305

reported incidence varies from 33.2% to 77% Radial tears of the lateral meniscus have been reported with an incidence of 77%

Answer 306

insufficiency, 33.2% of dogs presented with a meniscal tear diagnosed at the time of the first surgery. The sex distribution was 39.7% neutered males, 32.2% neutered females, 13.7% intact males, and 13.4% intact females

Answer 307

The incidence of postoperative (including both postliminary and latent) meniscal injury has been reported for several surgical techniques; it ranges between 2.8% and 17.4%

Answer 308

27% Exacerbation of lameness in cranial cruciate ligament–deficient dogs was 52% sensitive in identifying moderate to severe meniscal injury

Answer 309

probing enhanced the sensitivity and specificity of all diagnostic methods. An accurate diagnosis obtained by **arthrotomy or arthroscopy was 2.1 to 2.6 or 8.0 times** more likely, respectively, when probing was performed compared with observation alone.

Answer 310

Proximodistal view of a right tibial plateau with illustrations of the classification of meniscal tears. A, intact; B, vertical longitudinal tear; C, bucket handle tear (oblique); D, flap tear; E, radial tears; F, horizontal tear; G, complex tear; H, degenerative tears

Answer 311

a **craniomedial arthrotomy** was most sensitive in **cranial cruciate ligament–deficient stifle joints**, whereas **caudomedial arthrotomy** was most sensitive and had the highest sensitivity and specificity in **stable, cranial cruciate ligament–intact stifle joints**

Answer 312

place blade caudal to the medial collateral lig and aim towards tuber of gerdi (30 degree angle)

Answer 313

modiefied Mayo pattern

Answer 314

r**ecovers resting tension to a greater degree** **higher failure load and greater stiffness** = elongates less under a given load than nylon fishing line biologically inert, has low bacterial adherence and is minimally affected by steam or ethylene oxide sterilization

Answer 315

metallic crimp tube - lower loop elongation, higher load at failure, greater stiffness, and greater initial loop tension compared with nylon leader line secured with a square knot

Answer 316

estimated load applied to the suture is 120 to 600 N

Answer 317

F2 - caudal edge lateral femoral condyle immediately adjacent to distal pole of fabella T3 - caual wll extensor groove

Answer 318

In 363 dogs, 17.4%, 7.2% required a second surgery Factors associated with complications: high body weight and young age 3.9% infection rate - lower rates associatd with suture material other than staples, and post-op oral antibiotics incisional complications 8.8% implant related 2.8% 1.9% post liminary meniscal tear rate

Answer 319

TPA + 5 degrees TPA +7.5 degrees = **caudal tibial subluxation** –Complications more likely to require surgical revision (11.9% vs. TPLO 4.5%)

Answer 320

•Mean mCaPTA (blue angle a) –63.8+/-3.7 lab (TPA 26.2) –63+/-3.9 non-lab (TPA 27) –Intraobserver variability +/- 3.4 degrees –Interobserver variability =/- **4.8** degrees •Another study **+/- 6 degrees due to DJD**

Answer 321

* Complication rate: 18.8-28% * Tibial fracture, intra-articular screw placement, hemorrhage, broken drill bit, fibular fracture, intra-articular jig placement, screw in the osteotomy site, retained surgical sponge, broken holding pin and broken screw * Inflammation, bandage issues, seroma, dehiscence, incisional drainage, incisional infection, hematoma, edema and bruising * Patellar ligament thickening, periosteal reaction, osteomyelitis, postliminary meniscal tear, implant loosening, patellar fracture, septic arthritis, ring sequestrum and luxation of the tendon long digital extensor

Answer 322

•Bilateral single stage TPLO higher risk complications –20-40% complication rate (unless you are Fitzpatrick) –8.5-9.6 fold increase tibial tuberosity fracture •Rockback (remodeling of the subchondral plate of the medial tibial plateau) –1.5 +/-2.2 degrees (range +/-3 to 9) –Less change occurs with locking plates •Infection rate ~ 6%, but much higher in some –Multiple studies have found post antibiotics to be protective –Weight, anesthesia time, locking construct have been loosely associated

Answer 323

•Indications: –Rotation greater than 34 degrees with a 24 blade (12mm) –Rotation past insertion of patellar lig. –Severe tibial valgus/varus/torsion –Patella alta •Surgery: –TPLO cut scored, then wedge scored –TPLO cut completed and pins placed –Wedge completed, tension band/s, plate/s –Bone graft from wedge

Answer 324

* Stifle 135 degrees with no cr. tibial translation * Use transparency or digital software to pick plate **•Can use PTATPA or common tangent method PTACT (preferred)**

Answer 325

Kyon - U of I system Securos - uses screws Rita Leibinger: RAPID - Similar to TTA-2 by Kyon Synthes Others: OssAbility, Vetisco, Everost - Absorbable cage

Answer 326

•Complication rate: 20-59% –12.3-38% major * Meniscal tears, infection, medial patellar luxation, tibial fractures and implant failure * Major meniscal tears, unknown if postliminary (meniscal release) or latent –11.3-14% requiring reoperation •Similar complications TPLO + medial patellar luxation, long digital extensor transection and issues with gap healing

Answer 327

•Patellar ligament insertion/tibial crest –Longer crest with higher insertion may be advantageous * Smaller = lesser buttress support, less area for force distribution aka possible fracture * TPA –~30 degree (possibly less) cut off due to cage size –Hyperextension * Cannot correct ALD * Good for concurrent MPL

Answer 328

* Similar to TTA in concept * Partial frontal plan osteotomy with distal cortex intact * Wedge angle = 2/3 or 0.6x angle between patellar ligament and a line perpendicular to the TP (CA) + 7.3 –Or TPA -5 degrees use if above formula \<0 –Or TPA -12 degrees if small correction needed PTA close to 90 degrees •Proposed advantages: –Minimal change to articulating surface –Small osteotomy gap –No loss limb length –“Low technical difficulty’ •Complication rate 23-36% –Tibial tuberosity fracture, infection, postliminary tears •Intra-op tibial tuberosity fracture occurred in 23% Overall similar complications as TTA and TPLO combined

Answer 329

* \> 1yr outcomes TPLO (65), TightRope (79) and TTA (18) * TTA greater rates of complications and meniscal tears than TR or TPLO, TPLO had greater than TR * Similar percent function at 1 year –More TPLO and TR cases reached full function than TTA •Conclusions: TPLO and TR better than TTA but each had high long-term success. TR highest safety to efficacy ratio

Answer 330

included a cranially positioned osteotomy, a partially intact cranial cruciate ligament in conjunction with a cranially positioned osteotomy, and postoperative tibial tuberosity fracture.

Answer 331

1, **Coxa vara.** 2, Distal femoral varus and genu varum. 3, Shallow trochlear groove with poorly developed or absent medial ridge. 4, Hypoplastic medial femoral condyle. 5, Medial displacement (torsion) of the tibial tuberosity associated with internal rotation of the tibia at the stifle joint. 6, Proximal tibial varus. 7, Internal torsion of the foot, despite external torsion of the distal tibia.

Answer 332

frequency and distribution of medial and lateral patellar luxation in 124 dogs, 82% of cases were found to be developmental. In small-breed dogs, luxation was medial in 98% of cases, and in only 2% it was lateral; the female-to-male ratio was 1.5 : 1.153 In another retrospective study of 134 dogs, medial patellar luxation was found in 127 dogs (95%), and lateral luxation was identified in 7 dogs (5%).7 Bilateral medial patellar luxation is common, occurring in 50%29 to 65% of cases

Answer 333

Deviation of the direction of force of the quadriceps femoris muscle can be calculated and is referred to as the Q-angle.185 Utilizing MRI, the Q-angle was measured in dogs with medial patellar luxation referencing the origin of the rectus femoris muscle, the deepest point of the trochlear groove, and the attachment of the patellar ligament on the tibial tuberosity.185 The average Q-angle of normal dogs was 10.5 degrees; it was 12.2 degrees in dogs with grade I medial patellar luxation, 24.3 degrees in dogs with grade II medial patellar luxation, 36.6 degrees in dogs with grade III medial patellar luxation, and 19.3 degrees in dogs with cranial cruciate ligament rupture

Answer 334

oncurrent rupture of the cranial cruciate ligament is present in 15% to 20% of the stifle joints of middle-aged and older dogs with chronic medial patellar luxation

Answer 335

Trochlear sulcoplasty (abrasion trochleoplasty) - periosteal graft ( fill with fibrocartilage in 4w vs 40w) chondroplasty trochlear wedge block recession

Answer 336

increased **proximal patellar depth** **increased patellar articular contact** with the recessed proximal trochlea recession of a larger percentage of the **trochlear surface area** greater resistance to patellar luxation in an extended position as compared with trochlear wedge recession

Answer 337

coxa vara (a decreased angle of inclination of the femoral neck) and a diminished anteversion angle (relative retroversion) are the underlying skeletal abnormalities

Answer 338

the prevalence of medial patellar luxation in medium-size dog breeds was 81%, in large breeds it was 83%, and in giant-breed dogs it was 67%,

Answer 339

large-breed dogs with an L:P ratio greater than 1.97 were considered to have patella alta

Answer 340

The femoral torsion angle (anteversion angle)

Answer 341

If no tibial torsion is present: TTT and LFS TPLO with internal torsional correction combined with a de-rotational proximal tibial osteotomy TTTA lateral translation of the tibial tuberosity segment following TPLO/CCWO (in this case, a cranial closing wedge or a simple osteotomy at the exit of the tibial plateau leveling osteotomy caudally can be used to isolate the tibial tuberosity segment) (see Figure 62-47, A–D)373; tibial closing wedge osteotomy and TTT

Answer 342

Verbrugge bone clamp

Answer 343

Fractures of the patella can be classified into nondisplaced or minimally displaced apical, basilar, or body fractures displaced transverse body fractures comminuted fractures

Answer 344

the lesion is most commonly located on the axial (medial) aspect of the lateral femoral condyle (96% of cases).251 In some cases, the lesion may be located on the axial (lateral) aspect of the medial femoral condyle (4%)

Answer 345

proper angle (135 to 140 degrees for dogs, and 120 to 125 degrees for cats)

Answer 346

The tibia has four separate epiphyses: proximal epiphysis (40% growth), tibial tuberosity epiphysis, distal epiphysis (60% grpwth), and medial malleolar epiphysis between 6 and 8 months in large-breed dogs), the proximal epiphysis fuses to the tibial tuberosity epiphysis (apophysis apophyseal growth plate normally closes relatively late in the development of the dog (\>12 months in large-breed dogs piphysis of the medial malleolus fuses to the distal tibial epiphysis very early in development (4 to 5 months in large-breed dogs

Answer 347

**nutrient artery and the periosteal vessels** derived from the **cranial tibial artery**. The nutrient foramen is located in the caudolateral edge of the proximal one third of the diaphysis. Within the medullary canal, the **nutrient artery divides into proximal and distal branches** that anastomose with the metaphyseal arteries at each end. The fibular head is supplied by a **branch of the cranial tibial artery**, and the fibular body is supplied by the **nutrient artery derived from the peroneal artery.**

Answer 348

Proximal, diaphyseal, and distal fractures accounted for approximately 1%, 83%, and 18% of fractures in two studies by Boone (multiple locations involved in some fractures), and for 7%, 72%, and 20% of fractures in a study by Unger

Answer 349

The pin selected should fill approximately 30% to 40% of the diameter of the medullary canal

Answer 350

sustentaculumm tali - medial side tuber calcanei

Answer 351

Thickended tarsal fascia = tendon sheath flexor helicus longus, saphenous, plantar n. Medial tibial collateral (3)= long part (med malleous-1st tarsal: taut extension), tibiocentral (taut extension), **_tibiotalar_** (taut flexion, most substanial) Lateral collateral ligment (fibular)(3) = long lateral (taut extension), c_alcaneofibular short_ (taut extension), **talofibular** short (taut flexion) Plantar (3) = middle plantar (calcan - 4th tarsal - MT4/5), medial plantar (sustentaculum tali - tarsoMT joint), lateral plantar (cd calcaneus - long collateral -MT5) (Long lig taut extension, underlined most improtant to fix)

Answer 352

Cr tibial - dorsal pedal a. - dorsal MT aa. (lateral and dorsal) plantar br. saphenous a. (medial and plantar) venous med and lat saphenous

Answer 353

Tibial n. (sciatic) - medial plantar - lateral plantar Common peroneal n (sciatic) - superficial peroneal - deep peroneal Saphenous (br femoral) = cutaneous innervation to dorsomedial tarsus/metarsus

Answer 354

ROM: dog 39-164 degrees, cat 22-167 angle: dog 135-145, cat 115-125

Answer 355

calcaneal fx (right tarsus) central tarsal bone (often concurrent, right tarsus) - 79% all injuries in tarsus (allows collapse and hyperextension of join) 3rd tarsal bone - dorsal slab fx, 20% incidence when looking at tarsal fx types in greyhound

Answer 356

I: nondisplaced doral slab II: displaced dorsal slab III: large displaced medial (rarest) IV: medial slab with dorsal slab (most common) V: comminuted fx 75% are IV or V Ideally lag screws for I-IV. Extension splint/external coaptation for types 1-II, V (minimal chance race again, but good fxn)

Answer 357

Medially (talus) = body and head Lateally (calcaneous) = coracoid process and distal calcaneous

Answer 358

Hyperextension of the calceneoquartal and talocalcaneocentral joints (aka prox. intertarsal joint)

Answer 359

Shetland sheepdogs and collies Arthrodesis of **calcaneoquartal joint** = transfixation pin an tension band, compression screw from calcaeus to 4th tarsal, lateral plate, 35 cases with lag screw +/- tension band = 2 fail by screw breakage

Answer 360

Pin and tension band transfixation pin multiple pins lateral bone plate Transarticular ESF without removal of cartilage = ankylosis

Answer 361

pair gastrocnemius superfical DFT common tendon = semitendinosus, gracilis and biceps femoris

Answer 362

Locking loop or 3 loop pulley immoblize tarsus - calcaneotibial screw (3/38 broke), transarticular ESF, cast/splint

Answer 363

Final dissection of the right pelvic limb. 1, Adductor longus muscle; **2, quadrates femoris muscle**; **3, external obturator muscle; 4, internal obturator muscle; 5, gemelli muscle;** 6, superficial gluteal muscle; 7, middle gluteal muscle; 8, deep gluteal muscle; 9, **articularis coxae muscle**; 1**0, partially severed origin of the rectus femoris muscle;** 11, tensor fasciae latae muscle; 12, biceps femoris muscle; 13, semitendinosus muscle; 14, semimembranosus muscle; 15, adductor muscle; **16, abductor cruris caudalis muscle**; 17, vastus lateralis muscle; 18, sartorius muscle (cranial belly); 19, sartorius muscle (caudal belly); 20, sciatic nerve; 21, acetabulum; 22, head of the femur; 23, superficial circumflex iliac artery.

Answer 364

Clinical photograph of case in Figure 65-20, following interdental wiring and intraoral splinting. Note that the bis-acryl composite splint was applied primarily on the lingual surfaces of the mandibular teeth to allow closure of the mouth.

Answer 365

Bones of the skull, dorsal aspect.

Answer 366

Bones of the skull, hyoid apparatus, and laryngeal cartilages, lateral aspect

Answer 367

Cranial (A–B) and lateral (C) views of the canine skull, which is transilluminated to reveal the buttressing. The lines drawn indicate the horizontal (A) and vertical (B) buttresses of the maxillofacial region of the canine skull (compare with Figure 67-4). The three maxillofacial buttresses can be described as a combination of these horizontal and vertical buttresses (C). The **nasomaxillary (medial)** buttress is seen **rostrally**, the **zygomaticomaxillary (lateral)** buttress is seen caudally, and the **pterygomaxillary (caudal)** buttress is shown with the dashed line Caudal = lacrimal, palatine and pterygoid bones Can reconstruct facial frame with 2/3 butresses (rostal/medial and lateral)...if butresses not compromised does not need to be fixed

Answer 368

An intraosseous wire can adequately secure two opposing bone fragments as a rigid suture (and also compress the fragments together [arrows]). B, With an oblique fracture line or a curved section of bone, or when the cortex is thin, overriding of the bone fragments (arrows) often occurs. C, To prevent such malreduction, a Kirschner wire can be placed across the fracture site (as a “skewer-pin”) to prevent overriding, and a figure of eight wire is placed over the ends of the skewer-pin (compare with Figure 67-13, A–B). D, Alternatively, a Kirschner wire may be used as an external “splint,” where its position on the outer surface of the bone serves as an anchor to multiple wires fastened to each comminuted bone fragment (compare with Figure 67-13, C–D).

Answer 369

Titanium low profile (.7-1mm thick) 1x4.8, 1.3 x 5 (mini), 1.5 x 6.5 (intermediate) for 2.0mm (large) system Low elasticity, high deformability deformatino occurs in connecting bridge not screw holes Sizes: 1, 1.3, 1.5, 2, 2.4, 3, 4 2.0mm screw with 1.4 or 1.5mm core Screw instertion upto a 20 degree angle from the plate Drill holes usually are made of the same diameter of the screw core to obtain a more secure fit between the screw-bone interface (as opposed to standard plate fixation, where screw holes generally are 0.1 mm larger than the screw core diameter).

Answer 370

Typical Total and Differential Cell Counts for Canine Synovial Fluid in Normal Joints and Joints With Osteoarthritis, Rheumatoid Arthritis, Nonerosive Immune-Mediated Polyarthritis (IMPA), and Infective Arthritis

Answer 371

Nonerosive IMPA - **Idiopathic** immune-mediated polyarthritis groups I to IV - **Polyarthritis-polymyositis syndrome** - **Systemic lupus erythematosus** and systemic lupus erythematosus-related disorders - **Drug-induced** immune-mediated polyarthritis - **Breed-associated** immune-mediated polyarthritis Erosive IMPA: - Rheumatoid - Other: PA in Greyhounds (young dogs), feline chronic progressive PA (periosteal proliferation)

Answer 372

Type 1: 50% dx of exclusion (stiff, pyrexic, lymphadenopathy, neutrophilic lekocytosis) = chemotherapeutic immunosupression (pred) cure in 56%, 15% die, 31% relapse. Type 2: 25%: associated with infection remote from joint. May or maynot resovle with infection treatment Type 3: GI disease (15%) Type 4: neoplasia

Answer 373

seminoma mammary, renal, tonsillar carcinoma sertoli cell tumor leiomyoma

Answer 374

Sulfonamides penicillins erythromycins lincomycin cephalosporin Onset 7-21 days post starting. PMNS without toxic changes in synovial fluid. Improve 1-3 days afer withdrawl Large breed dogs and dobies

Answer 375

skin, mucocutaneous ulceration serositis (pleuritis) immine complex glomerulonepropathy Anemia (hemolytic), thrombocyopenia, leukopenia menigitis polymyositis KCS, retinopathy, Uveitits

Answer 376

Chinese Shar Pei (familial amyloidosis- shar pei fever, poor px renal failure) Japanese Akita - adolescnece, aseptic menigitis

Answer 377

Collective term for antibodies (IgM and IgA) with specificty for Fc receptor of IgG

Answer 378

Classical rheumatoid arthritis is diagnosed when seven criteria are satisfied, and definite rheumatoid arthritis when five are satisfied. With criteria 1 through 5, the joint signs should be present for at least 6 weeks. In addition, two of criteria 7, 8, and 10 should be satisfied; these three criteria have been considered probably the most specific for canine rheumatoid arthritis

Answer 379

Erosive PA Periostal new bone Negative for RF Enthesopathies Disease hocks and carpus Usually neg. RF and ANA, but positve for syncytial forming cirus (FeSV) and FeLV

Answer 380

Dogs: staph (auerus and intermedius) and beta hemolytic strep Cats: Pasturella mutocida and bacteroides Risk factors = previous surgery and exisiting joint disease Other forms infective arthritis = Borrelia (Lyme), Bacterial L forms, mycoplasma arthritis, Protozoal, fungal, rickettsial, mycobacterial

Answer 381

1= superficial/tangential 2= transitiional 3= radiate tide mark 4= calcified