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Flashcards in 61.Femur Deck (20):
1

Minimal cortices with plate rod construct using Compression plate vs locking plate

Min 4 cortices in prox and distal fragment and accurate contouring if compression plateMin 3 cortices in ea fragment if locking plate

2

Forces resisted for applying IM pin and cerclage to femur

IM pin- resist bending (aim 70 % canal width)Cerclage-resist rotation & compressionMin 2 wires Fracture length 2-3x diameter of bone

3

T/FIM pin and cerclage are contraindicated in immature dogs

TrueWill heal, however, results in abnormal development in proximal femur and coxofemoral joint (hip dysplasia)

4

Static vs dynamic ILN

Static ILN-bolts above and below fractureDynamic ILN-bolts only on one side of fx Prefer static for full biomx advantage of ILN USE TWO LOCKING DEVICES IN PROX AND DISTAL FRAGMENT bolts>screws

5

Goal in overreduction of distal femoral fx fragment

Dogs have natural caudal bowing Overreduce ~12 degrees to seat IM pin or ILN into distal metaphysis wo penetrating cranial cortex or stifle joint Not needed in cats bc straighter distal femur

6

Reasons against ESF for femur fractures

Large thigh musclesClose to abdominal body walllimited to type Iacan increase design with hybrids, tie ins

7

Complications w ESF for tx of femur fx

60-80% dog pin tract inflammation and discharge22% cat

8

The most common bone affected by nonunion and osteomyelitis

Femoral diaphysis despite that the majority of fracture (83%) are closed

9

Quadriceps contracture

Min to nonwt bearing post opFibrous adhesion Btwn muscle and callus, progressive ankylosis and hyper extension

10

Complications w supra condylar femur fx

DJDimplant associated lameness (patella)Secondary fxMalunionPatella luxQuadriceps contracture

11

Most common physical injury in the dog

Distal femoral physeal fractures 60% of all distal femur fxdogs prone to type II bc caudal metaphyseal PEGScats type I

12

Rush pinning distal femoral physis fx

Aka dynamic pinning Longer pins, slight bentInserted steeper (15-20 vs 30-45 degrees)Predrill insertion pointDeflect off the opposite cortex and hand chuck across fx

13

Typical signalment for felines w capital physeal dysplasia

Young OverweightMaleCastrated

14

blood supply to the femoral head dogs vs cats

the artery of the ligament of the femoral head does NOT contribute to the epiphyseal blood supply in DOGS. Dogs rely on epiphyseal blood supplyCATS the artery of the ligament of the femoral head DOES contribute and may explain decr risk of aseptic necrosis of the femoral neck (Legg_Calve) in cats

15

approaches to the proximal femur

1. craniolateral approach2. dorsal approach with osteotomy of greater trochanter (GORMAN APPROACH)3. dorsal approach with tenotomy of deep gluteal

16

biological and mechanical considerations for fractures involving the proximal femur

1. minimal bone stock2. fragile vascular supply3. potential for articular involvement4. residual growth potential of capital physis (25%)5. eccentric loading of femoral head

17

retrospective studying looking at pin number and outcome OA/femoral head and neck resorption conclusions

following capital physeal fracture1-2 pins vs 3-4 pins NO SIGN DIFFERENCE in OA progression or resorption

18

biomechanics study of 1, 2, or 3 pins for capital physeal fractures

1 and 2 pins were biomechanically similar to the intact physis BUTaddition of 3rd pin increased repair 29% strongerrecommend min 2, max 3

19

percentage of resorption seen in capital physeal fractures treated with internal fixation

70% have resorption of the femoral neckapple core effect

20

signalment of capital physeal dysplasia or epiphysiolysis

youngoverweightcastrated male (potential for early neutering to cause delayed physeal closure)cats

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