61.Femur

Question 1

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

Answer 1

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

Question 2

Forces resisted for applying IM pin and cerclage to femur

Answer 2

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

Question 3

T/FIM pin and cerclage are contraindicated in immature dogs

Answer 3

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

Question 4

Static vs dynamic ILN

Answer 4

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

Question 5

Goal in overreduction of distal femoral fx fragment

Answer 5

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

Question 6

Reasons against ESF for femur fractures

Answer 6

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

Question 7

Complications w ESF for tx of femur fx

Answer 7

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

Question 8

The most common bone affected by nonunion and osteomyelitis

Answer 8

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

Question 9

Quadriceps contracture

Answer 9

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

Question 10

Complications w supra condylar femur fx

Answer 10

DJDimplant associated lameness (patella)Secondary fxMalunionPatella luxQuadriceps contracture

Question 11

Most common physical injury in the dog

Answer 11

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

Question 12

Rush pinning distal femoral physis fx

Answer 12

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

Question 13

Typical signalment for felines w capital physeal dysplasia

Answer 13

Young OverweightMaleCastrated

Question 14

blood supply to the femoral head dogs vs cats

Answer 14

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

Question 15

approaches to the proximal femur

Answer 15

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

Question 16

biological and mechanical considerations for fractures involving the proximal femur

Answer 16

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

Question 17

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

Answer 17

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

Question 18

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

Answer 18

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

Question 19

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

Answer 19

70% have resorption of the femoral neckapple core effect

Question 20

signalment of capital physeal dysplasia or epiphysiolysis

Answer 20

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