Lecture 3 Amputation/Arthrodesis

Question 1

Define arthrodesis:

Answer 1

surgical treatment leading to joint fusion

Question 2

Define ankylosis:

Answer 2

non surgical condition leading to joint fusion

Question 3

Define amputaiton

Answer 3

removal of an appendage or a portion thereof

Question 4

What are the Indications for Arthrodesis?

Answer 4

Goal is to improve/eliminate pain
Irreparable fx of joint
chronically unstable joints- carpus/tarsus
chronic, severe, joint disease of any nature
Neurological injury

Question 5

Why does neural injury usually result in limb amputation?

Answer 5

no cutaneous sensation in palmar/plantar region; self mutilation usually occurs-> amputation

Question 6

What joints are amendable to arthrodesis?

Answer 6

scapulohumeral joint
elbow
carpus at antebrachial joint
Carpo-metacarpal joint
phalanges
stifle
tarsus
vertebal bodies

Question 7

What are the alternatives to arthrodesis?

Answer 7

medical management

total joint replacement

Excision by arthroplasty ie FHO

amputation

Question 8

What are the principles of arthrodesis?

Answer 8

removal of articular cartilage
bone graft
fused at anatomical standing angle
rigid fixation

Question 9

Why is articular cartilage removed during arthrodesis?

Answer 9

exposes subchondral bone
speeds healing process
blood clot, stem c`ells for bone healing
remove barrier to bone bridging
increases blood flow at site of fusion

Question 10

Why are bone grafts included in arthrodesis?

Answer 10

speed up callus formation -> decrease implant fatigue

Question 11

What are the functions of bone graft?

Answer 11

Ostogenesis
Osteoconduction
Osteoinduction
Osteopromotion

Stimulate bone healing, and induce cells to enter

Question 12

What are the common graft sources?

Answer 12

autogenous- cancellous bone

allograft- demineralization

Question 13

What are some of the common sources of autogenous bone grafts?

Answer 13

proximal humerus- tons here
ilial wing
distal femur
proximal tibia

Question 14

Whappens if you fuse the joint and it is too flexed or too extended?

Answer 14

too flexed-> shortening of the limb

too extended-> lengthening of the limb

puts more stress/strain on the implants, loosening/breaking

Question 15

T/F

In both internal and external if rigid fixation is not used, the arthrodesis will not heal

Answer 15

TRUE

Question 16

What are the components/goals of external coaptation?

Answer 16

Typically 6-8 weeks
4-6 w/ splint
2-4 w/ soft padded wrap

Supplement stability during bone healing

Question 17

What is the primary goal of external coaptation?

Answer 17

GOAL is to prevent implant fatigue and failure

Question 18

What are the specific indications for carpal arthrodesis?

Answer 18

Carpal hyperextension injuries
shearing injuries
carpal luxation of antebrachial or carpometacarpal

Question 19

What are do you look for on radiographs with regards to evaluation prior to performing arthrodesis?

Answer 19

Evaluate for other bony abnormalities

measure for implant size/placement

Question 20

What radiographic views must be included for arthrodesis evaluation and why?

Answer 20

Stressed views

help determine where luxation is occurring

may help determine how much of carpus to fuse

pan vs partial carpal arthrodesis

Question 21

What are the specific indications of pantarsal arthrodesis?

Answer 21

severe loss of bone and soft tissues

rupture of the common calcaneon tendon

talocrural

Question 22

What is the max time a tourniquet can be applied ?

Answer 22

1.5 hours

after that start to devitalized tissue/ increase risk of infection

Question 23

What are the complications of arthrodesis?

Answer 23

infection
implant breakage/loosening
fx of bone above/below implant esp stifle, need long implant to span bone adjacent to the joint
irritation by the plate
removal may be necessary

Question 24

What is the outcome of arthrodesis?

Answer 24

pain free
functional limb
will always have gait abnormality

Question 25

When is amputation a considered tx?

Answer 25

when other methods are deemed unsuccessful/too risky a palliative tx for intractable pain when the owner makes an informed decision for their pet

Question 26

What are the physical indications for amputation?

Answer 26

neoplasia- bone tumors, soft tissue tumors severe vascular injury leading to ischemia- gangrene, frostbite trauma etc Neurological injury- partial/complete paralysis of limb, self mutilation intractable pain for other reasons

Question 27

What are the principles of amputation?

Answer 27

Gentle tissue handling careful hemostatsis respect nervous tissue close dead space aggressive pain management

Question 28

What is one of the most important things to consider prior to amputation?

Answer 28

the ability of the animal to ambulate after Sx

Question 29

What makes a candidate good for amputation?

Answer 29

ability to ambulate of remaining legs-> do orthopedic/neruo exam educated owners

Question 30

What are the 3 types of amputation?

Answer 30

Front limb Hind limb Other digit / tail

Question 31

What are the types of front limb amputations?

Answer 31

Forequarter amputation- entire limb Shoulder dis-articulation amputation Mid humeral amputation

Question 32

What are the types of hind limb amputation?

Answer 32

Coxofemoral dis articulation mid femoral dis articulation- cut femur remove everything below it; they are both essentially the same functionally

Question 33

T/F Declawing is not technically considered an amputation

Answer 33

FALSE nailbed is in distal part of bone, take whole thing

Question 34

What essential procedures must completed during limb amputation?

Answer 34

double ligation of major arteries and veins careful closure of dead space cosmesis

Question 35

What analgesia is provided for ampiutation

Answer 35

IV opioids, lidocaine, ketamine Epidural: provides central analgesia for animal Direct nerve block: epidural bupivacaine Local anesthetics- soaker catheters = CRI or intermittent dose of bupivacaine or lidocaine- have fenestrations in catheter that will give constant rate of infusion

Question 36

What are the general complications w/ anesthesia?

Answer 36

hemorrhage/ seroma, incision site infection/incision dehiscence phantom pain incomplete tumor excisions

Question 37

T/F Amputation of a neoplastic limb is usually curative w/o other medical management

Answer 37

FALSE lifespan is limited, must do in conjunction w/ chemotherapy

Question 38

T/F Both amputation and arthrodesis are viable methods for relieving pain in dogs, and are not viable in cats

Answer 38

FALSE its fine for both