Lecture 3 Amputation/Arthrodesis Flashcards
Define arthrodesis:
surgical treatment leading to joint fusion
Define ankylosis:
non surgical condition leading to joint fusion
Define amputaiton
removal of an appendage or a portion thereof
What are the Indications for Arthrodesis?
Goal is to improve/eliminate pain
Irreparable fx of joint
chronically unstable joints- carpus/tarsus
chronic, severe, joint disease of any nature
Neurological injury
Why does neural injury usually result in limb amputation?
no cutaneous sensation in palmar/plantar region; self mutilation usually occurs-> amputation
What joints are amendable to arthrodesis?
scapulohumeral joint elbow carpus at antebrachial joint Carpo-metacarpal joint phalanges stifle tarsus vertebal bodies
What are the alternatives to arthrodesis?
medical management
total joint replacement
Excision by arthroplasty ie FHO
amputation
What are the principles of arthrodesis?
removal of articular cartilage
bone graft
fused at anatomical standing angle
rigid fixation
Why is articular cartilage removed during arthrodesis?
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
Why are bone grafts included in arthrodesis?
speed up callus formation -> decrease implant fatigue
What are the functions of bone graft?
Ostogenesis
Osteoconduction
Osteoinduction
Osteopromotion
Stimulate bone healing, and induce cells to enter
What are the common graft sources?
autogenous- cancellous bone
allograft- demineralization
What are some of the common sources of autogenous bone grafts?
proximal humerus- tons here
ilial wing
distal femur
proximal tibia
Whappens if you fuse the joint and it is too flexed or too extended?
too flexed-> shortening of the limb
too extended-> lengthening of the limb
puts more stress/strain on the implants, loosening/breaking
T/F
In both internal and external if rigid fixation is not used, the arthrodesis will not heal
TRUE
What are the components/goals of external coaptation?
Typically 6-8 weeks
4-6 w/ splint
2-4 w/ soft padded wrap
Supplement stability during bone healing
What is the primary goal of external coaptation?
GOAL is to prevent implant fatigue and failure
What are the specific indications for carpal arthrodesis?
Carpal hyperextension injuries
shearing injuries
carpal luxation of antebrachial or carpometacarpal
What are do you look for on radiographs with regards to evaluation prior to performing arthrodesis?
Evaluate for other bony abnormalities
measure for implant size/placement
What radiographic views must be included for arthrodesis evaluation and why?
Stressed views
help determine where luxation is occurring
may help determine how much of carpus to fuse
pan vs partial carpal arthrodesis
What are the specific indications of pantarsal arthrodesis?
severe loss of bone and soft tissues
rupture of the common calcaneon tendon
talocrural
What is the max time a tourniquet can be applied ?
1.5 hours
after that start to devitalized tissue/ increase risk of infection
What are the complications of arthrodesis?
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
What is the outcome of arthrodesis?
pain free
functional limb
will always have gait abnormality
When is amputation a considered tx?
when other methods are deemed unsuccessful/too risky
a palliative tx for intractable pain
when the owner makes an informed decision for their pet
What are the physical indications for amputation?
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
What are the principles of amputation?
Gentle tissue handling
careful hemostatsis
respect nervous tissue
close dead space
aggressive pain management
What is one of the most important things to consider prior to amputation?
the ability of the animal to ambulate after Sx
What makes a candidate good for amputation?
ability to ambulate of remaining legs-> do orthopedic/neruo exam
educated owners
What are the 3 types of amputation?
Front limb
Hind limb
Other digit / tail
What are the types of front limb amputations?
Forequarter amputation- entire limb
Shoulder dis-articulation amputation
Mid humeral amputation
What are the types of hind limb amputation?
Coxofemoral dis articulation
mid femoral dis articulation- cut femur remove everything below it;
they are both essentially the same functionally
T/F
Declawing is not technically considered an amputation
FALSE
nailbed is in distal part of bone, take whole thing
What essential procedures must completed during limb amputation?
double ligation of major arteries and veins
careful closure of dead space
cosmesis
What analgesia is provided for ampiutation
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
What are the general complications w/ anesthesia?
hemorrhage/ seroma,
incision site infection/incision dehiscence
phantom pain
incomplete tumor excisions
T/F
Amputation of a neoplastic limb is usually curative w/o other medical management
FALSE
lifespan is limited, must do in conjunction w/ chemotherapy
T/F
Both amputation and arthrodesis are viable methods for relieving pain in dogs, and are not viable in cats
FALSE
its fine for both
