Friday, May 16, 2008

AMPUTATION

AMPUTATION

-absence of all part of a limb asa a result of surgery,trama,or disease
-aka removal of a limb through the continuity of a bone
-LE-most common cause of amputation is PVD
-UE-most common cause of amptation is trauma


General Classisfication of Amputation:
A.CONGENITALAMPUTATION
-occurs in utero
B.ACQUIRED AMPUTATION
-traumatic
-ischemic-due to PVD
-surgical-done for cosmetic purposes(amputaion secondary to polydactyly)

*can also be classified as:
A.Major-amputation above MCP/MTP
B.Minor-amputation through distal to MCP/MTP

Indications:
1. Vascular accident or disease
-when infection is imminent and wound healing is uncertain
2.Infection
-Most common indication for amputation (i.e.gangrene)

a. Acute-threatens invasion to other parts of the body;endangering life
b. Chronic-source of toxic absorption (i.e. osteomyelitis)
3.Congenital anomaly
-amputation is due to failure of the limb to develop fully
-surgical amputation - is indicated to improve,to form/shape the deformed/deficient limb so that fitting of an artificial limb is possible
4.Trauma
-results in destruction of blood supply or results in extensive destruction where reconstructive is no longer feasible
5.Tumor
-If benign amputationis indicated only if it will result in functional limb
-If malignant,amputation is done to prevent further spread of malignancy
6.Thermal,Chemical or electrical in injury (severe burn inury)
-Injuries from extreme heat /cold (frostbite) can also lead to amputation


SITES OF AMPUTATION:
A.UPPER EXTREMITIY AMPUTATION:
1.Amputation thru the fingers (ray amputation)
3 Basics functions:
a. grasp
b. pinch
c. hook

Thumb
a. imporatntin grasp, vital in pinch
b .40%-50% function loss when thumb is amputated
Index and middle finger
a. most impotant in all 3fucnctions because of their proximity o the thumb
b. srtrogest and most stable
c. 20% index finger and 20% middle finger
Ring and little finger
a. 10% each for ring finger and little finger too
b. provides mobility
c. aids in the combineddexterity of all fingers

2.Amputation about wrist
Advantages:
a. pronation are preserved
b .greater stump adaptability (not as cumbersome/uncomfortable compared to above
the elbow amputation)
c. retains natural wrist flexion and extension if amputation is done thru the carpals

Amputation thru the CARPALS ( midcarpal amputation) with palmar ski
a. easil;y performed since radiocarpal joint is not invaded
b .rounded to smooth contour and covered with palmar skin
c .retains the wrist flexion
Disarticulation of the wrist at the radiocarpal joint

3.Amputation thru the lower third of the forearm
a. poor since the skin is thin and underlying soft tissue are largely tendons and fascia
b. poor since the circulation is not good;the stump is frequently cold,tender and cyanotic
c. secondary skin breakdown is common
d. not adaptable with use of prosthesis(poor muscular padding)
e. NO pronation /supination

4.Amputation at the junction of the middle and lower third of the forearm
a. IDEAL TRANSRADIO-ULNAR STUMP ( functionally and cosmetically)
b. Ideal length:7-8 inches from the tip of the olecranon process to the end of the stump
c. circulation is good in this area
d. full elbow flexion is very possible

5.Amputation above the ideal
a.forearm/elbow flexion may be normal but can be impaired in either its range or
strength
6.Amoputation through the humerus
a.Disarticulation thru the elbow joint
a. at the end of the humero-ulnar and the humero-radial joint
b. retains near normal of the shoulder
b.Transcondylar amputation
a.amputation thru epicondyles(long above the elbow stump)
b. hard to fit with a prosthesis
c.Through the supracondylar region
a.still considered a long above the elbow stump
7.Amputation above the supracondylar region
a. IDEAL TRANSHUMERAL STUMP
b. Ideal length 8 inches from the acromion process to the end of he stump
b. most functional stump




8.Amputation about the shoulder
a. functional prosthesis cannot be worn ( worn only for cosmesis,impractical)
b. 2 possible levels
a. thru the surgical neck of the humerus
b.disarticulation at the scapulohumeral jt
9.Forequarter Amputation (shoulder girdle/interscapulothoracic amputation
a. At the interval between the scapula and the thoracic wall
b. All shoulder functions are obliterated


B. Lower Extremity Amputations
1.Foot amputations
-balance between muscle and bony support is lost
A.Toes
- function in tip-toeing
- amputation results in loss of push-off
Big /great toe
-has supporting role in stance
-fulfills a vital function in gait,principlal wt bearing element in the final
phase of hell-off (adds rhythm and agility)
-when amputated,the loss is felt more during rapid walking and
running
Lesser toes
-principal functions:
1. stabilize the foot by widening the base of support during squatting
and tip-toeing
2.assist the great toe in push-off and heel-off during rapid gait and running
-amputation at the 2nd toe in the proximal phalanx results in hallux valgus deformity
B. Metatarsals
-balance and weight distribution are disturbed in the direct proportion to the extent and location of loss
C. Above metatarsals
-stump is worthless even as support for the prosthesis
2.Amputation thru the metatarsal and ankle joint
a. SYME’S AMPUTATION
-transmalleolar amputation
-designed for weight bearing at the end of the stump
-provides stability for prosthesis,maybe used without prosthesis
b. BOYD’s Amputation
-weight bearing over calcaneous following removal of remaining bones of the foot and
calcaneo-tibial arthrodesis
c. Vasconecelos Amputation
-done if use of an artificial limb is not anticipated
-midtarsal amutation combined with tibiotalar and subtalar arthrodesis and section of the inferior surface of the calcaneous.
d. Pirogoff’s Amputation
-principle of arthrodesis of the tibia to the calcaneous after the latter has been rotated forward and upward 90degrees (anteversion)
-unsuccesful for prosthetic fiiting due to its irregular shape


e. Listfranc’s Amputation
-disarticulation of the foot through the tarsometatarsal joint
-falls into moderate equines deformity
-like the pirogoff’s amputation,unsuccessful for prosthetic use
f. Chopart’s Amputation
-thru the transverse tarsal joint (talonavicular/calcaneocuboid)
-intended for end bearing
-prosthetic fitting not possible
3.Amputation thru the lower leg (IDEAL SHAPE for TRANSTIBIO-FIBULAR :
CYLINDRICAL)
a.thru the lower 3rd of the leg
- unsatisfactory adaptation of the stump to the prosthesis
c. amputation thru the middle third
-IDEAL LENGTH FOR TRANSTIBIO-FIBULAR AMPUTATION
-6 inches (5-7 inches) from the medial tibial plateau/tibial tubercle to the end of the stump
-quadriceps tends to weaken (vastus medialis) since hamstrings tend to pull stump into
flexion
4. Amputation thru the thigh ( IDEAL SHAPE for TRANSFEMORAL AMPUTATION:
CONICAL)
a. Grittie-Stokes amputation
-Similar to syme’s amputation (provides weight bearing and can withstand excessive strain)\
-Utilized sectioned patella fused to the femur at or about the level of the adductor
Tubercle
-osteoplasty which involdves disarticulation of the knee joint,then sawing off the
articular surface of the patella,the patella is approximated to the end of the
femur,created an end bearing stump
b. Ischial bearing amputation
-IDEAL TRANSFEMORAL AMPUTATION
_Ideal length:10-12 inches from the greater rochanter to the ned of the stump
-utilizes the power of adductur muscles
-iliopsoas (hip flexors) and gluteus medius (abductors) unaffected
-Gluetus maximus (hip extensors) and adductor magnus reduced in volume and power
5. Amputation thru the thigh above the ideal level
-the shorter the stump, the greater the difficulty in maintaining and activating the
prosthesis
-greater tendency for contractures
-when te stump is only 3-4 below ischial tuberosity and adductor tendon insertion,it is
it is impossible to retain the stump within the socket of the prosthesis
6.Amputaton about the hip
-amputation thru the trochanters,femoral neck and hip disarticulation
-needs to be fitted with a tilt table type of prosthesis
7.Hindquarter Amputation
-done only in cases where there is a malignant tumor
-removal of the pelvis by disarticulation of the symphysis pubis and section of the
posterior portion of the ilium near the SI jt (together with the severance of the soft
tissues connecting the trunk with the extremities)
8.Hemicorporectomy
-removal of the entire lower extremity through the last 2 lumbar vertebrae (L4-L5)
sacrum,coccyx,half of the pelvis
-Involves the creational of an artificial bladder and rectum


LEVELS OF AMPUTATION:
A.UE
-if unilateral
percentage from Normal
a.Transhumeral ---------------Classification
0=shoulder disarticulation
0-30 =humeral neck
30-50 =short transhumeral stump
50-90= long transhumeral stump,
elbow disarticulation
b.transradio-ulnar

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