Amputaion

Definition:

A procedure which removes a part through one or more bones as apposed to disarticulation

Indications:

Dead, Dangerous, or a Damn nuisance limbs

Goals:

Ablation of diseased tissue
Reconstruction:
optimise pt function and reduce morbidity
to produce a physiological end organ

Epidemiology

85% ar lower limbs
R=L
75% in men

Aetiology

PVD
Diabetes
Trauma NB MESS
Nerve injury trophic ulceration
useless limb eg brachial plexus injury
Tumour
Congenital
Infection

Acute
eg gangrene

Chronic
eg failure to heal in a pyogenic infection
carcinoma in a chronic sinus
TB

Burns

Preop Evaluation

Tissue

Clinical - feel pulses, skin temperature, level of dependent rubor
Doppler - Ankle/ Brachial index more than .45 = 90% healing
inaccurate with calcified vessels
Toe systolic BP - 55 mm Hg min for distal healing
Transcutaneous PO2 min 35 for assured healing
Arteriogram
Other:
Skin blood flow (Xe 133 clearance)
thermography
thallium scanning

Immune Competence

serum albumin at least 3g/dl
WCC more than 1500/ mL

Systemic

control diabetes
evaluate cardiac, renal + cerebral circulation
Preop TPN in malnourished pt

Psychological

early plan for return to function
preop counselling
amputee support groups

Preop Pain Control

Pain clinic review
Spinal anaesthesia

Principles:

Tourniquet (except in PVD)

Skin flaps

Use defined flaps electively with the apex of the fish mouth at the level of the bony resection
Use any available flaps in trauma to preserve length
Tailor flaps at least as long as the diam of the stump

Options
Equal ant + post
Equal med + lat (Scandinavian for PVD esp)
Long post - PVD

Muscles

Divide ~5 cm distal to level of bone resection
Bevelling or contouring may be required for good stump shape
Stabilisation of muscle mass

provides stump padding
prevents atrophy
counterbalances deforming forces
improves function
prevents bursa formation

Myoplasty

involves suture of flexors to the extensors over bony stump

Myodesis

direct suture of muscle to bone - most useful in AK, AE and disarticulations

Nerves

Divide cleanly under gentle tension proximal to bone ends - allow to retract
No advantage for any particular technique of division
Large nerves eg sciatic - ligate due to large contained vessels

Vessels

Large arteries & veins should be doubly ligated and haemostasis achieved prior to closure

Bone

Avoid excessive periosteal stripping (prevent spur formation)
Chamfer appropriately

Closure

Do not close under tension
interrupted sutures

Drains

are necessary
In children:
Preserve length, disarticulate if possible to preserve growth potential rather than trans diaphyseal amputation

After care

Strapping (soft dressing or rigid POP)
Supervise closely until wounds healed

Soft dressings

Wrapping of stump vital
Crutches when limb control achieved
Air bag at wound healing
Definitive prosthesis at ~ 3 wks when stump stabilised

Timing of Prosthetic Fitting

Options

Immediate
Prompt - ~7-10 days when evidence of stump healing
Early - ~ 3 wks after stump has healed
Late - after stump is fully mature and little chance of stump breakdown

Prevent contracture

prone lying
muscle setting exercises
avoid hanging over bed, resting on crutch

Amputation levels

the most distal level that will heal and provide a functional stump

AKA
ideally bw 12 cm above knee and 18 cm below gt trochanter

BKA
ideal level at musculotendinous junction of gastroc
rule of thumb - allow 2.5 cm for every 30 cm of ht
ideal length - ~ 15 cm below med tibial artic surface
stumps less than 12 cm less efficient, those less than 6 cm do not function as BK stumps at all

AEA
20 cm from acromion

BEA
18 cm from tip of olecranon

Utilisation rates

90% BKA will use prosthesis
25% AKA will use prosthesis
75% of bilat BKA will ambulate
less than 25% of BK/AK will ambulate

Energy Expenditure

Depends on
amputation level
aetiology leading to amputation
aerobic capacity and cardiopulmonary efficiency
speed of gait - walking speed decreases with more prox amputation

Long BKA
10%
beyond baseline
Medium BKA
25%
Short BKA
40%
Average AKA
65%
Hip disarticulation
100%+


Complications:

Early

Wound
Haematoma

Flap
breakdown
Infection (especially in diabetics)
- Clostridial infection secondary to perineal contamination

Joint
contracture

Pain
wound pain
phantom sensation
phantom pain

Late

Joint
contracture
instability

Pain
due to pressure of ill fitting socket
phantom pain
neuroma

Stump
oedema due to prox venous constriction
unstable - too much soft tissue left
failure to perform myodesis

Skin
Verrucous hyperplasia
skin maceration
fungal infection / intertrigo
blisters
abrasion
atrophy
callosities
follicular hyperkeratosis
sycosis barbae
allergic reactions to material of cup or liner

Bone
spur formation - due to periosteal bone formation - avoid periosteal stripping osteoporosis
fracture

Cosmesis
sitting assymetry
bulbous stump eg Symes in females
severely scarred stump


Foot Amputations

The higher the amputation the greater the energy expenditure during walking

Toe Amputations:

Little disability unless the great toe
Use a longer plantar flap with the lateral apices at the level of the bone resection
In the great toe suture tendons over the stump in order to maintain the relationship of the sesamoids under the metatarsal head

Tarso-metatarsal:

Use long plantar and shorter dorsal flaps with the medial end being longer still
Requires a shoe filler ® near normal gait

Mid foot amputations:

Lisfranc
Through tarso-metatarsal joints

Choparts
Through mid tarsal joints and results in equino-varus deformity of the foot due to unbalance tendon pull

Pirogoffs
Calcaneum osteotomised, rotated and arthrodesis performed with the distal tibia. Talus excised

Syme's

James Syme 1799-1870 (Professor of Surgery Edinbough)
Amputation introduced in 1844 as an alternative to BKA
Lister was his assistant and married his daughter.

Operative Technique

Skin incision from tip of malleoli across anterior angle of the ankle crease and vertically distally
Sub periosteal dissection of calcaneus
Distal tibia and fibula resected 5mm from joint
Plantar aponeurosis attached to bone and skin flaps closed

Boyd

Talectomy with the calcaneum arthrodesed to the distal tibia (Avoids the problems of migration of the heal pad).


Below Knee Amputation

A stump less than 6cm in length is not functional
Skin flaps should be 1/2 the AP diameter of the limb in length and medial and lateral apices should be at the level of bony resection

Operative Technique

Tourniquet (if not PVD)
Mark level of bony resection and measure AP diameter
Mark anterior and posterior flaps (1/2 AP diameter)
Divide skin, subcutaneous fat and fascia in the same line as with the periosteum of the antero-medial surface of the tibia
Elevate flaps to the level of the amputation
Identify superficial peroneal nerve between EDL and peroneus brevis, pull distally and divide
Divide anterior tibial vessels and deep peroneal nerve
Section anterior muscles 0.75cm distal the bony resection
Bevel tibia at level of resection prior to division of the bone (easier)
Section fibula 3cm proximal to tibia (? excise it in young people)
Divide posterior vessels and nerve
Fashion posterior flap and aponeurosis of gastrocnemius to meet anterior muscles
Release tourniquet and obtain haemostasis
Close wound in layers (fascia, fat and skin), drain and apply a stump bandage


Through Knee Amputation

ref: Rogers "Amputation at the Knee Jt" JBJS 22: 973, 1940

Advantages:

large end bearing surfaces of distal femur are preserved
long lever arm controlled by strong muscles is created
the prosthesis used on the stump is stable

Technique:


ref: Batch etal "Advantages of the knee disarticulation over amputations through the thigh"
JBJS 36A: 921, 1954

Longer ant flap ( ~10 cm), shorter post flap ( ~5 cm), lat edge of flaps at level of the tibial condyles
Ant flap includes insertion of the patellar tenson and the pes anserinus, reflect these up and expose the knee, dissecting ant capsule from the ant, lat + med margins of the tibia
Divide the cruciates from the tibia and dissect the post capsule from the post tibia
Identify tibial n., gently pull distally + transect to allow it to retract well proximal
Ligate ( double) the popliteal artery + divide
Free biceps tendon from the fibula and complete the amputation posteriorly
DO NOT excise patella or attempt to fuse it to the femoral condyles
disturb the artic cartilage of the distal femur
Closure
Suture patellar tendon to the cruciate ligs and the remnant of gastrocs to tissue in the intercondylar notch
Close deep fascia with absorbable sutures and skin with interrupted nonabsorbable sutures
use a wound drain

Pointers:

if sufficient skin is not available for closure - can resect post condyles
if wound fails to heal primarily - usually granulates without further surgery


Above Knee Amputation

Operative Technique

Mark level of bony resection
ideal is between 12 cm above knee joint and 18cm below greater trochanter
less than 5 cm distal to lesser troch function as and are prosthetically fitted as a hip disarticulation
Apex of incision at the level of the bony resection
Ant flap 2.5cm longer than post flap
Subcutaneous tissue and fascia divided in line with the skin and reflected proximally
Femoral vessels and nerve identified deep to sartorius
Posteriorly sciatic nerve identified deep to hamstrings on adductor magnus
Divide deep femoral vessels
Divide quads bevelled upwards from underneath to level of bony resection
Divide bone + bevel with rasp
Prominence of linea aspira excised
Tourniquet released and haemostasis achieved
Muscle flaps approximated (myoplasty) - through small drill holes attach adductor and hamstring muscles to the bone. Then bring the Quads over the post end of the bone, suturing its fascia to the post fascia of the thigh
Drains inserted and wound closed with interrupted sutures
Stump bandage


Hip Disarticulation

ref : Boyd "Anatomic Disarticulation of the Hip" Surg Gynaecol Obstet 84: 346, 1947

Operative Technique

Anterior racket incision starting at the ASIS ® 5cm distal to adductor origin and ischial tuberosity and 8cm distal to greater trochanter
Identify femoral neurovascular bundle and ligate
detach and reflect sartorius and rectus femoris from ilium
Divide pectineus 6mm from its origin
Externally rotate the thigh and divide ilio-psoas
Detach adductor longus , gracillus and adductor magnus origins from pubis + ischium
Identify obturator artery between pectineus and obturator externus + ligate/ divide
Internally rotate the thigh: divide gluteus medius + minimus from the gt trochanter
Divide fascia lata (and hence tensor fascia lata) in line with skin incision
Separate gluteus maximus from linea aspira
Identify, ligate and divide the sciatic nerve
Divide
external rotators from femur
hamstrings from their origin
Divide capsule and ligamentum teres to complete the amputation
Suture glutei muscles and tensor to remnant of pectineus
Close skin over drains


Hindquarter Amputation

ref: King and Steelquist "Transiliac amputation" JBJS 25: 351, 1943

Operative Technique

Attention to perineal hygiene:
bowel prep with enemas
insert urinary catheter
anus stitched closed or sealed off with adhesive drape

Anterior Part

Incision from pubic tubercle along inguinal ligament over iliac crest to level of iliac resection, turn inferiorly and forward around the greater trochanter then posteriorly and medially around the gluteal fold.
Detach abdomial muscles and inguinal lig from the iliac crest + open the iliac fossa bw peritoneum and iliacus. At pubis sever the inguinal lig and tendon of rectus abdominis
Spermatic cord and abdominal contents retracted medially
Ligate external iliac artery + vein. If posterior incision includes gluteus maximus save the hypogastric artery

Perineal Part

Abduct leg, expose the rami, subperiosteally remove the Ischiocavernosus and transversus perinei. Divide symphysis

Posterior Part

Expose the post and inferior edges of G. max, divide its aponeurosis in line with skin, reflect it proximally to expose G. medius + minimus.
Divide Pyriformis and ligate the sciatic nerve
Pass a Gigli saw around the greater sciatic notch - section the ilium at the desired position - this mobilises the innominate bone - rotate it externally for wider intrapelvic exposure
ligate and divide obturator vessels and nerves and divide the psoas at the level of the SI jt
Divide levator ani from its pubic origin - this frees the entire extremity
Bring G. max flap anteriorly and suture it to the rectus abdominis, lat abdominal,
Q lumborum and psoas muscles
Close skin flap over drains


Upper Limb Amputation

Trans carpal Disarticulation

Results in limited pronation and supination, flexion and extension preserved.
Use a long palmar and short dorsal fish mouth flap (2:1)
Suture tendons over the ends of the carpus

Wrist Disarticulation

Fish mouth starts 1.3cm proximal to radial styloid
Resect radial and ulna styloids' without damage to distal radio-ulna joint and triangular fibro- cartilage.
Tendons are divided and allowed to retract.
Retains some pronation and supination therefore preferred to BEA

Below Elbow Amputation

Fish mouth equal anterior and posterior flaps about 1/2 the diameter of the arm at the level of the amputation.
Divide nerves under tension and divide muscles at the level of the intended bony resection.
Myoplastic closure suturing FDS to the extensor group.

Through Elbow Amputation

Use equal anterior and posterior flaps with the apices at the level of the humeral condyles and flap extending 2.5cm distal to the olecranon posteriorly and to level of insertion of biceps tendon anteriorly.
Free muscle attachments to medial and lateral condyles
Ligate nerves under tension
Leave the articular surface intact and suture triceps tendon to brachialis, and remnant of flexors to extensors.
Close flaps over drains

AEA

Use equal anterior and posterior flaps.
Divide flexors 1.3cm below the level of bony resection, and the triceps 4cm below the bony resection.
Suture triceps to anterior fascia.

Krunkenbergs' Operation

Separate radial and ulna rays distally ® radial and ulna pincers capable of strong prehension and excellent manipulative ability.
Especially useful for blind patients with bilateral BEA's but may be of some use in other amputees as well.

Shoulder Disarticulation & Amputation Through Surgical Neck

Operative Technique

Racquet incision from tip of coracoid, along ant deltoid ,over deltoid insertion laterally, along post deltoid to post axillary fold, then back across the axilla to the ant side
Ligate cephalic vein
Reflect pectoralis major off its insertion
Locate neurovascular structures in interval between coracobrachialis and pectoralis minor
Ligate axillary artery and divide nerves under gentle tension allowing them to retract
Reflect deltoid off its insertion and divide latisimus dorsi and teres major near the bicipital groove
Divide biceps and triceps tendons 2cm distal to the level of bony resection (at origin of disarticulation)
For proximal amputation
-Resect bone at desired level - then suture the LHT, LHB + SHB, and coracobrachialis over the end of the humerus and swing pec major laterally and suture to the end of the bone

For disarticulation
-divide capsule and rotator cuff
- then reflect the cut ends of all the muscles over the glenoid and suture them there - and secure muscle ends over the glenoid cavity
- then bring the deltoid flap inferiorly and suture just inferior to the glenoid
- Trim coracoid if too prominent
Close skin over drains


Fore Quarter Amputation

is the removal of the upper limb in the interval bw the scapula and the chest wall
ref: Littlewood " Amputations at the shoulder and the hip" Br Med J 1: 381, 1922

Operative Technique

Posterior incision from medial end of clavicle ,along clavicle over acromion and down lateral border of scapula, ending ~ 5 cm from midline at back.
Anterior incision from mid clavicle, curving down just lat and parallel with the deltopectoral groove, down over ant axillary fold inferiorly and posteriorly to meet the posterior incision at the lower 1/3 of the axillary border of the scapula
Develop the posterior flap to expose the vertebral border of the scapula and divide trapezius, rhomboids, levator scapulae and latisimus dorsi from the scapula
Reflect scapula to divide attachment of serratus anterior and omo-hyoid
Allow arm to drop forward ® plexus under tension and divide cords of the brachial plexus near the spine
Double ligation of subclavian artery and vein
From the anterior incision divide clavicle near medial end
Divide pectoralis muscles and insertion of latisimus dorsi to complete the resection
Perform a myoplastic closure and close skin over drains.