Amputations

Amputations about the Knee

BKA / Below Knee Amputation / Transtibial

 

Best results

- long posterior musculocutaneous flap 

- well cushioned mobile muscle mass

- full thickness skin

- very anterior scar

 

Contraindication

- non-ambulator

- get FFD

- better with through knee amputation

 

Advantages over AKA 

 

1.  Good Healing 

- > 90% in DM with BKA

 

2.  Higher prosthesis wearing rates 

- 74% vs 26% for AKA

 

3.  Reduced energy required for walking

- 74% BKA < 45 year old walk > 1 mile

 

4.  Reduced mortality 

- 10% vs 30%

 

Technique 

 

Tourniquet

- no tourniquet if PVD

- tourniquet in trauma (patients can bleed to death)

 

Posterior flap

- mark long posterior flap

- avoid suture line over anterior aspect of tibia / problems frequent here

 

Anterior flap

- short anterior flap at level of tibia cut

- want to extend posterior flap over distal tibia

 

Anterior Dissection

- find anterior NV bundle between T anterior and EHL

- deep peroneal nerve on interossesous bundle

- divide anterolateral muscles at tibial level to avoid bulbous stump

 

Tibial resection

- 15cm stump from joint

- no advantage in > 15cm as skinny poor stump

- < 3cm stump worse than through knee

- sharp dissect periosteum 2 cm above

- leave periosteal flap so can suture muscle flap to it

- bevel sharp edges

 

Fibula resection

- divide fibula 2cm above this

- need to ensure is stable (well connected to tibia via interosseous membrane)

- if not may need to create arthrodesis in young active patient

 

Fibular arthrodesis / unstabile fibula

- create wedge in tibia

- elevate periosteal sleeve to place over top of graft

- use 1 cm of fibula

- can get pain for 6-9 months as the graft unites

 

Posterior dissection

- find posterior tibial artery and tibial nerve

- on tibialis posterior between FDL and FHL

- divide deep muscles and allow to retract

- remove soleus leaving only gastrocnemius flap

- ensure vascularity flap

 

Myodesis gastrocnemius

- through drill holes in tibia and to periosteum of tibia

- fascial repair over muscle bellies

 

Closure

- over drain

- DPC if trauma or infection

- careful pressure dressings with tape to ensure good shaping

 

Through Knee

 

Indications

 

1.  Non ambulators

- aids sitting balance

- avoids FFD and subsequent problems

 

2.  < 3-5 cm tibia

 

3.  ST tissue loss means BKA not possible

 

Advantage over AKA

- improved socket suspension

- longer lever arm 

- muscle balanced amputation

- end-bearing potential

- less volume changes

 

Disadvantage

- asymmetrical knee joint

- bulky prosthesis

- overcome by newer prosthetic techniques

 

Technique

 

Tourniquet 

- patients can bleed to death

 

Flaps

- equal anterior / posterior flaps

- 5cm distal to knee joint

- fish mouth

- can make posterior flap slightly longer

 

Patella 

- depends on technique 

- original method is to retain patella

- Mazet & Hennessy excise patella from tendon

 

Knee dissection

- divide PT off tibial tuberosity

- cruciates and collaterals divided at level of below meniscus

- aim to keep them long

- this preserves the rich proprioceptive function of the capsule

 

Deep dissection

- divide posterior capsule

- find and ligate popliteal artery and vein

- finding tibial nerve, tension, sharp divide, diathermy

 

Myodesis

- PT sutured to cruciate stumps

- biceps tendon sutured to PT

- gastrocnemius to anterior capsule

 

AKA / Transfemoral

 

Issues

- energy expenditure increased by 65%

- residual abduction as A Magnus released from adductor tubercle

- myodesis in 10o adduction maintains abductor strength and prevents abductor lurch

- residual flexion due to quads / hamstring inbalance

 

Technique

 

Position

- sandbag under buttock

- avoid having leg in flexed position

 

Tourniquet 

- if able 

- can bleed to death

 

Flaps

- actually want scar slightly posterior, with larger anterior muscle flap

- fish mouth

- larger anterior flap skin and muscle 

 

Dissection

- cut quadriceps tendon above patella

- detach sartorius / gracilis / hamstrings 2 cm longer for myodesis

- detach A Magnus

 

Vessels

- SFA below vas medialis in Hunter's canal / subsartorial canal

- profunda femoris posterior to femur

- can cut femur first to give access to NV bundles

 

Femoral transection

- save all possible femoral length

- increasing length increases muscle strength

- minimum 12 cm above knee to fit in prosthetic knee joint

- has to be >18 cm from GT or fixation difficult

- if stump < 5 cm below lesser trochanter then fitted as hip disarticulation

 

Adductor myodesis

- maintain stump in 10° adduction

- anatomical position

- suture through drill holes in lateral femoral cortex

 

Anterior musculature

- myodesis of quadriceps to posterior femur avoids FFD

- through anterior drill holes

 

Posterior musculature

- myoplasty to A Magnus or quads

 

Soft spica

- suspend dressing from waist

- support medial thigh

 

Post-op

- positioning important to prevent contractures

- stump flat on bed

- intermittent prone positioning

 

 

 

Foot and Ankle Amputations

Level

 

Level not predicated by angiography

- best is appearance of ST at time of surgery as judged by experienced surgeon

 

Toe

 

Technique

- dorsal-plantar or side-to-side flap

- tension free closure

- high reamputation rate in PVD / DM

 

Hallux

 

Technique

- stabilise sesamoids in hallux amputation

- leave base of P1 to prevent adjacent toes falling into gap

- this also preserves plantar fascia

- tenodesis of FHB

 

Second Toe

- beware of HV postoperatively

- can use insert

- may need to fuse 1st MTPJ

 

Ray 

 

Indications

- single medial or lateral ray that has an infected ulcer

- multiple resections may excessively narrow foot

- central ray amputations are inferior to Lis Franc amputation

 

Technique

- racquet shaped incision based on involved MT to avoid NV bundles

- most are partial ray resections

- leave base

 

Prosthesis

- Oxford extra-depth shoes with custom insoles

 

Lisfranc

 

Technique

- at TMT

- create long plantar flap

- smooth curve fashioned 

 

Precautions

- muscle balance

- Tendo achilles lengthening may be required to avoid later equinus

- muscle reattachment especially Peroneus brevis (try to preserve base fifth MT)

 

Prosthesis

- may initially require AFO

- usually shoe filler eventually

 

Chopart 

 

Concept

- excellent amputation

- through midfoot leaving only talus and calcaneum

 

Advantage over Symes

- no problems with heel pad migration

- functional end bearing stump

- no LLD

 

Technique

- original procedure without transfer had problems with late equinus & varus

- reattach to talus neck T. Ant / T Post / EHL / EDL

- Tendo achilles lengthening

 

Prosthesis

- AFO with foot plate & filler

- slipper style prosthesis

 

Boyd

 

Concept

- talectomy / forward shift of calcaneum / calcaneotibial arthrodesis

 

Advantage over Symes

- preserves length & growth centres

- no heel pad migration

 

Disadvantage

- bulky stump

- poorer cosmesis

 

Technique

- dorsal incision from tip LM to 1 inch below MM

- planter incision transversely across sole at level MT bases

- amputate forefoot through Chopart joint

- excise talus

- anterior calcaneal osteotomy transversely across calcaneum at level of peroneal tubercle

- shift calcaneum anteriorly

- excise cartilage of distal tibia / fibula & superior calcaneum

- calcaneo / tibial arthrodesis

- steinman pin through calcaneum and tibia 

- close over drains

 

Pirigoff 

 

Concept

- talectomy 

- anterior 1/2 calcaneum excised 

- rotated 90°

- calcaneo-tibial arthrodesis

- used in children to preserve length & growth centres

 

Symes

 

Principle

- through ankle joint

- may allow ambulation with out prosthesis in emergencies 

- end-bearing with stable gait pattern

- can still fit ankle prothesis

- women can be unhappy with cosmesis

 

Technique

- from tip of LM to 1 inch below tip MM across front of ankle

- then continue plantarward under sole between same points / MT bases

- need to preserve large post heel pad

- excise talus & calcaneus

- remove malleoli at level of joint & contour 

- divide arteries / veins / nerves above levels of flaps

- anchor heel pad to anterior tibia via intra-osseous sutures 

 

Problems

- heel pad migration is biggest complication

- don't trim dog ears or can get skin slough

 

 

 

 

 

 

Hip Amputation

Hip Disarticulation / Boyd Technique 

 

Anterior Racquet shaped incision

- begins just inferior to ASIS

- curves medially to under inguinal ligament

- 5 cm distal to adductor origin

 

Identify and ligate femoral artery and vein

 

Posterior incision

- 5 cm beneath ischial tuberosity

- laterally 8 cm below greater trochanter 

- then curve back to ASIS

 

Superficial Dissection

- detach sartorius & rectus femoris proximal

- divide pectineus 1/2 inch from the pubis

- avoid division of obturator vessels from where exit pelvis

 

Anterior Deep Dissection

- ER leg

- divide iliopsoas tendon at LT

- detach adductors & gracilis at ischium

- expose and ligate obturator artery / nerve between pectineus & obturator externus at femur

 

Posterior Deep Dissection

- IR leg

- divide obturator externus / short external rotators at femur

- detach G max & G med from femur

- divide G max in line of skin incision

 

Hip

- disarticulation

- divide capsule & L Teres

- divide hamstrings at ischium

 

Muscle flaps

- suture gluteal flap to pectineus & adductor muscles 

- approximate skin edges

 

Hindquarter Amputation

 

AKA

- hemipelvectomy

- trans-iliac /trans-pelvic amputation

 

Set Up

- two surgeons 

- colostomy & stitch anus closed

- eschmarc to express limb of blood to prevent shock

- cross match 3 L of blood

- prepped from chest to below knees

- tape scrotum to opposite leg

- special frame to hold leg 

- lateral with amputated limb up

 

3 Part Technique King & Steelquist

 

Anterior Part

- begin incision at pubic tubercle

- extend along inguinal ligament to ASIS

- extend along crest to PSIS 

- detach abdominal muscles & inguinal ligament from the crest 

- open iliac fossae between peritoneum & iliacus

- at the pubis severe the inguinal ligament & the rectus abdominis & retract the cord medially

- open the space of retzius & retract the bladder into the pelvis

- divide external iliac artery and vein & femoral nerve

 

Perineal Part

- widely abduct the leg

- extend the incision from the pubic tubercle, along the pubic & ischial rami to the ischial tuberosity

- expose the subcutaneous rami

- elevate the ischiocavernosus & transversus perinei subperiosteally from the rami inferior surfaces

- divide symphysis pubis with osteotome

 

Posterior Part

- carry incision from PSIS to GT then along gluteal crease to ischial tuberosity 

- expose G max aponeurosis in line with the skin incision 

- elevate G max, forming a large flap of skin, fat & muscle

- expose G medius & short rotators into view 

- sever piriformis & sciatic nerve

- pass gigli saw through greater sciatic notch & bring it out over iliac crest just anterior to SIJ

- divide ilium, sacrotuberous & sacrospinous ligaments

- rotate inominate bone with leg to expose pelvic contents

- divide obturator artery and vein

- divide psoas at SIJ

- divide levator ani off pelvic wall

- hemipelvis now free

 

Closure

- suture G max flap to rectus abdominus / lateral abdominal wall / quadratus lumborum / psoas

- close skin over drains

- firm dressing

 

 

 

 

LEAP Study

Lower Extremity Assessment Project

 

Set up

 

Multicentre Prospective Outcome Study

- 601 patients

- severe, limb threatening lower extremity injuries

- 8 level 1 trauma centres

 

Inclusions

 

IIIC / IIIB / selected IIIA

- knee dislocations or closed tibial fractures associated with vascular injuries

- major ST injuries

- severe foot / ankle injuries (open pilon, type IIIB ankle)

 

Exclusions

 

GCS < 15 day 21

Third degree burns

Spinal cord deficit

 

Sensate sole

 

Bosse et al JBJS Am Dec 2005

 

3 groups of patients

1.  26 patients with insensate sole at time of admission who underwent amputation

2.  29 patients with insensate sole at time of admission who underwent limb salvage

3.  Case matched group with sensate sole who underwent limb salvage

 

Assessed at 12 and 24 months

- orthopaedic surgeon

- occupational therapist

- VAS

- sensation assessed

 

Sensate v insensate salvage groups

- no difference late amputation

- no functional difference

- similar sensory examinations at 24 months

 

Insensate salvage v insensate amputation

- amputation more likely to use walking aid

- amputation more likely to have difficulty with stairs

 

Impression

- insensate sole is a poor predictor of eventual function and poor guide to amputation

- a large number have reversible ischaemia or neuropraxia

 

Outcomes of Reconstruction or Amputation

 

Bosse et al N Eng J Medicine Dec 2002

 

Case matched

- functional outcome for amputation or reconstruction the same

 

 

 

 

 

Mangled Extremity Severity Score

Mangled Extremity Severity Score  

 

Johansen et al 1990        

- no score is an absolute predictor of need for amputation

- only acts as a guide

- better to use in conjunction with vascular / soft tissue / bony reconstruction  required

 

"VISA gives you double frequent flyer points after 6 hours"

 

Velocity

Ischaemia

Shock

Age

 

Velocity

 

Low Energy           1

Medium Energy     2

High Energy          3

Very High Energy   4

 

Ischemia

 

Poor pulse                 1

Pulseless & poor CR   2

Totally avascular         3

 

Score doubled for ischemia > 6/24

 

Shock

 

Systolic BP > 90 mm Hg 0

Hypotensive transiently     1

Persistent hypotension      2

 

Age (Years)

 

< 30 0

30-50    1

> 50     2

 

Max = 11 or 14 if > 6hrs

 

>7 = 100% chance of amputation

 

Results

 

Helfet Clin Orthop 1990

- objective criteria can predict amputation after lower-extremity trauma

- MESS was prospectively evaluated in 26 lower-extremity open fractures with vascular injury

- 4.00 for the 14 salvaged limbs 

- 8.83 for the 12 amputated limbs p < 0.01

- MESS > 7 100% predictive value for amputation

 

 

 

 

Principles

Epidemiology

 

2/3 PVD 

1/3 Trauma 

5% Tumour

1% Congenital

 

Indications

 

Dead / Dying / Dangerous / Damn nuisance

 

Indications for amputation in open tibial fracture

 

Lange et al J Trauma 1985

 

Absolute Indications (1 of 2)

1.  Complete tibial nerve disruption

2.  Crush injury with warm ischaemia time > 6 hours

 

Relative indications (2 of 3)

- serious associated polytrauma

- severe ipsilateral foot trauma

- projected long course to full recovery

 

MESS (Mangled Extremity Severity Score) guide only

- involve patient in decision

 

Aims

 

Aim

- maximum function

- minimum complication rate

 

Ambulatory

- most distal level that will achieve healing & provide functional stump

 

Non-ambulatory

- improve sitting balance, transfers & nursing care

- through knee best in non ambulatory

- balanced amputation

- no FFD of knee, which limits impinging on bed and development of sores

 

Principles of Good Outcome

 

1.  Reconstructive approach 

- not considered as a failure

2.  Team approach

- early involvement of rehab / prosthetist

3.  Pre-op assessment & planning

4.  Patient explanation & involvement

5.  Good surgical technique

- optimal limb length

- good residual joint

- excellent ST (non adherent and durable) with muscle cushioning

6.  Early prosthetic fitting

7.  Amputee rehabilitation

8.  Appropriate prosthesis prescription

 

Energy Cost of Level

 

O2 Consumption inversely proportional to

- length of residual limb

- number of joints preserved

 

Increase over baseline

- long BKA 10%

- medium BKA 20%

- short BKA 40%

- medium AKA 60%

- hindquarter 100% +

- wheelchair ~ 0%

 

Maximum walking speeds

- normal = 82 m /min

- BKA = 50-70 m /min

- AKA = 40-55 m /min

 

Geriatric with PVD & AKA is virtually at maximum energy expenditure

 

End Bearing Vs Non- End Bearing

 

End Bearing / disarticulation 

 

Weight taken through end of stump

- scar non-terminal

- bone end metaphyseal, not hollow diaphyseal

- usually joint disarticulation

- end bearing prosthesis used

 

Non End Bearing / transosseous

 

Commonest

- intimate fit needed to distribute load over as wide a load as possible

- load transfer usually over the entire residual limb

- scar can be terminal

- usually trans-osseous amputations where end bearing would be too painful

 

Surgery

 

Planning

 

Maximise length & joints

Vascularity

Skin cover

Infection

Prosthetic

 

Skin Flaps

- careful planning

- Atraumatic ST handling

- keep skin flaps thick

- avoid unnecessary dissection between tissue planes

- Non-terminal if end bearing

- Terminal if °End bearing

- Full thickness skin 

- Avoid SSG

 

Bone

- leave long

- Bevelled bone end

- Min Periosteal strip in adults

- strip 0.5 cm in kids to prevent terminal overgrowth

 

Muscles

 

Aim

- Mobile non-adherent muscle mass

 

Stabilisation of distal ends

- provides padding over bone

- prevents atrophy

- avoids FFD by balancing deforming forces

- improves lever arm length i.e. avoid trendelenberg in AKA

 

Techniques

- suture at functional length

- Myodesis - suture to bone

- Myoplasty - suture to muscle or ST

 

Nerve

- Sharp division of nerve under gentle non-crushing retraction

- Allows cut end to retract into ST

- inevitable neuroma cushioned by muscle

- Clamping increases CRPS II

- Ligature / Diathermy has no effect

 

Closure

- Excellent haemostasis

- Delayed closure as needed

 

IPSF vs EPSF

 

Immediate Post surgical Prosthesis Limb Fitting IPSF

- Rapid application of limb < 5/7

- Early Weight bearing

- Suitable for traumatic amputee's 

- Increased wound complications due to rapid stump shrinkage in first 2weeks

 

Early Post surgical Prosthesis Limb Fitting

- Better as most rapid stump shrinkage has occurred 

- 14-21 days

- Less wound complications

 

Complications

 

Pain

 

1. Phantom Sensation

- Sensation that limb still present

- Occurs in most patients

- Usually diminishes over time

 

2. Phantom Pain

 

Burning pain in Phantom limb

- Occurs in ~10% of pts

- usually settles 4- 6 weeks

 

Treatment

- Increase prosthetic use

- Physio

- TENS

 

3.  Causalgia / RSD 

 

Pain in stum - Burning / throbbing etc

 

Non-op Treatment

- Massage, Compression, TENS

- Varied success

 

Operative Treatment

- Limited success

 

Prevention

- Effective

- Peri-op Epidural

- Post-op intraneural anaesthesia

 

4. Mechanical Causes 

- Sharp bone end

- Poor ST envelope

- Unstable skin 

- Ill fitting prosthesis

 

5. Other Causes

- Radicular pain

- Proximal OA

- Ischaemic pain

- Neuroma not uncommon cause consider LA injection for Dx

 

Oedema 

 

Common

- Minimise with rigid dressings

- If soft dressings used, stump wrapping important

 

Excessive proximal tightness results in

- Proximal narrowing

- Increased distal oedema

- Dumb Bell stump

 

Contractures 

 

Usually occur between amputation & prosthetic fitting

 

Hip In AKA

 

Deformities

- FFD

- abduction

 

Minimised by

- Adductor Magnus / Hamstring stabilisation 

- Quads myodesis to posterior femur

- Avoidance of stump on pillow

- Early active & passive exercises

- Prone lying

 

Knee in BKA

 

Deformity

- FFD

 

Minimised by

- LL rigid dressings

- EPLF

- Quads strengthening

- HS stretching

- Difficult to treat once established because of short lever arm

 

Wound 

 

Breakdown not uncommon

- Especially in PVD & DM

 

Dermatological 

 

Numerous problems

- Epidermoid cysts

- Contact dermatitis

- Superficial skin infections

 

 

 

Prosthetics

Contraindications

 

No ambulation potential

Severe cardiac disease 

Poor vision

Poor motivation or compliance

Poor stump - infected, ulceration, poor skin

FFD knee or hip

 

Indications

 

Young traumatic or neoplastic amputee

Motivated PVD / neuropathy amputee with cardiac reserves

 

Timing

 

Best to fit prothesis ~ day 14 

- allows most stump shrinkage to occur

- IPOP tends to cause high complication rate especially with PVD

 

Elements of a Prosthesis

 

1. Socket

- transmits forces between the stump & the prosthesis in all planes 

- may be proximal, distal or total bearing 

 

2. Means of Suspension

- suction socket 

- suspension belts 

- neoprene sleeve 

- elastic stocking 

- silicone sleeve 

 

3. Joint mechanism (knee)

 

A.  Stance phase control 

 

Simple 

- aligns the prosthesis so the ground reaction force passes in front of the knee 

- locks in hyperextension; 2 drums lock at 0-15o

- for elderly 

 

Mechanical stabilisers 

- braking mechanism activated by the weight bearing load or hydraulics

 

B.  Swing phase control 

- pneumatic cylinder 

- hydraulic cylinder 

- intelligent prosthesis - computer adjusts rate of swing to cadence (steps/min) 

 

4. Terminal device / Foot 

 

A.  SACH 

- Solid Ankle Cushioned Heel

- wood keel / heel cushion / rubber foot

- use for BKA

 

B.  Single axis

- some DF/ PF possible

- makes knee stable

- use if knee stiff ie AKA or through knee

 

C.   Multi - Axis Foot

- hindfoot eversion / inversion + DF / PF

- better for active patient

 

D.   Dynamic Response

- "Ryan's Superfoot"

- flexible keel allows smoother roll over

- store energy via carbon fibre foot plate

- Aid toe off / more natural gait / save energy

- expensive

- not used in children as turnover too high

 

BKA Prosthesis

 

Socket

 

Usually firm PTB design

- can add liner for increased comfort

- definitive socket fitted 1 year (size stabilised by then)

- load patella tendon & medial / lateral flares

- most weight actually borne on medial tibial flare

- extend flares higher if unstable knee

 

Suspension 

 

Suprapatellar cuff

- simplest & most common

- dacron & leather

- grips condyles

- advantage is transfers all force to residual leg below knee

 

Supracondylar mould

- grips above femoral condyles

- young patient or < 5cm residual tibia

 

Neoprene 5mm liner

- rolled over distal thigh

- frictional fit ± suction

- negative pressures in swing

 

AKA Prosthesis 

 

Suspension

 

Difficult

- lack of bony contours

- not truly end bearing

- usually ischial bearing

 

Options

1. Suction with valve hole

2. Waist or hip belts - if femur too short

 

Requires

- surface tension

- negative pressure

- active muscles

- stable body weight / socket fits

 

Socket 

 

1. Quadrilateral

- traditional socket with narrow AP diameter

- weight bear on ischium / not in socket

- difficult for the femur to sit in adduction

 

2. CAT - CAM

- narrow medial - lateral diameter

- femur sits in adduction 

- more ovoid

- incorporate ischium into socket via flare

- more comfortable

- better femoral stability in socket

 

Knee Design Options

 

1. Single axis

- simple hinge

 

2.  Polycentric axis 

- 4 bar linkage device

- more natural

- expensive and heavy

 

3. Friction

- limits knee flexion

 

A.  Constant

- cheaper

- limited to one walking speed

 

B.  Variable friction, including with extension

- hydraulic controlled

- resist flexion in extended knee

- easy flexion in flexed knee

- allows different speeds 

 

4.  Safety knees / Stance control knee

- lock when weight applied 

- good for elderly

 

Commonest

- Single Axis Safety Knee

 

Most expensive & heaviest

- Polycentric Hydraulic Controlled Knee

 

Through Knee Prosthesis

 

Socket

- endbearing socket

 

Suspension 

- via femoral condyle flares or strap

- 4 bar linkage knee overcomes previous problems with through knee

- folds away when sitting

- knees at same level

 

 

Upper Limb Amputations

General Principles

 

All possible length should be preserved consistent with clinical judgement

- function of amputated stumps decrease progressively with each higher level of amputation 

- prosthetic rejection by patient increases with the more proximal amputations

- most ADL'S can be performed adequately with one limb, so don't use prosthesis

- all nerves are drawn distally into wound & sectioned so they retract well proximally to bone level of amputation

 

Transcarpal

 

Concept

- can preserve flexion / extension of radiocarpal joint which transmitted partly to prosthesis

 

Technique

- fashion long palmar, short dorsal flaps in ratio (2:1)

- divide tendons under tension

- divide nerves well proximal to amputation

- divide vessels just proximal to amputation bony level

- divide bones and smooth / round edges

- anchor wrist flexor and extensor tendons to remaining carpal bones in line of pull to allow wrist flexion/extension

 

Wrist disarticulation

 

Technique

- fashion long palmar, short dorsal flaps (2:1)

- skin apices 1cm distal to ulnar and radial styloids

- divide vessels, nerves, tendons and open radiocarpal joint

- resect radial / ulnar styloid processes & smoothen bony processes to form a smooth rounded contour

- protect distal radioulnar joint including triangular ligament to preserve supination/ pronation

- insert suction drain and skin closure 

 

Forearm

 

Forearm amputationForearm amputation

 

Concept

- preserve as much length as possible (forearm rotation and strength proportional to length retained)

- if circulation compromised, amputation through distal 1/3 forearm are less likely to heal

- distally skin is thin and subcutaneous tissue scant

- junction mid and distal thirds good compromise for amputation level

- short 'below elbow stump' (up to 3.8-5cm long) preferable to through or above elbow

- important to preserve elbow joint

 

Distal

- skin incision apices at level of bone cut

- ligate radial / ulnar arteries and divide nerves under tension then transverse bone cuts and rasp edges

- fashion FDS flap long enough to be carried around bone ends 

- section rest of muscles at level of bone

- suture FDS flap over dorsal fascia

 

Proximal third

- fashion equal volar and dorsal flaps ideally

- divide muscle bellies distal to bone cuts to allow for retraction

- transverse bone cuts and rasp edges

- if stump is proximal to bicipital radial tuberosity, then resect distal 2.5cm of biceps tendon

- this lengthens stump functionally and enhances prosthetic fitting

- leaves brachialis as principle elbow flexor

 

Krukenburg's Amputation

- performed as a secondary procedure in 'below elbow' amputation

- converts forearm amputation into radial and ulnar pincers

- need at least 10 cm from olecranon tip & elbow flexion contracture <70o

- classically used in blind bilateral below elbow amputee

 

Elbow disarticulation

 

Concept

- good level for amputation due to easy fitting of prosthesis to distal humeral flare

- allows transmission of humeral rotation to the prosthesis (preferable to a more proximal humeral amputation)

- due to modern prosthesis techniques, disarticulation is preferred to proximal humeral amputation

 

Technique

- equal anterior and posterior flaps with apices at level  of humeral epicondyles

- posterior flap extents 2.5cm. distal to olecranon tip

- anterior flap extends just distal to biceps tendon insertion

- divide lacertus fibrosis

- reflect distally flexor origin off medial epicondyle

- expose neurovascular bundle on medial side of biceps tendon

- divide brachial artery, median and ulnar nerves proximal to elbow joint

- free the insertions of biceps and brachialis from radius / ulna

- divide radial nerve as lies between brachialis and BR

- divide transversely extensor mass 6 cm distal to joint line

- divide posterior fascia and triceps tendon near tip of olecranon

- divide anterior joint capsule to complete the disarticulation & remove the forearm

- leave intact articular cartilage of humerus 

- suture triceps tendon anteriorly to biceps and brachialis

- suture extensor muscle mass medially to flexor origin muscle stump

 

Can add distal humeral osteotomy

- create anterior angulation 45o

- aids prosthesis fitting / reduces need for shoulder harness

 

Above Elbow

 

Concepts

- most important to preserve limb length

 

Above elbow prosthesis

- elbow-lock mechanism stabilises joint in full extension, flexion or in a position between

- lock mechanism extends 3.8 cm distally from the end of the prosthetic socket

- therefore most distal bone section should be 3.8cm from end of humerus to allow room for this mechanism

 

Supracondylar level

- equal anterior and posterior flaps at length 1/2 diameter of arm at that level

- artery and nerve divided proximal to level of resection

- divide anterior compartment muscle flaps 1.3cm distal to bone section level so they retract to this level

- free triceps insertion off olecranon & preserve as a long flap

- transverse bone cut 3.8 cm proximal to humerus end and rasp edges

- suture long flap of triceps anteriorly to the fascia over anterior muscles

 

Proximal to supracondylar level

- equal anterior and posterior flaps

- divide anterior compartment muscles 1cm distal to bone cut to allow retraction

- divide triceps 3.8-5cm distal to bone cut

- suture triceps anteriorly over bone end to anterior muscle fascia

 

Shoulder amputations

 

Concept

- shoulder amputation levels require fitting as if for joint disarticulation

- Prosthetic function is severely impaired at shoulder level 

- prostheses are used primarily as a holding device when performing activities with both hands

 

Through surgical neck

 

Position

- patient supine with sandbag beneath shoulder (patient's back 45 degrees to table)

 

Anterior incision

- incision from coracoid process, along anterior deltoid border to its insertion

 

Posterior incision

- along posterior deltoid border to posterior axillary fold

- connect the two limbs of incision by a second incision that passes through axilla then incise anteriorly through axilla

 

Superficial dissection

- ligate cephalic vein, separate deltoid and pectoralis major in deltopectoral groove

- reflect deltoid laterally

- divide pectoralis tendon at its insertion and reflect medially

 

Expose neurovascular bundle

- develop plane between pectoralis minor and coracobrachialis to expose neurovascular bundle

- divide axillary artery and vein inferior to pectoralis minor

- divide nerves on stretch so they retract proximal to pectoralis minor

 

Deep dissection

- divide deltoid insertion and reflect deltoid / lateral skin flap superiorly

- divide teres major and latissimus dorsi at bicipital groove

- divide short and long heads of biceps, triceps and coracobrachialis 2 cm distal to bone cut

- section bone at surgical NOH

 

Closure

- suture long head triceps, both heads biceps and coracobrachialis over end of humerus

- suture pectoralis major tendon to bone end

- bevel deltoid to allow skin closure

 

Shoulder disarticulation

 

Position and incision

- as above

 

Superficial dissection

- ligate cephalic vein

- separate deltoid and pectoralis major

- retract deltoid laterally and divide insertion

- divide pectoralis major tendon at insertion and reflect medially

 

Neurovascular bundle

- divide conjoint tendon and P minor on coracoid

- expose neurovascular bundle

- ligate axillary artery and vein and thoracoacromial artery

- divide nerves on stretch so they retract proximal to pectoralis minor

 

Deep dissection

- reflect deltoid insertion superiorly to expose shoulder joint capsule

- divide teres major and latissimus dorsi at insertions

- after internally rotating arm divide posterior rotator muscles at insertion & posterior capsule 

- place arm in extreme external rotation & divide subscapularis anterior joint capsule

- divide triceps at infraglenoid tubercle insertion & divide inferior capsule to severe the limb

 

Closure

- suture all muscles across glenoid to fill the hollow out (deltoid to inferior glenoid)

- may need to trim prominent anterior acromion to produce smoothly rounded contour

- drain deep to deltoid

 

Forequarter

 

Concept

- shoulder girdle amputation

- consists of removal entire shoulder girdle / upper limb in interval between scapula and thoracic wall

- indicated for malignant tumour involving upper humerus or shoulder joint

- atypical skin flaps often used, may require axillary skin grafts

 

Anterior Approach

 

Incision

 

Upper limb of incision

- begins at lateral border sternocleidomastoid

- extends laterally along anterior aspect clavicle

- back across AC joint

- over superior aspect shoulder to scapular spine

- inferiorly along vertebral border of scapula to inferior angle

 

Lower limb

- starts at mid 1/3 clavicle

- runs inferiorly in deltopectoral groove 

- runs posteriorly through axilla to join upper limb incision at inferior scapular angle

 

Superficial Dissection

- subperiosteally dissect out clavicle 

- cut at lateral border sternocleidomastoid and through AC joint

- external jugular divided or retracted

 

Deep Dissection

- release pectoralis major off humerus and pectoralis minor off coracoid to expose neurovascular structures

- ligate subclavian artery and vein, divide brachial plexus under stretch

- release Lat dorsi & remaining soft tissues that bind shoulder girdle to anterior chest wall and allow limb to fall posteriorly and down 

- while holding arm across the chest divide posterior rotator cuff

- divide anterior and posterior muscles holding scapula to thoracic wall 

- trapezius / omohyoid / L scapulae / rhomboids / serratus anterior 

- suture pectoralis major and trapezius over lateral chest wall

- trim flaps and primary suture

 

Posterior Approach

 

Position

- lateral decubitus position near edge of operation table

 

Incisions

 

Posterior

- make posterior incision first

- begin at medial end of clavicle, extending laterally along clavicle over acromion process to posterior axillary fold

- along axillary border of scapula to a point inferior to scapular angle

- curve incision medially to end 5cm from midline of the back

- same incision as for anterior approach except posterior limb runs along axillary border of scapula

 

Anterior

- as above

- starts at mid 1/3 clavicle and runs inferiorly just lateral and parallel to deltopectoral groove

- then runs posteriorly through axilla to join posterior axillary incision at lower 1/3 of axillary border of scapula

 

Superficial Dissection

- elevate full-thickness skin flaps and subcutaneous tissue to medial border of scapula

- trapezius / lat dorsi divided parallel to medial border of scapula

- divide Levator scap / rhomboids / serratus anterior / omohyoid from scapula

- ligate vessels especially transverse Cervical artery and Transverse scapular artery

- free clavicle and divide at medial end with subclavius

- shoulder falls anteriorly

 

Deep dissection

- subclavian artery & vein / brachial plexus on stretch (divided close to spine)

- divide P major and minor & remove limb