amputation

Amputation: is the 1st step of rehabilitation.
Indications:
Dead or dying? peripheral vascular disease (90%).
Severe trauma, burn, frostbite.
Dangerous? malignant tumor
Potentially lethal sepsis(gas gangrene)
Crush injury(crush syndrome)
Damn nuisance? when retaining a limb is worse than no
limb because of pain, gross malformation, recurrent sepsis,
loss of sensation(with pressure ulcer) or severe loss of function.
Varieties:
Provisional amputation: if primary healing is unlikely, amputation is done as distal as possible. The skin is closed loosely over a pack. Re-amputation is performed when stump condition is favorable.
Definitive end-bearing amputation: done if weight is to be taken through end of the stump, so the scar should not be terminal & the
bone should not be hollow e.g. through knee &Syme s amputations.
Definitive non-end-bearing amputation: the scar can be
terminal e.g. all upper limb &most lower limb amputations.
Amputation at the site of election: we elect a site that fits the
demands of prosthetic design for optimum function. Otherwise,
the stump may be too short & slip or too long which may become
painful &ulcerate due to ischemia or interfere with prosthetic function.
Technique: a tourniquet is used unless there is arterial insufficiency.
Skin? adequate equal anterior &posterior flap. For below knee
use long posterior flap.
Muscle? are sutured over bone end to each other &to the periosteum.
Nerves? are cut proximal to bone end.
Bone? for below knee: fibula is cut 3cm shorter than tibia.
Vessels? main vessels are tied & control any bleeding point.
Skin? is closed without tension over a drain with firm bandage.
Aftercare? repeat bandaging till have a conical stump.
Encourage muscle exercise. Joints should be
kept mobile &start using the prosthesis early.
Amputation other than at the site of election:
Forequarter (interscapulothoracic) amputation: done
for severe trauma or to eradicate malignant tumor.
Shoulder disarticulation: if humerus head is left? better appearance.
If 2.5cm of humerus can be left? can hold a prosthesis.
Below elbow(transradial) amputation: the shortest stump to hold a prosthesis is 2.5cm below a flexed elbow.
Hindquarter (hemipelvectomy) amputation: for
malignant tumor.
Hip disarticulation: if head, neck &trochanters
can be left? can fit a prosthesis.
Transfemoral amputation: at least 12cm
should be left for knee mechanism.
Through knee amputation: for vascular disease
& for children.
Below knee(transtibial) amputation: if <3cm stump? slip.
At least 5- 6cm a stump to fit a prosthesis.
The ideal is 14cm, if longer ? it has no advantage.
Above ankle(Syme s) amputation: just above the malleoli &
the fibrofatty tissue of the heel should stuck to the bone ends.
Used for men &children.
Partial foot amputation:
through midtarsal joint(Chopart),
through tarsometatarsal joints(Lisfranc),
through metatarsal bones,
through MPJ or better through proximal phalanx,
ray amputation: toe + it s metatarsal (for diabetic).
Prostheses:
A prosthesis must fit comfortably, function well &look presentable.
It should also be used early.
Electrically powered prosthesis for the upper limb has developed.
In the lower limbs, the weight is transmitted through:
ischial tuberosity, patellar tendon, upper tibia or through soft tissue.
Recently, a total contact prosthesis is more comfortable.
Complications of amputation stumps:
Early:
1- secondary hemorrhage: due to infection.
2- breakdown of skin flap: due to ischemia or
suture under excessive tension.
3- gas gangrene: may occur in high thigh amputation
if the site is contaminated from the perineum
especially if the stump is ischemic.
Late:
1- Skin: Eczema & tender inguinal LN, ?? rest from prosthesis.
Ulceration due to ischemia, ? ? re-amputation at higher level.
2- Muscle: if too much is left at the stump, it leads to unstable
cushion &insecure prosthesis, ?? excise the excess tissue.
3- Artery: poor circulation may lead to ulceration, ??
re-amputation.
4- Nerve:
Tender neuroma, ?? the nerve should be cut more proximally
&buried within the soft tissue away from pressure points.
Phantom limb: feeling of amputated limb is still
present, later this recedes or disappears. A painful
phantom limb is difficult to ?, though, intermittent
percussion to the end of the stump may help.
5- Joint: the joint proximal to the stump may be stiff
or deformed e.g. knee fixed flexion in below knee
amputation which makes walking difficult.
6- Bone:
Bony spur: usually painless, if there is infection it may
become larger &painful, ?? excision of bone end with spur.
Fracture: if the bone is transmitting little weight, it become
osteoporotic & may fracture, ?? ORIF