Chapter 10- Amputations

Question 1

What is an important consideration for lower limb amputations

Answer 1

-Lower limb amputation is designed to be weight- bearing- the emphasis is that the stump must be able to transmit load comfortably without pain/ repeated breakdowns of skin

Question 2

What should be done to the muscles in above the knee amputations

Answer 2

• Muscles should either be sutured to each other to cover the cut end of the bone
• OR anchored to the bone with sutures through drill holes
• Prevent retraction of the muscles and pressure of the bone on the skin

Question 3

Full thickness skin flaps or split skin grafts?

Answer 3

Use full thickness skin flaps whenever possible- split skin grafts are rarely adequate and breakdown under pressure of the prothesis

Question 4

What is the bone cut for below the knee stump

Answer 4

-patient’s hand breadth below the tibial tubercle or a minimum of 5 cm in order to fit a PTB type of prosthesis

Question 5

What is a bone cut for above the knee stump

Answer 5

-A knee mechanism will take up approximately 10 cm of space, so stump should be at least 10 cm shorter than the opposite thigh

Question 6

In partial foot amputations how should the bone be covered

Answer 6

The plantar skin should be flapped over the bone wherever possible, as it is thicker and more resistant to pressure than the thin and fragile dorsal skin

Question 7

What should be done to the physis in amputations in growing children

Answer 7

• Should be transposed to the end of the bone

- A disarticulation is preferred in children

Question 8

How should hip disarticulations and hind quarter amputations be rehabilitated

Answer 8

They are better rehabilitated on crutches or in a wheelchair, rather than in costly and cumbersome prostheses

Question 9

What is the overall emphasis for upper limb amputations

Answer 9

• The emphasis is to maintain as much length as possible, and with sensate skin over the end of the stump

Question 10

Where should a skin graft be placed for upper limb amputation

Answer 10

Away from the functional areas of the stump

Question 11

What are the necessary characteristics of a skin flap in an amputation

Answer 11

• Well perfused
• Full thickness
• Sensate skin

Question 12

In vascular insufficiency, how should the level of the amputation be decided

Answer 12

• Preferable to go more proximal ab initio

- The final level will be decided intra-operatively depending on the adequate bleeding of muscle and skin edges

Question 13

How is the level of the amputation decided in tumor surgery

Answer 13

• Emphasis on adequate margin of healthy tissue
• Usually 3-4 cm proximal to the lesion is decided on MRI or other imaging
• Intraoperative frozen section is used to ensure the presence of normal tissue

Question 14

When to use a tourniquet in an amputation

Answer 14

• should not be used in vascularly deficient limb
• May applied in trauma to gain control of the bleeding, release as soon as vascular control has been attained
• Elective amputation in a well perfused limb under a tourniquet, release prior to closure to ensure adequate haemostasis

Question 15

What should one do with vessels in an amputation

Answer 15

• Major vessels should be ligated twice, with non-absorbable sutures such as silk
• Smaller vessels can be tied with absorbable suture such as chromic catgut or diathermised

Question 16

What should one do with nerves in an amputation

Answer 16

-Pull gently on the nerve, cutting it with a sharp blade and allowing it to retract amongst the proximal muscles

Question 17

When an how to drain the stump

Answer 17

• All amputations should be drained
• Suction drains are seldom adequate
• Corrugated drain is the most effective method to prevent accumulation of a haematoma in an amputation stump

Question 18

How should skin be closed in an amputation

Answer 18

Should be closed with small, 3-0 interrupted non-absorbable sutures, which are places close together to ensure good healing of the stump. Suture line away from the weight bearing area.

Question 19

What are the most important aspects of post-op management

Answer 19

• Avoiding flexion contractures of the hip and knee joint: above the knee amputations, patients encouraged to lie prone for several hours each day, below the knee amputations- sit with knee extended on board
• Get the patient mobile: before prostheses, mobilise with crutches, wheelchair, walking frame
• Conditioning the stump for prosthetic fitting: achieve cone shape of stump through a bandaging technique (Bandage replaced at least three times daily), pressure garment may be substituted

Question 20

Correct stump care

Answer 20

• Stump washed and well dried before applying and after removing the prosthesis
• Stump socks must be used and changed regularly
• The stump will shrink over the first 12-18 months and the prosthesis may have to be re-fitted to correct this
• The stump should be checked carefully daily for open skin lesions, and the prosthesis left off until such areas have healed

Question 21

Prosthetics for partial foot amputations

Answer 21

If part of the foot retained, not possible to fit a prosthetic foot as there is no space for it.
Patients require a shoe filler to stop the foot slide in the shoe
Remnant of foot very small –> ankle lace up boot

Question 22

Prosthetic for below knee amputation

Answer 22

With minimum of 5 cm of stump and stable knee ligaments, a non-suspended prosthesis may be used, such as a PTB. If stump shorter- prosthesis extends tot he thigh and is anchored with a thigh corset and side irons and hinges for stability

Question 23

Prosthetic for above knee amputation

Answer 23

Above knee prosthesis rely on suspensory harness, either worn around the patient’s waist or over the shoulder. In addition, a knee mechanism must be included in the prosthesis

Question 24

Prosthetic for a hip disarticulation

Answer 24

Canadian tilting table. No hip joint ambulation so rely on trunk and spine movement

Question 25

Most functional upper limb prostheses for upper limb in public

Answer 25

Split hook