1. Chapter 42 Lower Extremity Amputation
Orthopedic Knowledge Update 選讀
Chapter 42 Lower Extremity Amputation
~ Hans L. Carlson, MD ~
Presenter: R2張瑋倫
Supervisors: VS黃國淵

2. Introduction Current terminology: Before  Now AK Transfemoral  No.2
BK Transtibial  No.1
Etiology:
trauma (most common in younger), peripheral vascular dx (most common in older), tumor, congenital deformity……

3. Introduction From amputation to successful ambulation
1.wound healing  remove suture (3~4 wks)
2.wears a shrinker sock (1~3 wks)
3.Fabrication of prosthesis
4.when tolerate standing in the prosthesis for 15 mins, start gait and balance training (4~8 wks)
* donning and doffing

4. Level of Amputation
Variables: blood supply, tissue oxygenation, nutritional state, prosthetic fit, available components.
In general, energy expenditure is increased and gait proficiency is decreased the more proximal the level of amputation.

5. Level of Amputation In choosing a level for amputation,
prosthetic management also needs to be
considered. For example,

6. Level of Amputation – Syme’s amputation (Ankle disarticulation)
Be good for function, due to long lever & can weight bearing. (but need a rigid socket support)
The prosthetic foot options less than BK.
A poorer cosmetic prosthetic result because of the need to accommodate the bulbous distal shape of the residual limb
Careful surgical technique is required to prevent heel pad migration from the distal end of the residual limb. If this occurs, the weight-bearing advantage of this amputation level could be compromised

7. Level of Amputation – Knee disarticulation VS. TF
Be good for function, due to long lever.
Preserve thigh muscle, leading to better muscle balance
Bulbous shape make prosthesis more stable
Limitation in knee-joint prosthetic component
No enough flap, so increased tissue trauma, and pain.

8. Length of Amputation Important issues:
1. length of usable lever arm, which also determines the power and amputee will have for ambulation
2. remaining space for available components.
3. cosmetic appearance.

9. Length of Amputation Ideal length:
Transtibial: where the U/3 to M/3 meet. It allows the gastrosoleus muscles with a long posterior flap to serve as padding.
(Campbell 11th: nonischemic cm or 2.5cm/30 cm body height; ischemic cm )
Transfemoral: preserve 50% to 75% of the femur.

10. Technique: Transtibial Amputation
Beveling (斜角切) the distal tibia and fibula will be helpful in minimizing trauma
Ertl procedure:
a revision procedure in pt who have continued pain long after the initial amputation.
Create a bony synostosis between tibia & fibula
1.stabilize fibula so increased bony surface area for weight bearing
2.close medullary canal to recover normal bony pressure & nutrition, so that decreased pain.

11. Postoperative Dressings
Goals: improve wound healing, control pain, protect residual limb, speed the process for prosthetic fitting.
Most commonly, simple gauze + elastic wrap
“Postoperative dressing and management strategies for transtibial amputations: A critical review”. J Rehabil Res Dev 2003:40:
 rigid plastic dressing may lead to a shorter time to initial gait training, the type of dressing management did not affect outcomes of using a prosthesis, time to ambulation, or fitting of the final prosthesis.

12. Postoperative Rehabilitation Management
Should start even while the wound is healing.
For successful ambulation,
TT: 1.need at least 80% strength of uninjured leg
2.up to 70 degree of knee flexion
TF: no limitation in hip ROM, even can tolerate < 10 degree contracture
Early Mobilization: can avoid adherence between superficial and deep tissue (cause pain), and may help to tolerate phantom pain.

13. Postoperative Rehabilitation Management
Residual limb pain:  69.2% #
pain located within residual limb
Phantom limb pain:  41.8% #
pain perceived to be coming from the missing portion of the limb.
 Tx: neuroma excision ;
gabapentin or pregabalin (antiepileptic, TCA, opioid)
46~90% pt of lower extremities amputees wound have pain 1 yr following their amputation.
( # 46~90% pt of lower extremities amputees wound
have pain 1 yr following their amputation.)

14. Prosthetic Management
As the surgical incision heals, the use of elastic wraps or shrinker socks can help to control edema and speed the process of the reshaping of the residual limb. These techniques will allow the new lower extremity amputee to be fit with the prosthesis earlier, and ambulate earlier.

15. Preparatory Prosthesis
An initial prosthesis designed to accommodate radical changes in shape or volume through manipulation of a socket insert. (usually worn 4~6 months.)
Definitive Prosthesis
………without socket insert
For “mature” residual limb

16. Exoskeletal system Endoskeletal system
Advantage: durability and its ability to transfer the load applied from the socket to the foot. When an amputee requires great durability in a prosthesis, such as for farming.
Disadvantage: not adjustable
Endoskeletal system
Avantage: adjustable

17. Thank you for your attention

18. Hip Disarticulation Prosthesis

19. Tranfemoral Prosthesis Endoskeletal

20. Tranfemoral Prosthesis Exoskeletal

21. Knee Disarticulation Prosthesis

22. Transtibial Prosthesis Endoskeletal

23. Transtibial Prosthesis Exoskeletal

24. Partial Foot Prosthesis w/ Toe Filler