General Principales of Amputation in limb.ppt
- 1. Whether an amputation is done primarily or secondarily, certain principles must be observed to obtain a painless and useful stump.
- 2. General principles for amputation surgery involve appropriate management of skin, bone, nerves, and vessels. Avoid unnecessary dissection between skin and subcutaneous, fascial & muscle plane.
- 3. The volar skin flap should be long enough to cover • The volar surface • The tip of the osseous structures • To join the dorsal flap without tension. • The classic flap is rare, a flap of a different shape can be improvised, but the end of the bone must be padded well. •The digital arteries should be cauterized
- 4. The ends of the digital nerves should be Dissected carefully from the volar flap Gently placed under tension so as not to rupture more proximal axons, and Resected at least 6 mm proximal.
- 5. Flexor and extensor tendons should be drawn distally, divided, and allowed to retract proximally.
- 6. When an amputation is through a joint, the flares of the osseous condyles should be contoured to avoid clubbing of the stump. Before the wound is closed, the tourniquet should be released and bleeding controlled because hematomas are painful and may delay healing.
- 7. Amputation and shortening of the digit may be indicated when there is less then 5 mm of sterile matrix. If flexor and extensor insertions cannot be left intact, then the distal phalanx should be disarticulated. Nail bed: The nail matrix extends proximal to skin fold, extensive dissection may be necessary to remove it completely.
- 8. Amputations of the fingertips depending on the amount of skin lost, the depth of the soft- tissue defect, and whether the phalanx has been exposed or even partially amputated. Injuries with loss of skin alone can heal by secondary intention or can be covered by a skin graft. If the soft-tissue defect is deep and the phalanx is exposed deeper tissues and skin must be replaced
- 9. Crushing injury that destroys the distal phalanx and a portion of middle phalanx necessitates amputation thru the middle phalanx. If insertion of FDS into base of middle phalanx can be preserved, some function of PIP joint may be preserved If insertion of the tendon has been avulsed, there is little reason to preserve the middle phalanx, and disarticulation thru PIP joint may be considered.
- 10. Index Finger When the index finger is amputated at its proximal interphalangeal joint or at a more proximal level, the remaining stump is useless and can hinder pinch between the thumb and middle finger. secondary amputation should be through the base of the second metacarpal.
- 11. In contrast to the proximal phalanx of the index finger, the proximal phalanx of either the middle or the ring finger is important functionally. Its absence in fingers makes a hole through which small objects can pass when the hand is used as a cup. Its absence makes the remaining fingers tend to deviate toward the midline of the hand The third and fourth metacarpal heads are important too because they help stabilize the metacarpal arch by providing attachments for the transverse metacarpal ligament.
- 12. Excising the third metacarpal shaft removes the origin of the adductor pollicis and weakens pinch. Transposing the index ray ulnarward to replace the third ray may be indicated. This operation results in more natural symmetry, Similarly, when the ring finger has been amputated, transposing the fifth ray radialward to replace the fourth.
- 13. As much of the little finger as possible should be saved. It becomes important in forming pinch with the thumb When the little finger alone is amputated, then appearance of the hand is important. The fifth metacarpal shaft is divided obliquely at its middle third; the insertion of the abductor digiti is transferred to the proximal phalanx of the ring finger.
- 14. In partial amputation of the thumb reamputation at a more proximal level to obtain closure should not be considered because the thumb rarely should be shortened. The wound should be closed primarily by a free graft, an advancement pedicle flap , a local or distant flap. If a flap is necessary, taking it from the dorsum of the hand or the index or middle finger is preferable.
- 15. Covering the volar surface of the thumb with an abdominal flap is contraindicated. thin abdominal skin and fat provide a poor surface for pinch, because they lack fibrous septa and roll or shift under pressure. Skin of the abdomen is dissimilar in appearance to that of the hand and its digits.
- 16. When amputation has been at the metacarpophalangeal joint or at a more proximal level, reconstruction of the thumb may be indicated Function of the thumb can be improved by deepening its web by Z-plasty. and by osteotomizing the first and fifth metacarpals and rotating their distal fragments toward each other Or tilting the fifth metacarpal toward the thumb. If the first carpometacarpal joint is functional, but the first metacarpal is quite short, the second metacarpal can be transposed to the first to lengthen it and to widen and deepen the first web.
- 18. In partial amputations of all fingers, preserving the remaining length of the digits is much more important. Because of the natural hinge action between the first and fifth metacarpals. Remaining stump of the little finger must play an important role in prehension with the intact thumb. this hinge action can be increased about 50% by dividing the transverse metacarpal ligament between the fourth and fifth rays.
- 19. In partial amputation of all fingers and the thumb, function can be improved by lengthening the digits and by increasing their mobility.
- 20. Thank you