Digital Amputations

Updated: Nov 02, 2015
  • Author: Bradon J Wilhelmi, MD; Chief Editor: Harris Gellman, MD  more...
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Overview

Background

An amputation is the removal of an extremity or appendage from the body. Amputations in the upper extremity can occur as a result of trauma, or they can be performed in the treatment of congenital or acquired conditions. Although successful replantation represents a technical triumph to the surgeon, the patient's best interests should direct the treatment of amputations.

The goals involved in the treatment of amputations of the upper extremity include the following [1, 2] :

  • Preservation of functional length
  • Durable coverage
  • Preservation of useful sensibility
  • Prevention of symptomatic neuromas
  • Prevention of adjacent joint contractures
  • Early return to work
  • Early prosthetic fitting

These goals apply differently to different levels of amputation.

Treatment of amputations can be challenging and rewarding. It is imperative that the surgeon treat the patient with the ultimate goal of optimizing function and rehabilitation and not become absorbed in the enthusiasm of the technical challenge of the replantation, which could result in poorer outcome and greater financial cost due to lost wages, hospitalization, and therapy.

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Indications

Amputations can result from traumatic injury involving a variety of machines, they can be self-inflicted, or they may be required after traumatic events, such as electrical burns or frostbite. In addition, elective amputations may be indicated for tumor extirpation, vascular insufficiency, infection, or congenital malformation.

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Technical Considerations

Anatomy

The basic skeleton of the wrist and hand comprises a total of 27 bones. The hand is innervated by 3 nerves—the median, ulnar, and radial nerves—each of which has sensory and motor components. The muscles of the hand are divided into intrinsic and extrinsic groups.

The hand contains five metacarpal bones. Each metacarpal is characterized as having a base, a shaft, a neck, and a head. The first metacarpal bone (thumb) is the shortest and most mobile. It articulates proximally with the trapezium. The other four metacarpals articulate with the trapezoid, capitate, and hamate at the base. Each metacarpal head articulates distally with the proximal phalanges of each digit.

The hand contains 14 phalanges. Each digit contains three phalanges (proximal, middle, and distal), except for the thumb, which only has two phalanges. To avoid confusion, each digit is referred to by its name (thumb, index, long, ring, and small) rather than by number.

Important anatomy to understand in performing digital amputations includes the various structures of the digit, such as the digital nerves, the digital arteries, the flexor digitorum profundus (FDP), the flexor digitorum superficialis (FDS), the extensor tendons, the collateral ligaments, the volar plate, the dorsal capsule, and the components of the nail. When amputations are performed at various levels, it is important to understand the critical anatomy to optimizing resultant function.

For amputations at the distal interphalangeal (DIP) level, volarly the FDP is severed and allowed to retract proximally. The digital neurovascular bundles can be found on the radial and ulnar border of the distal digit at the DIP crease to be at the level of their trifurcation. These neurovascular bundles course between the Grayson and Cleland ligaments volarly and dorsally, respectively.

The digital nerves are longitudinally retracted and severed to allow retraction (so-called traction neurectomy) to prevent neuroma formation at the tip. The digital arteries are bipolar-coagulated to minimize bleeding. These neurovascular structures can be located longitudinally along this vector throughout the digit between the Grayson and Cleland ligaments. Each joint is stabilized by the radial and ulnar collateral ligaments, and the volar plate and dorsal capsule may require severing to detach the adjacent phalanx.

For more information about the relevant anatomy, see Hand Anatomy.

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