Amputation of the Finger and Hand

- See:
        - Phalangeal Menu:
             - finger tip injuries
             - replantation of the digits
             - soft tissue replacement in the hand and forearm:
             - upper extremity amputations:

- Basic Principles of Phalangeal Amputation:
    - skin incision should be mid-axial on both sides of digit;
    - contour articular condyles - volar and lateral
    - if tendon insertion site absent, sever tendon and allow it to retract
    - do not suture flexors to extensors
    - dissect nerves and sharp proximal transection (gental pull);
    - be certain nerves are away from cutaneous scar;
    - volar flaps are preferable;

- Quadriga:
    - weak grasp in remaining fingers due to FDP tethering by scar at amputation site (eg suturing FDP to extensors);
    - if one FDP is tethered, the others can not shorten;

- Surgical Technique for Amputation of the Distal Phalanx:
    - see: finger tip injuries:
    - indications:
           - amputation and shortening of the digit may be indicated when there is less then 5 mm of sterile matrix, since nail adherence will be losed;
    - nail bed:
           - see: nail bed anatomy
           - because the nail matrix extends considerably proximal to skin fold, extensive dissection may be necessary to remove it completely;
    - w/ transverse amputations, create distal midlateral incisions on both sides of the digit, to allow easier access to nerves, the phalanx, and to allow easier flap closure;
    - shorten and contour bone for primary closure;
           - insertions of flexor and extensor tendons on most proximal portion of the distal phalanx should be left intact if possible;
           - if flexor and extensor insertions cannot be left intact, then the distal phalanx should be disarticulated;
                  - in this case, the flexor and extensor tendons are placed under traction, transected, and are allow to retract;
                  - a ronguer can be used to contour the volar condyles of the middle phalanx;
    - digital nerves are transected as proximally as possible;
    - volar skin flap is created & wound is closed dorsally;
           - inorder to avoid a club deformity, place the initial suture centrally, and then draw the palmar skin proximally over the dorsal stump;
                  - incise the overlapping portion of the dorsal skin (which typically extends 45 deg from the central stitch);
                  - the resulting scar resembles an inverted horseshoe;
    - complications:
           - lumbrical plus finger:
                  - can occur after amputation of the distal phalanx if the lumbrical muscle is not released (along w/ release of the FDP);
                  - the result is that the FDP becomes a paradoxical extensor of the PIP joint, since the FDP can now act only thru the lumbrical's insertion into the lateral
                          band (which coarse dorsally into the triangular ligament); 
     - neuroma formation:
              - A new operation for the prevention and treatment of amputation neuromas

- Amputation thru the Middle Phalanx:
    - 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 as well;
    - 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;
    - if sharp clean injury, shorten and contour bone for primary closure;
    - preserve FDS insertion;

- Proximal Phalanx Amputation:
    - frequently need dorsal skin flap for closure
    - intrinsics control flexion;
    - lasso procedure:
          - one of the flexor tendons (preferably the FDS) is kept long enough to pass around the A2 pulley, when is then sutured back to itself; 
          - adjust tension, so that full extension is possible;

- Amputation of Finger and Ray:
    - occassionally entire finger must be amputated because of severe injury aggressive infection, or malignant tumor;
    - ray resection may also be required for traumatic proximal phalanx amputation with neuroma;
    - generally the distal half of the respective metacarpal is resected as well (ray amputation);
    - ray resection is most often a consideration in the index finger, however, this is usually done as a staged procedure (allowing the patient to make the decision);
            - ray resection can be performed either through a dorsal or volar approach;
            - palmar approach to ray resection:
                   - allows for more cosmetic scar, allows for easier access of nerves (when a neuroma is present), and allows for easier taloring of bone w/ oblique osteotomy;
    - technical options of ray resection include resection with or without transposition;
            - disadvantages of transposition: patients may be left with decreased grip strength, scissoring of adjacent fingers, and difficulty grasping small objects;
    - carpo-metacarpal disarticulation:
            - there is no purpose to midcarpal amputation;
            - do not save the the proximal row or single carpal bones, esp if amputee is unilateral;
    - avoidance of neuroma:
            - consider digital nerve transposition into superficial veins;
    - references:
            - Index transposition after resection of the long finger ray.
            - Total middle ray amputation.
            - Functional assessment of ray transfer for central digit loss.  
            - Results of central ray resection without bony transposition.  
            - Hand function following single ray amputation.  
            - Results of ray resection and amputation for ring avulsion injuries at the proximal interphalangeal joint.
            - Single Ray Amputation for Tumors of the Hand

- Wrist Disarticulation:
    - while the stump will pronate and supinate, the socket will not permit this axial rotation;
    - this level is useful because of the strong, durable stump, not because of the radioulnar rotation

Profundus tendon blockage: quadriga in finger amputations.

Intraosseous nerve transposition for treatment of painful neuromas.

Surgery of hand and finger amputations.

A new incision for amputation of the index finger and its metacarpal.    

Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Friday, May 11, 2012 1:18 pm