Fingertip Amputation 

Fingertip injuries are one of the most common injuries of the hand, and appropriate treatment depends on the type of injury and the involvement of other digits.

Fingertip amputation occurs distal to the insertion of flexor or extensor tendons into the distal phalanx. Numerous techniques are available for the repair of fingertip amputations, with the common goal to reduce pain and preserve sensation at the tip.^[1] The appropriate approach depends on the amount of tissue involved, the involvement of bone (distal phalanx), the angles and levels of amputation, and the involvement of other fingers or the rest of the hand.

Functional requirements differ with each individual, and as such, management options must be discussed with the patient. Management starts with history elicited from the patient regarding the nature of the injury, age, hand dominance, occupation, recreational activities (including playing sports and musical instruments), previous history of hand injuries or problems, and other systemic diseases that affect wound healing.

A complete hand examination should be performed, estimating the amount of injury to the fingertip, angles and levels of amputation, loss of tissue, involvement of nail, involvement of other fingers, neurovascular involvement, and function of the hand. Investigations include radiographs of the affected finger to reveal whether the injury is associated with any underlying fractures or foreign bodies, as fractures may require further treatment. After assessing the fingertip injury, a treatment plan should be formulated. If more than one option is available, the potential benefits and risks of each option should be discussed with the patient before the final treatment is selected.

The geometry of the defect dictates the management of most fingertip injuries. The loss of tissue at the fingertip may be transverse or oblique, with more tissue loss on the volar side or on the dorsal side. Some amputations may take more tissue from one side or the other, ie, radial or ulnar. See image below.

The different techniques available to repair fingertip amputations and discussed in this article are as follows:

1. Open technique (nonoperative; healing by secondary intention)
2. Skin graft
3. Reamputation
4. V-Y flap (Kutler or Atasoy)
5. Volar flap advancement (Moberg)^[2]
6. Bipedicle dorsal flap
7. Crossfinger flap
8. Thenar flap

Each one of these techniques is discussed separately in the sections below.

• Open technique: If the fingertip injury is less than 1 cm², or if the fingertip injury is in a child with adequate soft issue cover over the bone, the injury can be managed nonoperatively with secondary healing.
• Skin graft: Larger fingertip injuries that cannot be managed nonoperatively with healing by secondary intention alone, ie, those with a thin layer of epithelium that is not durable, can be treated with skin grafts taken from the hairless ulnar side of the hand.
• Reamputation: If the bone is protruding, the bone can be shortened and primary closure can be performed, or the wound can be left open for healing by secondary intention with granulation tissue. This can be performed in adults with injuries that have less than 5 mm of sterile nail matrix present. It is also relatively indicated in patients with significant systemic conditions, for whom regional flaps are contraindicated and the other techniques like skin graft or open technique are not possible.
• V-Y flap: This is indicated if the angle of fingertip amputation is either oblique with more tissue loss dorsally or transverse. It can be performed only if significant palmar tissue is available for dorsal advancement.
• Volar flap advancement: This technique was previously used for all fingers; recently, it is recommended for use only in thumb fingertip amputation in which less than 1.5 cm of advancement is required for coverage. In other fingers, the venous drainage depends on the volar flap, so this technique increases the risk of necrosis of the entire flap.
• Bipedicle dorsal flap: This technique is indicated only in cases in which the fingertip amputation is proximal to the nail bed and preserving all its remaining length is essential but attaching to another finger is not desirable.
• Crossfinger flap: This technique is indicated when local flaps are not possible and maintaining the remaining length is essential. It is especially useful in multiple digit injury, where maintenance of length in the remaining injured fingertips is considered essential.
• Thenar flap: This technique is indicated in any fingertip amputation with exposed bone.

• Open technique: This technique is contraindicated in any fingertip amputation with exposed bone. It is relatively contraindicated in injuries in adults that include tissue loss of more than 1 cm².
• Skin graft: Skin graft alone is insufficient in fingertip amputation with exposed bone.
• Reamputation: This technique is relatively contraindicated in cases in which maintaining remaining length is essential. Otherwise, this procedure can be performed in most cases, though it is not always advantageous because length is lost.
• V-Y flap: This technique is contraindicated when the geometry of the fingertip amputation is oblique with more tissue loss on the volar side. Further, this procedure is not possible with more proximal fingertip amputations.
• Volar advancement flap: Volar flap advancement is relatively contraindicated in fingers other than the thumb, as it may result in necrosis of the whole flap. Also, if the defect is more than 2 cm, this technique should not be used.
• Bipedicle dorsal flap: This technique is not possible when the fingertip amputation is very distal and in cases where the soft tissue loss is significantly at the sides.
• Crossfinger flap: This technique is avoided in patients older than 50 years and in hands with arthritis or a tendency toward finger stiffness. It is also avoided if local infection is present.
• Thenar flap: Any tendency for finger stiffness is a relative contraindication to this procedure.

Fingertip amputations can be performed under general anesthesia or regional anesthesia. Regional anesthesia is generally preferred, and many simple procedures can be performed with digital blocks. If multiple fingers are involved because of the injury, or proximal tissues are involved either as a flap or skin graft, then a Bier block or general anesthesia may be used.

Preferred anesthesia for each procedure is as follows:

• Open technique: Digital block for pain control, including during cleaning and dressing
• Skin graft: Wrist block, Bier block, general anesthesia
• Reamputation: Digital block
• V-Y flap: Digital block
• Volar flap advancement: Bier block, general anesthesia
• Bipedicle dorsal flap: Bier block, general anesthesia
• Cross-finger flap: Wrist block, Bier block, general anesthesia
• Thenar flap: Wrist block, Bier block, general anesthesia

Digital nerve blocks can be performed as either volar or dorsal approach. The author prefers to use the dorsal approach, since the volar approach usually results in incomplete dorsal anesthesia. Because of this, more anesthetic may be required to be administered locally or dorsally to numb the dorsal digital nerves. For more information, see Anesthesia, Regional, Digital Block.

• Volar approach

  1. Prepare area with antiseptic solution.
  2. Pass needle over the flexor sheath at the level of metacarpophalangeal joint, then direct the injection on either side of the flexor tendon.
• Dorsal approach

  1. Clean the web spaces at the base of the finger with antiseptic solution (preferably chlorhexidine).
  2. Insert needle into the dorsal skin, brushing aside the head of the metacarpal.
  3. Before inserting deep, create a wheal dorsally by injecting local anesthetic to the dorsal skin, blocking the dorsal digital nerves.
  4. Then direct the needle volarly and block the digital nerves by injecting additional local anesthetic.
  5. With such an injection, the widening of webspace may be seen.
  6. Repeat the same procedure on the other side of the metacarpal.

• The choice of surgical instruments is left to the surgeon. In general, a basic surgical tray is all that is needed. Possible instruments include the following:

  • Hand surgery instruments - scissors, retractors, needle holders, scalpel, forceps, clamps, elevators
  • Bone instruments (if bone end needs to be trimmed) - drill and accessories, osteotomes, mallet, retractors, curettes
  • Tendon and nerve repair instruments - tendon strippers
  • Irrigation supplies (for wound cleaning)

• Position the patient supine on the operating table with the affected arm supported over an arm board.
• For procedures involving areas proximal to the metacarpophalangeal joint (MCPJ), an arm tourniquet is used.
• For procedures not involving areas proximal to the MCPJ, a digital tourniquet can be used. A digital tourniquet can be made at the operating table with an elastic glove.

  • Cut off a finger of a glove. Cut the tip off, as well, so that it looks like a cylindrical tube with openings at both ends.
  • Insert the tube on the finger starting distally and gently rolling down proximally until it reaches the base of the finger. This procedure of rolling the tube down the finger acts to exsanguinate the finger.
  • When the base is reached, a small curved artery forceps is used to hold the rolled tube and then rotated to act as a tourniquet.

Open technique

• This is nonoperative management of fingertip amputation in which the loss of skin or pulp is less than 1 square cm, which can heal by secondary intention.
• The wound needs cleaning and dressing at regular intervals. Advise the patient to begin 1 week after the procedure to soak the finger in warm water–peroxide solution daily and then apply the dressings with a fingertip protector.
• In selected cases, where the tip of the bone is exposed, it can be trimmed with bone cutters to the level of the soft tissues and then allowed to heal by secondary intention. However, better results are usually achieved in such cases if an additional procedure is performed.
• Complete healing takes place in 3-6 weeks.

Skin graft

• Larger wounds allowed to heal by secondary intention may result in a thin, nondurable layer of epithelium. In such cases, skin grafting from the palmar surface is preferred, and these are generally taken as full-thickness skin grafts.
• The preferred donor site is the hypothenar area of the palm. The full-thickness skin graft taken from this site is durable and is an excellent cosmetic match to the pulp of the finger. Also, this donor site is convenient from the surgeon's perspective.
• When the full-thickness graft is taken, the underlying fat should be completely removed before applying.
• The other areas from which a full-thickness graft can be procured are the medial aspect of the arm distal to axilla, volar side of the forearm and wrist, and the amputated part of the fingertip, if it is available. The latter can be performed more successfully in children than in adults.
• Split-thickness grafts can also be performed; however, full-thickness grafts are preferable for their durability. Also, split-thickness grafts contract with time while healing.

Reamputation

• Shortening and primary suturing can be done in certain cases.
• When shortening is contemplated for fingertip injuries, remove the remaining germinal matrix of the nail to prevent future problems from the nail remnant. To do this, make incisions on either side of the nail wall and reflect the nail wall proximally, extending from the eponychium.
• If shortening leaves the patient with a stump of distal phalanx, carry out disarticulation at the level of distal interphalangeal joint.
• Remove the prominent volar condyles of the middle phalanx with a bone cutter or a rongeur.
• Pull the flexor and extensor tendons distally and transect them; then allow them to retract.
• Excise the palmar plate and the collateral ligaments to avoid bulking of the tip and give a better contour to the tip.
• To avoid painful neuromas, identify the digital nerves and dissect them proximally, then pull and transect them 1 cm proximally from the skin edge (tip).
• If the plane of the amputation is transverse, bring the palmar skin forward to suture with the dorsal skin. If a long flap of skin is available, as in cases where the plane of the injury is oblique, use the excess skin to cover the tip as a flap.
• Suture the skin without any dog ears.

V-Y flap

• After trimming the bone ends, in cases of distal transverse fingertip amputations, create a V-Y flap with a triangular flap that has the wound edge as its base. The apex should be the midpoint of the distal interphalangeal joint. Only the full thickness of the skin is cut. See image below. V-Y flap.
• Adequately mobilize this flap by passing a No. 15 blade tangentially on the volar aspect of the bone from the distal edge of the wound. Use the knife blade to divide all the fibrous septa anchoring the pulp to the underlying bone.
• Once it is completely mobilized, pull the flap over the fingertip and sutured it to the nail bed dorsally.
• At this juncture, release the tourniquet to assess the capillary refilling of the flap. A pale flap indicates that the flap is not adequately mobilized and that the vessels are stretched. In this case, remobilize the flap, taking care to divide all the fibrous septa anchoring the pulp to the underlying distal phalanx.
• Once satisfactory capillary refilling is present in the mobilized flap, close the rest of the wound with V-Y plasty without any tension.
• Recently, a dorsal V-Y flap is described in the literature, for volar oblique fingertip amputations with more volar soft tissue loss.^[3]

Volar flap advancement

• This flap is normally used for injuries to the tip of the thumb. See image below.Moberg flap.
• After the debridement of the fingertip, make midlateral incisions dorsal to the neurovascular bundles, and dissect the flap from the flexor tendon sheath.
• Mobilize the flap and advance it along with the neurovascular bundles. The advancement is helped by flexion of the interphalangeal joint of the thumb.
• If the flap is under tension, perform a transverse incision on the skin at the base of the flap. This results in a rectangular defect that needs a full-thickness skin graft.
• In the other fingers, the prospect of flap survival is increased by limiting the volar flap incisions distal to the proximal interphalangeal joint.

Bipedicle dorsal flap

• Start the incision at the proximal margin of the fingertip defect and proceed proximally on the dorsum of the finger to elevate skin and subcutaneous tissue.
• At a more proximal level, make a transverse dorsal incision to create a bipedicle graft to cover the defect at the fingertip.
• The flap can be made more mobile by dividing one of the pedicles; however, this comes with the price of increased chance of necrosis of the flap.
• Use a full-thickness skin graft from the volar aspect of the distal forearm to cover the defect created by taking the flap.

Crossfinger pedicle flap

• This technique needs proper planning, templating, and forming of a pattern before actually creating a flap. The technique also depends on the size and location of the defect and the other finger injuries.
• The flap can be based either proximally or distally. More commonly, the flap is taken from the neighboring ulnar finger with the base laterally. The flap is taken from the dorsal aspect.
• Keep the template 2 mm larger than the required size so that the final suturing can be done without tension.
• Dissect the flap down to the plane between the subcutaneous fat and the paratenon of the extensor tendon.
• Check the vascularity of the flap, and then apply it over the defect in the adjacent fingertip.
• Fill the defect in the donor area with a full-thickness skin graft taken from the groin.
• To minimize the chance of crossfinger pedicle flap failure, transfix the middle phalanges of the two fingers with K-wires. This prevents excessive tension and torsion of the flap.
• When the procedure is complete, apply a large bulky dressing.
• Detach the pedicle 2 weeks after the initial procedure.
• Gradually attempt mobilization for the fingers to avoid finger stiffness.

Thenar flap

• With the thumb in abduction, flex the injured finger so that the tip touches the thenar eminence. See image below.Thenar flap.
• Mark the margins of the flap so that enough tissue is available to suture without tension. Design the flap with the base proximally. The length of the flap should not be more than twice the width of the flap.
• Raise the flap with as much of the underlying subcutaneous fat and suture it to the fingertip without tension.
• Close the defect in the donor area primarily; a graft is not needed.
• The flap should not have any buckling or kinking that may interfere with the vascularity.
• Apply a large bulky dressing.
• After 48 hours, change to light dressing with the flap partially exposed.
• After 2 weeks, detach the pedicle.

Pediatric patients

• Amputations through the eponychium may be replanted with variable success. Revision amputation is usually performed at the level of the eponychium. If ≥25% of the nail bed is present, the patient benefits from maintaining that nail. However, resection is recommended if < 25% of the nail bed is present.
• In children, the tip of the finger is often avulsed with the nail bed. In such cases, approximations are made of the edge of the nail bed and skin tip as a composite graft. To hold the bone in place, longitudinal or crossed pins are used. The younger the child, the better adherence of composite graft of skin and nail bed are seen. The greatest success rates are seen in children aged 3 years or younger. However, in an older child, a cap graft is likely to hold greater success.

• Choice of technique depends on the geometry of the fingertip injury and, to a certain extent, the expertise of the surgeon.
• Watch carefully for flap necrosis. At the end of a flap procedure, check capillary filling for the flap after the tourniquet is removed.

Postoperative complications can be broadly divided into problems at the site of nail growth (sterile matrix) and problems at the site of nail support (distal phalanx).

• Sterile matrix problems: A scar within the sterile matrix can result in various deformities, such as notching, nonadherence, splitting, and elevation of the nail. Such problems prevent growth or adherence to the nail bed scar.
• Distal phalanx problems: Overdebridement can result in an uneven dorsal cortex and loss of bony support, resulting in nonunion of the distal phalanx or osteomyelitis.

Early postoperative complications of an amputated stump include wound hematoma, infection, and necrosis. To minimize the risk of infection, irrigation and debridement of the amputation wounds is required. Hemostatic control of the amputation stump can be achieved initially with a tourniquet.

If subungual hematoma or seroma is present 5-7 days after surgery, reopen the nail trephination hole or gently raise the nail at the paronychia to permit drainage. The suture used to hold the nail in place should be removed 5-7 days after the injury to prevent a sinus tract formation through the nail fold. In simple subungual hematoma, regardless of size, nail removal with suture repair of the nail bed is unnecessary. For more information, see eMedicine article Hand, Subungual Hematoma Drainage.

Particular techniques are predisposed to particular complications, as described below.

Open technique

• A small number of patients report insensitivity at the tip of the fingers.
• Fingertip amputations managed by open technique after shortening the protruding bone result in nail plate deformities.

Skin graft

• Induration or fissuring of the graft with reduced sensibility in the area of the finger is common; less than half of patients who undergo split skin graft experience cold sensitivity in the affected finger.
• Split skin graft has the additional complication of contraction to half its original size.

Reamputation

• Painful neuroma may occur.
• Loss of height occurs; if the finger is too short, this can impair the function of the hand.
• Distal accumulation of soft tissue can result in poor cosmesis.

V-Y flap

• Abnormal finger tip sensation is infrequent.
• Flap necrosis is relatively rare.

Volar flap advancement

• Flap necrosis is an important problem in fingers (not including the thumb); it is associated with significant incidence of flexion contractures.
• Flap necrosis can also result from injury to the neurovascular bundles.

Bipedicle dorsal flap

• Flap necrosis is the main concern with this technique, but it is a rare complication.

Crossfinger flap

• Flap necrosis is the main concern with this technique.
• Finger flexion contracture may also occur.

Thenar flap

• Flexion contracture of the injured finger is the main concern; hence, this technique is not advised in patients with underlying conditions that predispose finger stiffness.

New techniques have recently been described, including palmar pivot flap for lateral defects in the fingertip injuries^[4] and reverse midpalmar island flap for complex reconstruction of fingertip amputations.^[5] However, these techniques are new and are not yet commonly used in many centers.