Thursday, August 16, 2007

Fingertip Injuries/Amputations

Fingertip (or pad) injuries are very common. They range from simple lacerations to partial amputations. Simple lacerations are repaired by suture or Dermabond (I have even told family members to use super glue. The bleeding must be stopped. The finger must be cleaned with soap and water. There must not be any tension pulling the edges apart. The glue is used on the surface, never within the cut.) If Dermabond is used, it is best to avoid use of antibiotic ointments as these can “dissolve” the bond before the cut is healed sufficiently. (photo credit)
The question is much more complicated when there is loss of tissue. The main treatment objectives are 1) closure of the wound, 2) maximize sensory return, 3) preserve length, 4) maintain joint function, and 5) achieve a satisfactory cosmetic appearance. How these goals are achieved will depend on the amount of tissue lost, whether there is bone exposed, and which finger is involved. Injuries can be classified according to where the amputation has occurred or whether the injury primarily involves the pulp (soft tissue) or nail bed. These classification systems refer to the zone and the plane of injury.
Zone I is distal to the phalanx (bone)–There is no exposed bone and most of the nail bed is intact which will allow normal nail contours following healing. Treatment of these injuries is usually conservative, especially if the tissue loss is superficial and less than 1 cm square. The wound should then be left open to heal by secondary intention. Meticulous wound care and conservative debridement of these injuries are essential. A dressing of topical antibiotic ointments and non-adherent gauze left alone for several days will facilitate healing. Daily dressing changes can be done after the 4-5th day. As the scar contract, it will give an excellent aesthetic and functional result.
Zone II is distal to the lunula (growth matrix of the nail)–These are complicated by the bony exposure of the distal phalanx. The decision-making process begins with whether length should be preserved (necessitating coverage of the site) or whether sacrifice of length is justifiable in the given situation. The primary aim is to restore function to the individual, and many of these injuries can be converted to wounds with no bone exposed by rongeuring and then closure. If there is no possibility of direct closure, then cover can be accomplished by means of a local flap. The plane (slant of the injury) of zone II injuries helps determine what type of repair technique should be used.
Zone III is proximal to the lunula. –These involve the nail matrix and result in the entire loss of the nail bed. These injuries are most often treated by amputation (revising the end of the traumatic amputation and closing the stump). Replantations distal to the DIP are often not successful.

Methods of ClosureSplit
Thickness Skin Grafts (STSG)–are useful in Zone I injuries that are larger than 1 cm square. It’s advantage over FTSG is that it contracts as it heals and therefore keeps the resultant insensitive area as small as possible. Split-thickness skin from the hypothenar eminence or instep of the foot closely matches the native fingertip skin and is a good choice for the donor skin.
Full Thickness Skin Grafts (FTSG) can be taken from the hypothenar eminence, the lateral groin, the volar wrist crease, or the anti-cubital fossa (inner elbow crease). Some feel that this leaves a less conspicuous donor scar than the STSG.

Flaps are necessary when the loss of fingertip pulp is more than one-third the length of the phalanx. There need to be soft-tissue replacement to support the distal nail. Local flaps include:

Atosoy-Kleinert Flap (photo)
was first described in 1970. It is a triangular volar V-Y flap advancement for reconstruction of the distal pad. It help preserve length when the bone is exposed. It is not indicated in injuries where an oblique flap with more palmar skin loss than dorsal is present.

Kutler Lateral V-Y Flap (photo)
was first described in 1944. It employs two triangular flaps developed from lateral positions and reflected to cover the tip of the digit. This is most applicable to oblique palmar and traverse tip amputations. As the V-shaped skin flap is advanced, an incision line is created which resembles a “Y” when sutured.

Volar Flap Advancement (photo)
is credited to Moberg for coverage of thumb tip amputations. It may also be used for fingertip amputations where length is to be maintained. It provides a sensible covering (has feeling) by advancing volar skin on its neurovascular pedicle. Advancement is limited to 1 cm.

Cross-Finger Pedicle Flap (photo)
was first described by Gurdin and Pangman in 1950. It is useful in distal amputation of the index finger or thumb and in situations where multiple digits are injured and maintenance of length in the remaining injured tips is considered to be of critical importance. Cross finger flap uses skin and subcutaneous tissue from the dorsum of an adjacent finger to cover the fingertip injury. The defect created by “lifting” the flap is covered with a STSG. The pedicle is left attached for 12-14 days and then divided and “tailored” into place.

Thenar Pedicle Flap (photo)
was described in 1926 by Gatewood for coverage of injuries with exposed bone. It was modified by Smith and Albin in 1957 with a technique described as a thenar “H-flap”. The indications are similar to that for a cross-finger pedicle flap (preservation of length, exposed bone). The potential for joint stiffness with a permanent flexion contracture and /or unsightly scar in the donor area must be kept in mind. It is apllicable to injuries in the tips of the index and long fingers, but not the ring or small as the flexion required is not comfortable.Contraindications for use of the cross-finger or thenar flaps would be any general condition that might lead to stiffness (rheumatoid arthritis, Dupuytren’s contracture, etc). There is increased risk of joint stiffness with either flap in someone over 30 years of age.

Replantation of Severed Tip
Replanted single fingers can be stiff and impede the opposition of other fingers to the thumb and overall hand function. Replanted single-finger amputations can achieve better range of motion when the level is distal to the insertion of the flexor digitorum superficialis. Single-finger replantation can be considered when patients have injuries to other fingers of the same hand. All of these injuries require splint immobilization and rehabilitation that impedes immediate return to work. Single-finger replantation can be considered in special circumstances. The surgeon must not become absorbed in the technical challenge of the replantation and neglect the other associated injuries because poorer outcomes and greater financial cost (due to lost wages and cost of hospitalization and therapy) can result.


References
Information & Pictures from Operative Hand Surgery, 2nd Edition, David Green MD, Churchhill Livingstone
Fingertip and Nailbed Injuries by Joseph Donnelly, MD
The V-Y Plasty Technique in Fingertip Amputations by Edward Jackson, MD--American Family Physicians
Fingertip Injuries--Eaton Hand Center
Fingertip Injuries/Amputations--AAOS
Fingertip Injuries by Glen Vaughn--eMedicine article
Assessment & Initial Management of Hand Injuries--Zoltan Hrabovszky
Cohen, B. E., and Cronin, E. D. An innervated cross-finger flap for fingertip reconstruction. Plast. Reconstr. Surg. 72: 688, 1983

7 comments:

Ben Roberts said...

Thanks so much for making this information available. I was unlucky enough to give myself a Zone 1 injury with a table saw this weekend.

While every case is different, the info you have here helps me to understand the nature of the injury I have and what general guidelines are for treatment, so I can discuss with my docs, ask questions and try to make sure the right things are being done.

When something like this happens, even someone like myself who is college educated and has a decent knowledge of biology is at a loss as to what's going on and appropriate treatment paths.

Thanks again for this post.

Anonymous said...

Last week I was leaving the house with my daughter (21 months old) and when I closed the door her finger was still there the doctor said it cut off the tip of her finger but I think it just pulled off the outside of her finger the length is still there and you can still see the shape of the nail in her meat and the nail matrix is still there, do you think she can still grow a nail back?

rlbates said...

Anonymous, with children and what you describe, it may be possible.

Briar said...

The same thing happened ro my son . He slammed the door on gis finger !!
Was devastating .
Amputated his finger right under the nail .i picked up the finger grabed my son and ran to ER. The doctors didnt want to sew in on. Finally they areed to . I hope it heals well- anyone know what the likly prognosis is ? He is almost two yeas old .

rlbates said...

Brair, because of your son's age there is a small chance of the tip surviving.

jt said...

I have a thumb laseration similar to the picture what's the best way to make it look normal agin please help

rlbates said...

JT, you should see your physician.