Wednesday, October 29, 2008

Soft-Tissue Injuries of the Fingertip

As we get closer to Halloween and in light of my post on preventing injuries when carving those pumpkins, I thought I would review injuries to the fingertip.  This post is a reworking of the post a did on fingertip injuries/amputations more than a year ago.  In this post, I’m going to stick to injuries of the fingertip.  (photo credit)

 

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. 

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

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.   It may also depend on the patient’s profession or hobbies (ie professional musician who may not tolerate decreased sensitivity to his long finger whereas a truck driver might not notice it). 

 

Injuries may also 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 (photo credit) 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

Soft-Tissue Injuries of the Fingertip: Methods of Evaluation and Treatment. An Algorithmic Approach; Plast. Reconstr. Surg. 122: 105e, 2008; Lemmon, J. A.,  Janis, J. E., Rohrich, R. J.

Nail Lengthening and Fingertip Amputations;  Plast. Reconstr. Surg. 112: 1287, 2003; Adani, R., Marcoccio, I., and Tarallo, L.

11 comments:

mark's tails said...

Yes, well it is a good thing I wasn't eating when I saw this post ;)

DrCris said...

Amazing post, Ramona. I have printed this one to use when I am studying and for future reference.

I had not seen some of those flaps before. I was particuarly impressed with Atosoy-Kleinert, which seems very useful.

rlbates said...

Thanks, Dr Cris. Glad you found it useful.

Sorry, Mark. I often forget that others find this stuff gross.

Øystein said...

Excellent article!

I was especially fascinated by the Thenar pedicle flap. Do you know if it's a much used technique?

Which book are the illustrations from?

rlbates said...

Oystein, thanks. The thenar pedicle flap is often used by hand surgeons.

The illustrations are from the first reference (Operative Hand Surgery, 2nd Edition, David Green MD, Churchhill Livingstone).

Bongi said...

i had a patient today with dogbite and loss of entire pulp spase. i turfed to ortho. naughty me.

Buckeye Surgeon said...

great post. I drain felons and that's about it. The hand makes me nervous...

James Hubbard, M.D., M.P.H. said...

Thanks for the helpful information

j anthony z said...

I suffered a nail bed avulson w/multiple fractures 5 days ago at work w/DSNY. Found your blog and links very informative
Thanks
jz

Cbarba said...

Thanks for the helpful info, yesterday, I cut the tip of my finger and the ER doctor closed it with dermabond. In my opinion he did a very sloppy job and did not pinch the wound all the way closed before applying the dermabond. Lat night a small amount of blood came through , but it is not currently bleeding. Should I have any concern?
Thanks!
Christina

rlbates said...

Christina, just protect it with a waterproof bandaid for a few days.