Monday, December 6, 2010

Dorsal Hand Coverage Refinements

Injuries to the dorsal hand, wrist, and distal forearm are relatively common. Degloving and crush injuries can result in exposed tendons and bone. These are not simple wounds which can be repaired by primary closure but often require early debridement of devitalized tissue and soft-tissue coverage involving local or regional flaps (reverse radial/ulnar forearm or posterior interosseus flaps), distant pedicle flaps, or free flaps.

The skin of dorsal hand and wrist is very thin, mobile, and supple and very visible in day to day activities. We present our hand in greeting for a hand shake. Our hands are visible when keyboarding or talking on the phone. We hold hands with our loved ones. We want our hands to both work/function and be aesthetically pleasing.

Function must come first with a severe injury, but the authors of the first article referenced below correctly note “with high success rates, flap survival should no longer be the sole criterion in judging success in dorsal hand and wrist reconstruction.”

In an attempt to determine the best flap for dorsal hand coverage in terms of aesthetic appearance, donor-site morbidity, and minimization of revision surgery, the authors conducted a retrospective review of all free flaps for dorsal hand and wrist coverage from 2002 to 2008 was performed. Flaps were divided into four groups: muscle, fasciocutaneous, fascial, and venous flaps. Outcomes assessed included need for debulking, blinded grading of aesthetic outcomes, and flap and donor-site complications.

The problem with this article and it’s outcomes is the fact that it is a retrospective review. This “confounding factor” is expounded upon in the discussion article (second reference below).

Keeping that in mind, here are a few “findings”

Fasciocutaneous flaps scored the lowest in all aesthetic categories. The bulkiness of these flaps can make contouring difficult and often require future debulking. Color match is also an aesthetic issue.

Fasciocutaneous flap donor-sites often require skin grafting. When primary closure is done, the authors found a higher rate of breakdown than with the other flaps.

Due to these disadvantages, fasciocutaneous flaps have become our secondary choice for dorsal hand reconstruction.

There are two advantages of fasciocutaneous flaps. First, flap re-elevation is easier than with muscle flaps.

Second, flap tissue can be rearranged and divided with less concern for blood supply as would be needed in a muscle flap; a few months after flap transfer, fasciocutaneous flaps appear to be less reliant on the primary pedicle. In addition, if patients will require secondary reconstructions, then debulking can be done at this time.

The authors found muscle flaps covered with split-thickness skin grafts had significantly better overall aesthetic, contour, and color match results than fasciocutaneous flaps. They also required less debulking most likely due to atrophy of the muscle.

We have been increasingly using partial muscle flaps for dorsal hand and wrist coverage in which the flap size harvested is tailored to the defect size. These are harvested as a partial superior latissimus muscle or as a partial medial rectus muscle flap, leaving the majority of the donor muscle and its motor nerve intact. These are small, custom-designed flaps.

………Despite the teaching that fascia is needed for tendon glide, we have noted no difference in tendon functional results when covered with muscle versus fascia. This conceptually makes sense, as normally tendons and muscle bellies constantly glide past each other in the forearm.

Fascial flaps with split-thickness skin graft are thin and pliable. These scored high in all aesthetic categories and rarely needed debulking. Donor-site morbidity is minimal, as no muscle is harvested and the donor site is closed primarily without need for grafting.

For these reasons, fascial flaps are a first-line treatment for moderate-sized to large dorsal hand wounds, allowing a single-staged procedure with minimal need for revision surgery. Their aesthetic appearance is better than that of fasciocutaneous flaps, and they require less debulking than muscle flaps.

Final aesthetic results are dependent on skin graft take and any graft failure results in poorer texture and color match results. Nonmeshed grafts have better aesthetic results than meshed grafts for the dorsal hand.

Venous flaps required no debulking in this study and had the best overall aesthetic results with excellent color, contour, and texture match. These flaps are often harvested from the volar forearm in the suprafascial plane, allowing them to be very thin and pliable, matching the surrounding dorsal hand skin. They are limited to use for small to moderate-sized defects.

REFERENCE

Refining Outcomes in Dorsal Hand Coverage: Consideration of Aesthetics and Donor-Site Morbidity; Parrett, Brian M.; Bou-Merhi, Joseph S.; Buntic, R. F.; Safa, B.; Buncke, G. M.; Brooks, D.; Plastic & Reconstructive Surgery. 126(5):1630-1638, November 2010; doi: 10.1097/PRS.0b013e3181ef8ea3

Discussion: Refining Outcomes in Dorsal Hand Coverage: Consideration of Aesthetics and Donor-Site Morbidity; Fang, F.; Song, J. W.; Chung, K. C.; Plastic & Reconstructive Surgery. 126(5):1639-1641, Nov 2010; doi: 10.1097/PRS.0b013e3181f1cf42

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