CASE                               47                               

The patient is a 74-year-old man involved in a motor vehicle collision who sustained a soft tissue injury to the dorsum of his left hand when it was caught out the window (Fig. 4–23). He has no other injuries and is otherwise healthy. He

underwent initial debridement followed by extensor tendon repair (extensor digitorum communis to the index and middle fingers as well as the extensor indicis proprius) and is left with an 8 × 8 cm wound over the dorsum of the hand, with exposed extensor tendons.

Figure 4–23

Which of the following will have the greatest impact on the likely take of skin graft reconstruction of this wound?

1. The presence of underlying fractures

2. The smoking status of the patient

3. Whether or not the skin graft is meshed

4. The presence of intact paratenon coverage of the tendons

5. None of these factors will have an impact

Discussion

The correct answer is (D). Skin grafting is often a viable option for reconstruction in the extremity. In order to obtain predictable success with skin grafting along tendon surfaces, the most important component is the presence of intact paratenon, which will allow take of the skin graft because of its vascularity. The other factors will also contribute to the overall success rate, but the graft will not survive if it is placed over a traumatized, avascular bed.

Given the patient’s exposed critical structures, more robust soft tissue coverage is warranted, and a reverse radial forearm flap is chosen.

Which of the following is NOT TRUE about this flap?

1. Perfusion through the ulnar artery into the hand must be intact to use this flap for reconstruction

2. This flap is distally based, with arterial inflow through the distal aspect of the radial artery

3. There is no need for venous drainage for this flap, since venous flow would be against the direction of the valvular system

4. This flap can be included as a “fascia-only” flap or a fasciocutaneous flap (with a skin paddle)

5. This flap is capable of resurfacing the entire dorsum of the hand and allows for adequate tendon gliding

Discussion

The correct answer is (C). The reverse radial forearm flap is a conventional reconstructive option for dorsal hand wounds, and is capable of resurfacing the entire dorsum of the hand. It can be used as a “fascia-only” or a “fasciocutaneous” flap. In order to use this flap, perfusion through the ulnar artery must be intact. Importantly, this flap has a reliable arterial supply with a robust venous drainage system; despite the presence of unidirectional valves it appears that denervation, vascular engorgement, and elevated venous pressure contribute to the ability to drain the flap in retrograde fashion.

In patients who cannot undergo a reverse radial forearm flap, what other options for soft tissue coverage are available?

1. Posterior interosseous artery flap

2. Integra® placement followed by skin graft coverage in 2 to 4 weeks

3. Free flap coverage using an anterolateral thigh flap

4. A and C

5. All of the above

Discussion

The correct answer is (E). There are many options for soft tissue coverage of the dorsum of the hand. In addition to the reverse radial forearm flap, coverage with a posterior interosseous artery flap or a free flap, such as the anterolateral thigh flap, is commonly utilized. In addition to autologous options, Integra® and other skin substitutes can be used as a bridge to skin grafting such difficult wounds; Integra has been shown to have >90% success over exposed tendons, although the resultant gliding of these structures has not been well studied.

Objectives: Did you learn...?

Access the risk factors for poor outcomes of skin grafting? Describe the characteristics of a reverse radial forearm flap?