Principles of radical debridement

The idea of immediate soft tissue coverage requires radical debridement of the wound, changing a dirty wound into a surgical wound. The authors prepare for soft tissue reconstruction much as they do for major replantation, debriding both ends—the part to be replanted and the recipient proximal end—until they find normal tissue. The injured patient who requires soft tissue reconstruction has a better prognosis than a replantation patient, however, because one compartment— volar or dorsal—is frequently spared. Most of the time, the injured upper extremity has some structures that are viable if not intact. They have good innervation and good flow; in many cases, all they need is skeletal stabilization, soft tissue cover, and tendon grafting to make a functional and closed system in one setting.

An example of an extremity with a dirty wound that required radical debridement is shown in Fig. 1. This 27-year-old man sustained a severe road burn to the dorsum of his right hand when

Fig. 1. Road burn injury sustained in the dorsum of the right wrist, which might look simple at first but involves damage and injuries inside the carpus. (Courtesy of The Christine M. Kleinert Institute for Hand and Microsurgery, Inc., Louisville, KY; used with permission.)

Fig. 3. Once all the margins are elevated, it is clear that the wound has been completely excised. (Courtesy of The Christine M. Kleinert Institute for Hand and Microsurgery, Inc., Louisville, KY; used with permission.)

involved in a motor vehicle accident. The wound penetrated the joint capsule, and the patient demonstrated motor deficiency to the wrist extensors and the extensor pollicis longus. Radical deb-ridement was performed starting at the periphery of the wound (Fig. 2). Following the plane of dissection, the wound was elevated from the healthy tissue on top of the deep fascia and excised as an en bloc resection (Fig. 3). Once the debridement was finished, the wound was ready to accept an emergency free flap to provide cover to the repaired extensor tendon and the carpal bone (Fig. 4).

In these cases, there are only three structures that need to be spared. First are nerves in continuity that have the potential to recover. Somewhat less important to maintain is the integrity of tendons and joints. Conversely, a muscle that is severely traumatized certainly fibroses and does not work anymore, and its function is only that of culture media for bacteria. Consequently, it is preferable to excise traumatized muscle until normal anatomy is seen. Proximal muscles that are short and have no means to be connected to tendons are better excised to facilitate wound closure. The idea of this type of debridement is to remove all the dead tissue, heavily contaminated tissue, or tissue so traumatized as not to be of any use. In the words of Marko Godina (personal communication, 1985): ''debridement should be done tumor-like, en bloc wound excision,'' meaning that one should cut through clean tissue and follow the planes of dissections until the wound is excised in total,

Fig. 2. Excision of the wound should start in the normal skin (A) and be elevated tumor-like, en bloc, excising the wound from the skin bed (B). (Courtesy of The Christine M. Kleinert Institute for Hand and Microsurgery, Inc., Louisville, KY; used with permission.)
Fig. 4. Damage to the extensor tendon and carpus can be appreciated. If not detected early, it can lead to septic arthritis. (Courtesy of The Christine M. Kleinert Institute for Hand and Microsurgery, Inc., Louisville, KY; used with permission.)

leaving behind a bed that is ready for immediate coverage.

Techniques

The way the authors have handled these cases is to take aerobic and anaerobic cultures before the wound is prepared and draped. The patient has regional or general anesthesia. The wound is cleansed for no less than 5 minutes, preferably with an iodine solution if the patient is not allergic to it. This shows the stained tissue that needs to be excised. Using only gravity flow, the wound is irrigated with lactated Ringer's solution without pressure, which would further push bacteria into the wound [10]. An Esmarch or Martin's bandage is then applied to exsanguinate the extremity, and a tourniquet is inflated at 100 mm Hg above the patient systolic pressure.

The authors excise the areas that have no normal anatomy and also excise contaminated or contused tissue. Although preserving the vital structures, one must also attempt to eliminate every cavity or dead space. The stages of debridement include identifying the healthy border of the skin, finding a plane of dissection, and excising the wound en bloc.

Once the authors deem the wound to be excised, cultures are taken again from the base of the wound and the tourniquet is released slowly to observe punctate bleeding. If necessary, debridement is continued until every area has good bleeding. The wound is frequently irrigated with bacitracin solution. This manner of radical debridement prepares a bed to accept a free flap immediately.

Emergency free flaps

Emergency free flaps are performed at the end of debridement, within 24 hours of the injury. The superiority of early over late free flap coverage of lower extremity injuries has been shown with unanswerable cogency by Godina [11], with flap failure rates of 0.75% in immediate reconstruction versus 12% in delayed reconstruction and 9.5% in late reconstruction. Total hospital stays averaged 27 days, 130 days, and 256 days, respectively.

The reason for the delay in treatment in the past was a lack of immediate flaps to cover the wounds. Yet, there are circumstances that present clear indications for emergency flaps, including exposed hardware, exposed major vessels, exposed repaired nerves and tendons, open joints, open fractures, and the need for circumferential soft tissue coverage. To be suitable for wound coverage, an emergency free flap must lie over stable bone, have no contamination, and not have any tissue with compromised blood supply.

Primary nerve repair has significant advantages over nerve grafting. Nerve grafting is needed, however, when despite shortening of the extremity, the two nerve ends cannot be coapted. In these cases, the technique of Kanaya and

Proximal Stump Distal Stump

Proximal Stump Distal Stump

Fig. 5. After identifying the motor and sensory fascicles using the Kanaya modification of Karnovsky staining, simply ''connecting the dots,'' motor to motor and sensory to sensory, provides the best possible nerve recovery. (Courtesy of The Christine M. Kleinert Institute for Hand and Microsurgery, Inc., Louisville, KY; used with permission.)

Fig. 5. After identifying the motor and sensory fascicles using the Kanaya modification of Karnovsky staining, simply ''connecting the dots,'' motor to motor and sensory to sensory, provides the best possible nerve recovery. (Courtesy of The Christine M. Kleinert Institute for Hand and Microsurgery, Inc., Louisville, KY; used with permission.)

colleagues [12] helps to identify fascicle patterns to align motor fascicles to motor fascicles and sensory fascicles to sensory fascicles (Fig. 5). If a nerve graft is necessary, the sural nerve offers relatively low donor site morbidity. Nerve grafts may be placed within the flap to maintain blood supply and mobility.

The difference between requiring an emergency free flap and coverage of any defect in the hand by a local flap is the size of the defect. In smaller defects, the authors still use radical debridement and provide immediate coverage with local flaps. Simple skin grafts do not suffice; the bed of the defect does not support them because of the expected function of the underlying structures or in consideration that later reconstruction is likely to make a graft less desirable [5]. In those cases requiring distant flaps, rather than using a pedicle flap, which puts the hand in a dependent position, the authors prefer to create free flaps on an emergency basis. Free flaps are selected over local flaps when a distant flap provides an advantage, such as sensation without the need for cortical reorientation.

An example is the first web space of the foot and toe pulp [13] versus the neurovascular island flap described by Littler [14] for reconstruction of the pulp of the thumb. The same principle applies when other areas of the upper extremity are injured; the shoulder and elbow also suffer if joint movement must be restricted by a pedicle flap and can be rehabilitated more quickly when free flaps are used. Even so, the shoulder, in particular, can benefit from local axial flaps, such as scapula or latissimus dorsi flaps. The elbow can also be covered with pedicled flaps: a radical forearm flap, lateral arm flap, or posterior inteross-eous artery flap. The surgeon should choose the appropriate flap, free or pedicle, for the patient to attain mobility.

In some cases, a major defect requires more filler than just soft tissue cover. In these cases, a muscle flap from a distant donor site is the most appropriate free tissue transfer.

A 44-year-old woman was involved in a rollover accident that caused severe soft tissue injury involving tendon, bone, and loss of musculature of the forearm (Fig. 6) and required revasculariza-tion of the extremity. Radiographs revealed compound open fractures of the radius and ulna with bone loss (Fig. 7). After radical debridement, the radius was fixed with a plate (Fig. 8). The tendons were then tightened to give proper function to the hand. Because of the excess subcutaneous tissue in

Fig. 6. Dorsal and volar aspects of the distal forearm are involved in this complex wound. (Courtesy of The Christine M. Kleinert Institute for Hand and Microsurgery, Inc., Louisville, KY; used with permission.)

this patient, a latissimus dorsi muscle flap rather than a skin flap was used to fill the defect and a skin graft was later applied (Fig. 9). Approximately 4 months after the repair, the patient demonstrated good flexion and extension of the fingers (Fig. 10).

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