Injury Assessment and Operative Strategy

Classification of Hand Injuries

The variety of hand trauma makes it difficult to establish a classification that is both comprehensive and easy to use. However, it is easy to separate lacerations from crush injuries.

Lacerations, usually caused by bites or cuts, must be classified into two categories:

• simple wounds that affect only the skin

• complex wounds that combine skin injuries with damage to the skeletal, neurovascular and muscle-tendon structures

A puncture wound can cause injuries at multiple levels.

Crush injuries may also involve avulsions or shredding and more frequently arise in an artisanal or industrial context.

The examination specifies the time and mechanism of injury, as well as the amount of contamination, which will be major after an animal or human bite and contraindicates primary closure. Similarly, plant wounds may be the source of septic complications.

Some trauma induces specific injuries that require appropriate treatment. This is the case for wounds caused by firearms, explosions, pressure injection, crush-burns, roller injuries, presses, degloving, and others.

Initial Examination of the Injured Hand

The injured patient must undergo a clinical examination before any anesthesia or setting up any tourniquet. The examination is performed in a dressing room with the patient lying down. The dressing is removed after wetting of the hand.

The appearance of the injuries indicates whether the patient suffers from a laceration or a form of crush injury.

The examination should be conducted with patience and by asking the patient to reproduce gestures made by the intact hand. This motor examination is not always easy to perform because of the pain and skeletal injuries.

The sensory examination is more conclusive, and the two-point discrimination test can usually assess the condition of the peripheral nervous system.

The vascular status of the hand is assessed by the speed of nail-bed recoloring and by the filling of the digital pulp after compression. Complete devascularization is usually obvious; however, when it is partial, the Allen test performed at the wrist is used to find the respective contribution of the radial and ulnar arteries.

Clinical evaluation of tissues after a crush injury is more difficult; it is only during surgical exploration that the vitality of tissues can be evaluated. The experience of the surgeon is important here because overestimation of tissue vitality inevitably leads to necrosis and infection, weighing heavily on functional outcome.

At the end of this first clinical examination it is important to tactfully and psychologically explain to the patient the nature of the apparent injuries, pointing out that surgical exploration will refine the diagnosis. At this stage it is also possible to explain the surgical strategy to the patient. In the event of it being impossible to conserve one or more fingers, it should be noted that amputation may be temporary and that the hand will benefit from a secondary reconstruction by toe transfer, pollicization, elongation or other procedure.

The patient must, through this interview, understand that although the surgical team has a coherent treatment plan, his or her postoperative participation will be a key element in successful functional and psychological rehabilitation.

Preparation

After anesthesia of the limb (usually by axillary block) and placement of the tourniquet, which will be inflated without the use of an Esmarch tourniquet but simply by raising the limb, the wound is brushed to remove any contaminants, then thoroughly washed with saline, avoiding any antiseptic that affects the vessels and nerves ( Fig. 4.1 ). This should be performed by the surgeon because it allows him or her to assess the tissues, the degree of contusion and any contamination.

Surgical Exploration

The tissues are explored one level at a time by raising the skin and fascia to identify all injuries and nonviable tissue.

Crush injuries may take many forms depending on the nature of the affected tissue and trauma. Injury may be limited to simple attrition of the skin edges but can also be the result of extensive crushing, an avulsion or a detachment, which also leads to tissue necrosis.

Tissues must be assessed on their appearance, texture and elasticity to proceed with certainty to debridement. English speakers use the term debridement, whereas Michon preferred the term elective excision. The purpose of such an exploration is to make the wound aseptic by eliminating foreign bodies and devitalized tissues. The risk is limiting this elective excision and covering an area destined for necrosis, which often leads to infection.