Injuries of the hand are common and account for 30% of work-related accidents and also a significant percentage of household and leisure accidents. There are 400,000 people with work-related hand injuries every year in France, but evaluating the total number of hand injuries is more difficult. The figure probably lies around 1.4 million, 620,000 of which are serious and require specialized treatment. The annual cost of this trauma to society is about 1 billion euros.
Too many people with hand injuries neglect misdiagnosed minor injuries based only on the appearance of the skin, or are not examined carefully enough in emergency. This leads to poor primary outcomes and therefore secondary surgery, the results of which are often poorer than those obtained by primary repair.
The clinical examination of an injured hand, although difficult, must be able to detect the following:
major vascular injuries causing devascularization of the tissues;
nerve lesions that are manifest by sensory impairment while motor testing is often impossible due to pain;
tendon injuries that are often obvious for the flexor tendons but more difficult to diagnose for isolated injuries of the extensor apparatus;
It is only after this thorough review that the surgeon is able to establish an operating strategy. The latter has evolved considerably since the introduction of microsurgical techniques, the possibilities of osteosynthesis of fractures and repair of the flexor and extensor tendons, allowing early postoperative mobilization.
Although Iselin advocated the concept of “an emergency with deferred operation” at a time when surgeons had little interest in the hand, this was to determine the limits of necrosis and to allow for the patient to be referred to a competent surgeon. This concept was in 1965 contradicted by J. Gosset and J. Michon, who considered the primary repair of hand injuries kept the patient free of complications, especially edema, compartment syndrome, and infection from necrosed tissue insofar as the debridement was complete.
The appearance of vascular microsurgery has naturally ended these early deliberations. It became clear that restoring circulation saved tissue from necrosis and also facilitated bone and tendon healing, preserving the gliding surfaces, limiting scar sclerosis and promoting nerve regeneration.
This significant technical contribution has naturally made surgical teams dependent on the imperatives related to vascular surgery, in other words, to reestablish the continuity of vessels in an emergency and in any case within the first 6 hours after trauma.
Since 1979, hand emergency services have organized themselves in France and Europe under the acronym CESUM (European Confederation of Hand Emergency Services) and FESUM (European Federation of Hand Emergency Services) to meet these requirements. Experience has shown us that in a “real emergency,” treatment of hand injuries with the contribution of microsurgical techniques significantly shortens the duration of functional disability, reduces secondary effects and reduces reoperation by over 30%. The benefit of such a therapeutic strategy is obvious for the patient as well as for health insurance funds.
This chapter may seem daunting by the descriptive aspect of the different injuries, but it is useful because it is necessary to be specific in injury assessment and to be objective in the therapeutic approach .
In an emergency the surgeon is required to solve three major problems:
stabilize skeletal fractures
revascularize the tissues
ensure skin coverage of tissues
Failing to resolve or simply failing at any one of these three therapeutic levels carries the risk of dangerous complications and haphazard results in secondary surgery.
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.
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.
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.
Evaluating the vitality of the skin covering is always tricky and requires experience. We should be attentive to the same limited bruises that secondarily become deep bedsores. Skin detachment means a rupture of the perforating vascular network, with a risk of subcutaneous hematoma.
When these detachments create reverse (ie, distal pedicle) flaps the proximal third becomes necrotic, so it is preferable to excise it and to rest the remaining skin without creating any tension.
At the end of this examination and elective excision the patient should be free of skin necrosis. If in doubt, it is necessary to consider revising the debridement after 48 hours to allow permanent skin coverage by graft or flap.
Examination of the muscles should be meticulous, in particular for the interosseous muscles, and should begin with dorsal and palmar fasciotomies.
Following crushing, the muscle masses are literally exploded, torn and wine colored. They must undergo a total and uncompromising excision because if dead muscle is left in place it can induce anaerobic septic complications. Fibrosis, a sequela of abandoning devitalized muscle, retracts the intermetacarpal spaces, stiffens the joints and renders secondary surgery by tenolysis, arthrolysis, and nerve and tendon grafts unpredictable, taking into consideration the fibrous environment.
Vascular contusion is often underestimated, and it is through observation of the vessel wall under the microscope that the signs of edema and subadventitial rupture become obvious. Release of the tourniquet after unclogging and cleaning of the vessel lumen makes it possible to test arterial flow. If the latter is not maintained regularly for 30 seconds to a minute, it is because a spasm or subadventitial rupture is situated upstream. In Chapters 8, 15 and 16 , which discuss revascularization and replants, we describe the importance of immediately carrying out arterial grafting if there is any doubt as regards the condition of the vessels.
Evaluating the extent of nerve contusion also requires subtlety. A hematoma traveling under the epineurium is an indication, as is palpation of the nerve. Generally the extent of nerve contusion is underestimated, and it is risky in this case to want to restore continuity after resection in an emergency. In Chapter 14 we specify what to do in this case.
Skeletal Fractures and Joint Injuries
In the case of comminuted fractures an economical approach should be taken; it is sufficient to remove the pulverized bone fragments free from all attachment. In contrast the large fragments are left in place when the tissue environment is of good enough quality for revascularization and bone healing.
Joint injuries or open dislocations should be thoroughly explored, washed and debrided. They can only be closed if the wound has been excised and the skin surface is free from secondary necrosis. It is prudent to ensure a postoperative immobilization, depending on the position of the joint injuries.
Tendons and Their Sheaths
When opening flexor tendon sheaths, it is necessary to trim and wash the remaining sheath with an antibiotic solution. The contusion of tendons is often evident, and the extent of their excision depends on whether primary or secondary repair is to be done.
After this surgical examination the wound, explored in its entirety, will be extensively washed with saline. The tourniquet is then released, and compression ensures hemostasis during the vasodilatation phase. The latter can be completed by bipolar coagulation of the vessels that do not require microsurgical repair.