Management of mangled extremities

Indications for reconstruction

• The word mangled derives from a French word meaning “cut to pieces,” or a Latin word for to “cut or lop off.” Mangled extremities are typically defined as the result of a traumatic injury that harms three or more structures. Crush, avulsion, and blast injuries are common causes of mangled upper extremities.

• It is often preferable to save a hand with rudimentary function rather than perform an amputation. Although more sophisticated prostheses are in development, commercially available options do not provide the sensory feedback that is vital for hand function. Instead, the patient must watch the hand in space and practice extensively to modulate the precise force needed to manipulate objects.

• A clear discussion with the patient and family members is essential so that everyone recognizes the potential outcomes and need for extensive rehabilitation. It is also important to understand the patient’s goals and expectations, social support, and occupation when deciding which procedures to perform. For example, farmers may want to return to work sooner, so a more limited reconstruction with decreased disability time would be ideal.

• Reconstruction should always be attempted in children because they have a great capacity for healing and recovery of nerve function.

• Surgeon skill is the major determinant of outcomes. The surgeon must be well versed in reconstruction of all injured structures, including bone, tendons, nerves, vessels, and soft tissue coverage, before undertaking complex reconstruction of mangled extremities.

Indications for amputation

• Although most hand and upper limb injuries can be saved, amputation is a form of reconstruction as well (see Chapter 4 Proximal Upper Extremity Amputation).

• It is important to put forth the caveat of life before limb; if the patient has life-threatening injuries in addition to a mangled extremity, it is sensible to perform a guillotine amputation to save the patient’s life and prevent ongoing blood loss as more urgent needs are being addressed.

• Amputation is also indicated if there is severe contamination or if the patient has significant comorbid conditions. For example, underlying obstructive vascular conditions may be exacerbated if dramatic fluid shifts take place during reconstruction.

• Multiple complex surgical procedures may not be desired or suitable for patients with advanced age or mental disorders because of the need for multiple operations and extensive rehabilitation. Therefore communication with the patient to reach a consensus on future goals is essential when deciding to pursue complex procedures versus amputation.

Patient history

• Obtain the mechanism of injury from the patient or bystanders to determine the amount of energy that was imparted through the tissues and the potential for contamination. This will inform the urgency and organization of treatment.

  • High-energy injuries, such as those caused by industrial or farming accidents, often cause tremendous tissue damage throughout the hand. There is also a risk for contamination if the tissues are embedded with soil or other bacteria-laden material. The debris within the wound will cause infection unless radical debridement and early cleaning are carried out to prevent seeding throughout the hand.

  • Severe crush injuries ( Fig. 85.1 ) cause obvious bruising and often damage the underlying muscles. As a result, the muscles swell in the unyielding fascia and cause compartment syndrome and skeletal, nerve, and vascular injuries.

    

  • Motor vehicle accidents may overtake industrial accidents as the major cause of mangled extremities in more developed areas of the world.

  • Large caliber projectile and blast mechanisms are a common cause of mangled extremities in many areas of conflict around the world. In the United States, civilian gun injuries are not uncommon from hunting accidents or personal assault.

• Determine whether the patient has any vascular, pulmonary, or cardiac conditions.

• Gather information about the patient’s social history, including smoking status (greater risk for wound complications and vascular problems) and occupation, as well as hand dominance.

Clinical examination

• Mangled extremities can detract attention from more life-threatening injuries. Thus it is important to strip the patient naked and evaluate the entire body for further damage.

• Trauma assessment is critical because intraabdominal injuries can be devastating to the well-being of the patient. Remember the primary survey of ABCs: assess the airway, breathing, and circulation.

• Contamination in the hand may spread throughout the upper extremity and to other parts of the body. Thoroughly evaluate the extent of damage and coordinate with the trauma team to ensure that all injured and contaminated tissues are accounted for in the treatment plan.

• Perform a hand evaluation if the patient is conscious. An understanding of the vascularity, sensation, and function of the distal hand and fingers, as well as the level of injury, is necessary to determine the operative needs based on what tissues were lost and which structures are still present.

• One should not probe the wound to determine the type of injuries that are present and structures that are damaged. A coherent hand examination should give the surgeon an excellent catalog of structures that are intact or lost.

Reconstructive priorities

• The American Medical Association (AMA) established an impairment rating system to gauge the functional loss associated with digit or extremity amputation ( Table 85.1 ).

  TABLE 85.1

  Estimated Percentage of the Effect of an Upper Extremity Impairment on Activities of Daily Living

  (Data from Cocchiarella L, Andersson GBJ, eds. AMA Guidelines of Permanent Impairment. 5th ed. American Medical Association; 2001.)

  	% Impairment
  	Amputation hand	Upper extremity	Whole body
  Index or long finger	20	18	11
  Ring or little finger	10	9	5
  Thumb	40–50	36–45	22–27
  Hand	__	90	54
  Upper extremity	__	__	60

• It is important to keep in mind that impairment indicates a loss of structure but not necessary a loss of function, whereas disability describes a loss of function or an inability to cope with the impairment.

• As noted in Table 85.1 , the thumb accounts for 40% to 50% of hand function and is therefore a reconstructive priority.

• It is essential to reconstruct the thumb with one, or ideally two, opposable digits so that the patient can perform tripod pinch. If possible, save the ring and little finger to restore power grip function.

• It is unreliable to use a numerical severity score to predict mangled upper extremity reconstruction outcomes because of the varied injury patterns and reconstruction options.

Early management of ischemia and bleeding

• Keep track of the time since injury. Greater than 6 hours of warm ischemia leads to muscle death. If the limb is devascularized, establish vascular flow in the arm using vein grafts or a temporary vascular shunt so that the limb can be perfused while more urgent needs are being addressed.

• If ischemia lasts more than 6 hours, then perform a mandatory prophylactic fasciotomy (see Chapter 2 Fasciotomy for Compartment Syndrome of the Hand and Forearm) of the upper arm if necessary, the forearm, and the hand compartments. Otherwise, swelling of the muscles in the tight fascia compartments will restrict blood flow to the muscles and tissues, particularly when the arm is reperfused after revascularization.

• Stop all severe bleeding as soon as possible by placing direct pressure over the bleeding site. In most cases, local pressure suffices until the patient is adequately resuscitated with fluids and/or blood products.

• If the bleeding is not controlled with local pressure, then place a bulky dressing over the open wound to tamponade the bleeding vessel.

• Bleeding sources are most often partially cut vessels that cannot retract and seal off the blood flow. If the arterial bleed is identified, it is prudent to carefully ligate the arterial source under a good light source.

Operative strategies

The general operative strategies are explained in the following sections and then two cases are presented to convey the key points of mangled upper extremity management.