The Mangled Hand
Jason S. Lipof
John C. Elfar
INTRODUCTION
The mangled extremity, by definition, exhibits injury to three or more of the four limb systems: (1) soft tissue, (2) nerves, (3) vessels, and (4) bone (Figure 55.1).
It is marked by significant tissue damage and loss, these injuries are physically and psychologically devastating.
Del Piñal’s “acceptable hand” concept is defined as a hand with three fingers of near-normal length, near-normal proximal interphalangeal (PIP) joint motion, good sensibility, and a functional thumb. This may be helpful in determining a surgical plan for reconstruction.
Due to modern advances in surgical reconstruction, limb salvage, nerve repair and transfer, internal fixation capabilities, soft-tissue handling and transfer, and microvascular reconstruction, injuries previously treated with amputation are now salvaged.
The decision to attempt salvage of a mangled extremity is complex and involves the surgeon, patient, their support system, and resources available.
Surgical salvage of a mangled limb is often time and resource consuming for the surgeon and patient, plagued by reoperations, complications, infection, pain, and morbidity.
The ability to manage a mangled limb is often based on the state of the remaining tissues.
Mechanism and severity of injury, the initial operative assessment and debridement, reconstruction, patient compliance, and their involvement in rehabilitation have a direct impact on outcome.
 FIGURE 55.1 A 35-year-old male status-post table saw injury to his right palm. Despite soft-tissue attachments, all flexors, digital nerves, and digital arteries to the lesser four digits were severed. Emergent revascularization, nerve, and tendon repair were undertaken. |
Mechanism
Often caused by industrial or agricultural equipment, explosion, power tool injury, motor vehicle accidents, and high-velocity firearms.
Higher energy → increased four-system tissue-type damage → decreased viability and vascularity of tissues → increased risk of infection and poor outcome.
Typically, these injuries involve a significant crush component and may also exhibit degloving, avulsion, friction burn, abrasion, and partial amputation.
Mangling injuries are often severely contaminated, especially those caused by farming and industrial equipment.
For severely contaminated limbs, serial and extensive irrigation and debridement are necessary, as well as appropriate antibiotic selection.
Pathoanatomy and Pathophysiology
Crush, explosion, and destruction of soft tissues cause endothelial injury, devascularization, and direct cell disruption. Resultant ischemia,
depletion of oxygen, ATP, and glucose in turn cause increased CO2 and lactic acid to accumulate. These increase superoxide free radicals and begin a cascade of chemotaxis causing local inflammation, increased endothelial injury, worsening microvascular flow, and eventually necrosis.
Direct crush injury affects tissues differently. From most to least severe, tissues affected include skin > muscle > fat > vessels > nerve.
Tendon, ligament, and bone are relatively crush resistant, depending on mechanism and force of crush.
Reperfusion injury is caused by two mechanisms: (1) superoxide radicals interact with endothelial membranes, causing lipid peroxidation, increased permeability of endothelium, and edema. (2) Chemotaxis causes polymorphonuclear infiltration of tissues which causes microvascular occlusion, local tissue destruction, and necrosis. The latter mechanism is typically responsible for the characteristic “zone of injury” associated with these injuries.
EVALUATION
History
Key questions include:
Is this an agricultural injury? Does it involve caustic substances? Is there significant contamination? Is the injury work-related?
This information may direct antibiotic choices, decision for acute versus delayed closure, and nature and extent of debridement.
Timing of injury:
Important to discern warm or cold ischemia time for dysvascular tissue.
Increased time from injury to operation is associated with increased infection rate and poor outcome.
Mechanism:
May help elucidate extent of energy imparted to soft tissues
Can define zone of injury
Past medical history:
Important information includes: age, hand dominance, cardiac and vascular comorbidities, and diabetes.
Prior surgeries and injuries to affected extremity
Medication list and allergies
Social history:
History of smoking, alcohol, substance use
Patient occupation
Support system/living situation
Ability to comply with postoperative rehabilitation
Physical Examination
Due to the extensive and usually very painful nature of these injuries, it is often impossible to fully evaluate a mangled extremity in the emergency room, and injuries are most thoroughly assessed under anesthesia in the operating room.
Emergency room evaluation:
It is important to obtain a brief examination to assess the four systems—soft tissue, nerves, vessels, and bone (Figure 55.1)Related posts:
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