The Mangled Hand



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



Physical Examination

May 7, 2019 | Posted by in ORTHOPEDIC | Comments Off on The Mangled Hand
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