Lacerations to the hand are very common injuries which account for 10-20% of emergency room visits.1 Lacerations can be superficial or deep. Superficial lacerations cut the epidermis and dermis if they are full thickness lacerations. Deep lacerations cut into the subcutaneous tissues. Whether a broken piece of glass or a knife passed through the subcutaneous tissue to damage underlying structures at risk can be difficult to assess. This can be particularly difficult with an uncooperative patient or a terrified child with a bleeding hand.
Despite the emergent nature of the injury, a careful examination is necessary in order to evaluate the underlying structures. One-half of the lacerations that occur in the hand and wrist and enter the subcutaneous tissues cause damage to the underlying structures.2,3 When a laceration enters the subcutaneous tissue, then the deeper structures at risk can be damaged. As a knife, for example, passes through the subcutaneous tissues, the Structures At Risk include:
- Cutaneous nerves like the dorsal radial sensory nerve
- Extensor and flexor tendons
- Major nerves like the median nerve, ulnar nerve, common digital nerve and digital nerve
- Bone – a circular saw can easily lacerate the skin; subcutaneous tissues; extensor tendons and fracture the underlying bone
- Joint – depending on the exact location of the laceration, the knife may cut the joint capsule, injure joint cartilage or ligaments and contaminate the joint space
- Arteries and veins – depending on location of injury, the radial artery, the ulnar artery or a major vein like the cephalic vein can be transected during a wrist laceration.2,3
Untidy wounds that have a crush or skin avulsion component are even more likely to be associated with damage to the deeper structures.
Related Anatomy
- Skin
- Subcutaneous tissue
- Other related anatomic structures will depend on the depth of the wound. Theoretically, any digit, hand, wrist or forearm structure can be at risk for injury secondary to a deep laceration.
Incidence and Related Conditions
Incidence: The incidence of hand, wrist and forearm injuries presenting to the emergency room is substantial. Nascab and his authors’ review found rates of hand injuries between 6.6% and 21% of injuries presenting to the emergency department occurred in the hand.2 Glass and knife injuries account for the majority of the hand lacerations.3 Sixty percent of these lacerations had at least one deeper structure cut and 15% of the lacerations had combined injuries involving arteries, nerves and/or tendons.
Related injuries include amputations, partial amputations, crush injuries, avulsion injuries and burns.
Differential Diagnosis
None
