Hand injuries continue to be problems that are frequently seen in emergency departments (EDs) around the world. In the U.S., amputations involving the hand are very common in both the work environment1and in the home.2 Amputations can be partial or complete, with partial hand amputations being the most frequently seen work-related amputation in the world.3,4 Most work-related amputations occur in young males (>80%) with limited education beyond high school,1 during the regular work week, while using machines such as saws, punch presses, food and beverage machines, and printing presses.2,5 The industries where amputations are most common include agriculture, forestry, fishing, manufacturing, and construction.1 In many cases, machinery guards and shields are not used by the workers who injure themselves. Other causes of hand amputations include malignancy, disease, and congenital anomalies.4 Regardless of the cause, these injuries typically cause permanent disability, psychological distress, and loss of work to the individual, which has both direct and indirect implications on each patient and society as a whole.3,4
Definitions
A hand amputation is the loss of any part the hand distal to the carpal bones.1,4 The hand amputation can be partial or complete.2 With a partial amputation, there may be a skin bridge still connecting the distal part of the hand to the stump. In complete amputations, there is no visible connection between the amputated part of the hand and the stump. Amputations may also be defined by the level of the transection, depending on which bone or joint of the hand the amputation crosses through.
Related Anatomy
Obviously, complete amputation of the hand involves all the tissues in the amputated part. Therefore, a hand amputation involves the skin, veins, extensor tendons, bone, flexor tendons, digital nerves, and digital arteries.
|
|
Amputation
|
Replant
|
| Bone |
- Shorten bone to allow for good soft tissue coverage of bone end
|
- Debride bone ends and shorten proximal and/or distal to remove tension on microsurgical repairs.
- Do some type of ORIF for the bone, often multiple K-wire fixation
|
| Flexor tendons |
- Debride and allow ends to retract
- Do not suture tendon over the end of bony stump
|
|
| Extensor tendons |
|
- Repair the extensor tendon
|
| Digital arteries |
- Cauterize common digital arteries at the stump level. If ulnar and/or radial artery is cut, then these arteries should be ligated.
- Microsurgical repair
|
|
| Digital nerves |
- Pull common digital nerve endings distally, cut sharply and allow ends to retract in surrounding soft tissue. If the amputation is at the wrist level, then the cut nerves can be the median nerve, ulnar nerve and/or radial sensory nerve
- Microsurgical repair
|
|
| Veins |
- Cauterize veins on the stump
|
|
| Skin |
- Maintain healthy viable skin for stump coverage
|
- Maintain healthy viable skin for coverage of the circumferential wound
|
- One classification system for partial hand amputations places injuries into one of the following four groups:
- 1) Transphalangeal: involves one or more fingers at or just distal to the metacarpophalangeal (MP) joint; the thumb is spared
- 2) Thenar: involves the thumb; can be partial or complete
- 3) Transmetacarpal distal: an amputation across the palm; the thumb may or may not be involved
- 4) Transmetacarpal proximal: an amputation across the proximal section of the metacarpals near the carpus; involves the thumb4
Overall Incidence
- Conn and colleagues reported that there are >30,000 non-work-related finger amputations annually in the U.S.2 They also identified two high-risk groups: children aged <5 years and adults, usually males, aged >55 years.
- Children often get a finger or hand shut in a door, and adults are usually injured by power saws, snow blowers, and other machinery.
- Amputations were also found to occur secondary to a cut, crush, bite, or burn.
- Factors such as alcohol use, fatigue, decreased dexterity, and reflex time and medication use were cited as frequent secondary causes associated with these injuries.
- Another study used 3 years of data from the National Inpatient Sample of the Healthcare Cost and Utilization Project to identify 9,407 upper extremity amputations.6
- Of these amputations, 6,891 involved the fingers, 1,947 involved the thumb, and 840 involved complete hands or arms.6
- Approximately 15% of these amputations underwent replantation, including 27% of patients with a thumb amputation. The mean cost of replantation was >$40,000.
- In the U.S., amputations are very common in the workplace:
- Amputation rates vary from 1.5-3.7 per 10,000 full-time workers per year.1
- Single digit amputations occur 81% of the time, and multiple digital amputations in 14%.1
- In North Carolina between 2004-2006, the amputation rate was 21.3 amputations per one million people. There was no correlation to increased numbers of immigrants.5
- One study found that 68-78% of total trauma amputations involve the upper extremities, and ~90% of these are partial hand amputations.4
- The estimated annual incidence of partial hand amputations in the U.S. is 1 in 18,000 persons.4
Related Injuries/Conditions
- The majority of upper extremity amputations are secondary to traumatic injuries; however, amputations are also performed surgically to treat severe burns, neoplasms, vascular peripheral disease, nerve damage, and uncontrollable chronic infections.4
- Congenital amputations are very rare: the Centers for Disease Control and Prevention estimates 4/10,000 babies are born with upper limb reductions.8
Differential Diagnosis
- Traumatic amputation
- Surgical amputation for tumor or infection control
- Congenital amputation
