Digital amputation is often associated with traumatic injuries but is also seen within the elective surgery setting, such as cancer resection and management of chronic conditions such as Dupuytrens contractures or peripheral vascular disease. It is also seen as a consequence of severe sepsis, although this often results in auto-amputation.
In the traumatic setting, the primary objective of management is to salvage the amputated finger to restore function, especially if the dominant hand is affected. However, this is not always possible, as there are many factors to consider. These factors include the time from injury, mechanism of injury, and degree of contamination . In the elective setting, determinants for the level of amputation include various factors, such as oncological clearance, symptom relief, and function preservation; however, for the purpose of this paper, the primary focus will be on a traumatic finger amputation.
The basic goal in the treatment of digit amputations (especially upper limb) includes
In traumatic injuries, one should assess the patient in accordance with the advanced trauma life support approach (airway, breathing, circulation, etc.) for a systematic assessment of the patient and to rule out any life-threatening injuries before referring or transferring patients for further specialist management of their finger injuries. Determining the mechanism of injury is crucial, as it could affect decisions regarding management and outcome for the patient. Sharp injuries may provide a clear amputation level, whereas blunt trauma may correlate with crush injuries at the level of the amputation, and avulsion injuries can cause distant trauma away from the level of visible injury.
Amputation injuries represent approximately 1% of all trauma-related injuries presenting to the emergency department, with finger and thumb amputations being the most common. Fingertip and partial digit amputation are the most frequent presentations, complete digit and multiple digit amputations are less common, with most injuries occurring at home. Its incidence is higher in adults (men greater than women, approximately 4 to 1) than children (approximately 3 to 1 adult to child ratio). Working with power tools is the most common cause of injury in adults.
Typically, once a finger amputation has occurred, ischemic tolerance times are 12 hours if warm and up to 24 hours if cold. For more proximal amputations, these times are halved. The amputated part should be covered in a normal saline-soaked gauze, sealed in a plastic bag and submerged in icy water with no direct contact with ice. If there is direct contact with ice, it could result in tissue damage and render the amputated part non-viable. More proximal amputations are less tolerant of ischemia due to the presence of muscle tissue, which can undergo irreversible changes after 6 hours of ischemia.
The important aspects to be noted in history are hand dominance, occupation, time of injury, mechanism of injury, other associated injuries, comorbidities, and NPO status.
Level of amputation, structures involved, neurovascular status, function, and degree of contamination (if relevant). It is vital to assess the amputated part and ultimately determine its suitability for replanting respective to the mechanism of injury (e.g., crush, guillotine-style, avulsion).
Finger amputations classification is generally according to the level of amputation. The Sebastian and Chung classification is outlined below:
Laboratory:(optional depending on the clinical scenario)
CBC (complete blood count) to assess for blood loss
Coagulation studies (only if the patient is known to be on anticoagulants)
Plain radiograph of the affected finger/hand and amputated part; this allows assessment of bony injuries, bone quality, and guide decisions regarding bony fixation methods. Angiograms are normally not requested unless it forms part of investigations for other injuries.
Initial management - first aid, ATLS approach to the patient, preserve amputated part, tetanus vaccination, and antibiotics as per local hospital guidelines.
In the traumatic setting, the ideal candidate for replantation should be young, healthy, sharp mechanism of injury (giving a clear amputation level), minimal tissue destruction, and contamination.
Contraindications and relative contraindications:
Once the patient arrives in the operating theater, the amputated part should undergo a careful assessment for suitability for replanting. All structures should be dissected and identified, especially the neurovascular bundle. If no suitable vessels are identified, then replantation should not proceed. Usually, there is an order for repair of structures:
Bone fixation should be simple and quick to perform, but it also depends on the configuration of bony injuries. Usually, two Kirschner wires are an option, but other fixation methods may also be used (i.e., plate fixation). Occasionally, bone shortening is required before fixation to allow for soft tissue closure and repair of neurovascular structures without excessive tension.
In case the restoration is not possible, and the clinician decides to opt for amputating or forming a stump, then provide a mobile, stable, painless stump with the least interference from the remaining tendon and joint function to ensure the most useful result. Whenever possible, use volar skin for the stump coverage because it provides skin that is thicker and more sensate than dorsal skin. The options for rearrangement of volar tissue to cover the stump include:
In an acute setting, the "dog ears" should be left to decrease the tension and the likelihood of ischemia to the remaining flaps, and these dog ears disappear over time. Regarding the treatment of the bone in a digital amputation/stump formation, the bone under the stump end must be smooth. The remaining bone chips and devitalized bone should be removed. The articular cartilage can be preserved when the amputation occurs at the level of the interphalangeal (IP) joint. This can provide a shock pad for trauma and potentially causes less pain under than skin than the bone edges.
While addressing the nerve at the stump end, it is vital to avoid neuroma formation in this location. The nerve end should be in a position away from the stump end or an anticipated point-of-contact pressure. To decrease the likelihood of neuroma formation at the stump end, traction neurectomy of the digital nerve should be performed bilaterally for each digital amputation. Tendon insertions should be preserved where possible as the preservation of a tendon insertion enhances the active mobility and function of an amputation stump. Adhesions can result, and so early mobilization of the digit is recommended.
Digit amputations tend to be a straight forward presentation, but infectious processes can mimic amputation leading to loss of fingers/toes.
Previous studies have found these factors to have a substantial effect on functional outcome:
Survival rates following replantation have been reported between 80 to 90%, although these figures have come from specialist institutions. It is also worth noting that venous repair improves survival regardless of the level of amputation. This fact is important, as the venous repair is not always possible, and as a result, it could lead to venous congestion. One solution would be to make a small distal incision to allow venous drainage or the use of leeches.
Complications classify according to the time of onset
Some patients require further surgery to improve their function, such as tenolysis, bone grafting, tendon transfer, etc. On average, following upper limb amputations, patients return to work within 2 to 3 months after injury. Studies show that functional recovery is better in more distal injuries than proximal, both in terms of movement and power.
Surgical replantation requires a multi-professional approach. In terms of surgery, specialist surgeon(s) would be required to perform the procedure efficiently and effectively. During the recovery period, skilled nursing care experienced in follow-up care of patients with amputations is vital to ensure good monitoring of the replant, and allow early detection of pending complications. Early involvement of occupational hand therapists is also vital (some say the most important part) to patient recovery and the return of normal function.
Evidence generally shows good outcomes in distal amputations, especially if venous repair is possible. However, the evidence is limited in patients who do not proceed to replant.
Even after the replantation, patients often require an extensive interprofessional rehabilitation effort of nurses, occupational therapists, and physical rehabilitation physicians to regain the function of the digit.
|||Win TS,Henderson J, Management of traumatic amputations of the upper limb. BMJ (Clinical research ed.). 2014 Feb 10 [PubMed PMID: 24516069]|
|||Reavey PL,Stranix JT,Muresan H,Soares M,Thanik V, Disappearing Digits: Analysis of National Trends in Amputation and Replantation in the United States. Plastic and reconstructive surgery. 2018 Jun [PubMed PMID: 29794703]|
|||Wolfe VM,Wang AA, Replantation of the upper extremity: current concepts. The Journal of the American Academy of Orthopaedic Surgeons. 2015 Jun [PubMed PMID: 26001429]|
|||Maricevich M,Carlsen B,Mardini S,Moran S, Upper extremity and digital replantation. Hand (New York, N.Y.). 2011 Dec [PubMed PMID: 23204960]|
|||Sebastin SJ,Chung KC, A systematic review of the outcomes of replantation of distal digital amputation. Plastic and reconstructive surgery. 2011 Sep [PubMed PMID: 21572379]|
|||Sagiv P,Shabat S,Mann M,Ashur H,Nyska M, Rehabilitation process and functional results of patients with amputated fingers. Plastic and reconstructive surgery. 2002 Aug [PubMed PMID: 12142667]|