Academy Society Spotlight: Considering Amputation to Gain Function

By Jeremy Farley, CPO/L
Academy Spotlight text and graphic

While the percentage of upper-limb amputations is small compared to lower-limb amputations, injuries to the upper limb account for almost one-fifth of emergency room visits.1 Injury to the upper limb also has a higher impact on the individual's overall function. For example, according to American Medical Association guidelines, loss of a lower limb at the hip disarticulation level accounts for about a 40 percent impairment while loss of all fingers and the thumb is equivalent to a 54 percent whole-person impairment.2 While our lower limbs get us to where we want to go, our upper limbs are what allow us to interact with our environment. Our hands are used to communicate as well as to perform work and recreational activities, and they are an important part of how we define ourselves.

Currently, prosthetic technology is more adept at reproducing the abilities of the lower limb (i.e., walking, running, ascending and descending stairs, etc.) than replicating the functions of the upper limb. This shortcoming in prosthetic technology is one of the reasons surgeons attempt to salvage as much of the hand and upper limb as possible: It is considered better to have some function and sensation without pain than to have a prosthesis.3 The surgical techniques available to take a mangled limb and return it to some functional state are wide-ranging. After the injury, the medical team has to quickly decide the best course of action to return the injured individual to the best functional state possible. While there are some guidelines when deciding between amputation and limb salvage and/or replantation there is still ambiguity in the decision-making process.4 As dexterity, multiple degrees of freedom, and sensation are lacking or not well duplicated by prosthetic technology, it is considered better for the patient to have a functional "bad hand" than a "good amputation."5

Typically, multiple surgeries are performed on an injured upper limb. The benefit of performing restructuring or replantation surgeries is that they afford the greatest chance of returning the limb to a functional state.6 (Also, amputation is an available option if the surgical outcomes are unsatisfactory; however, once an amputation is performed, restoring lost tissue is significantly more difficult.) Further, composite tissue transplantations, such as hand transplants, are being performed with increasing frequency and may provide an alternative to traditional hand salvage surgeries. While hand transplantation allows comprehensive hand function to be restored to the patient, it comes with disadvantages.7 With the transplant, there is a need for the patient to undergo long-lasting and extensive rehabilitation along with lifelong immunosuppression. The drug therapy regime associated with immunosuppression carries a wide variety of negative side effects. Thus, the transplant may improve the patient's quality of life while possibly shortening his or her life expectancy. At some point, when working with a nonfunctional upper limb, it must be decided whether additional salvage surgery is necessary, or if an amputation, combined with prosthetic technology, may restore more function to the patient.

The literature indicates that a patient can achieve greater functional outcomes with replantation/ limb salvage compared to amputation.6 However, despite the best efforts of the surgical and rehabilitation team, the final outcome might not be as functional as was hoped. There are a variety of reasons for this, such as poor vascularization of the limb, joint fusing, scarring, adherent tissue, and infection. In these instances, the patient has options that may need to be considered in consultation with the physician and rehabilitation team. Each case is unique, and the benefits and consequences of each decision should be examined carefully.

If the limb is pain free, adequately functional, retains sensation, and provides some variation of basic grasp pattern, little prosthetic or orthotic intervention is typically necessary. Working with an occupational or physical therapist may be helpful for the individual to optimize function. This may take the form of learning alternate methods of performing tasks such as tying shoes, or using simple tools to make vocational or avocational tasks easier. If the patient lost fingers or a portion of his or her hand, a passive functional device may be used to restore cosmesis.

As the severity of the dysfunction increases, the amount of prosthetic or orthotic intervention typically increases. In the case of a flail limb, such as a brachial plexus injury, the intervention can range from simple to complex. On one end of the spectrum, a sling can be used to help unweight the shoulder and help protect the limb. Also available are hybridized "prosthosis" designs that utilize spring-loaded hinges at the elbow to help position the arm in space, along with adaptations for the use of prosthetic terminal devices.

At the opposite end of the spectrum from a shoulder sling lies externally powered options such as the Myomo MyoPro® myoelectric upper-limb orthosis.8 Each treatment has benefits and disadvantages and should be discussed. As it is unlikely to find one single contact who is an expert in all facets of treatment, personal and professional networks should be exploited when exploring options. Professional groups such as the American Academy of Orthotists and Prosthetists' Upper Limb Prosthetics Society can be used by clinicians to network and discover alternative treatments and other potential options.9 The Amputee Coalition can provide a point of contact for finding others who may have experienced a similar traumatic event, who may then be able to provide additional sources of information and inspiration.10

If, after multiple reconstruction surgeries, the limb remains nonfunctional, is painful, or does not reach functional potential, amputation may be an option. There are several factors regarding the process that must be discussed with the patient. Amputation is another procedure for the individual to endure in addition to the multiple surgeries already experienced. If the main desire for amputation is to relieve pain, it is important to note that there are scenarios in which the amputation may not remove the source of pain. Going through the surgical process itself can be a traumatic experience for the individual, and there will be additional downtime spent healing. The cost associated with the process is not just monetary-the patient must also consider the loss of personal time and work time, as well as the mental and emotional trauma of working through another surgery. After all the time the patient spent participating in rehabilitation for the injured limb, he or she must go through the process again with the prosthesis. An average of 20-30 hours of rehabilitation time is typically necessary as preparation for prosthetic use.11

There is, however, the real possibility of benefits to be gained after amputation. In the case of an overly sensitive or painful limb, the amputation may provide the patient with relief that previous surgeries had not. Typically, amputation will also offer more options for prosthetic care. In some cases, the attempt to provide a "bad" but functional hand can create a presentation that is challenging to fit with a prosthetic device. A revision surgery can create a residual limb that is not only more functional, but also more suitable for the application of prosthetic components.

Improvements in fitting techniques and materials have increased the comfort and usability of prostheses. Thus, surgical reconstruction can now be taken in consideration with current developments in prosthetic technology. For example, in recent years, advances in both body- and external-powered partial hand prostheses have allowed for a wider variety of presentations to be fit. Currently, external-powered digit systems require the amputation level to be proximal to the metacarpophalangeal (MCP) joint.12 This allows for the articulation point of the prosthetic digits to match more closely with the anatomic digits, providing a better functional grasp and improved cosmesis. Body-powered systems have been developed that allow for amputations that range from distal to the proximal interphalangeal joint to the MCP joint to be fit.13

Amputation at the transradial level can often provide a significant challenge in terms of balancing surgical and prosthetic considerations. From the surgical perspective, as the length of the transradial-level residual limb increases, pronation and supination of the forearm are preserved. A longer transradial-level residual limb also provides better distribution of the weight of the prosthesis, however, it prevents the patient from being fit with prosthetic components that provide more function, such as wrist rotators and wrist flexion units. Conversely, a slightly shorter transradial amputation can sacrifice a little of the pronation/supination and weight distribution while allowing room for devices such as wrist rotators and wrist flexion units. At the transhumeral level, a longer residual limb provides for easier prosthetic suspension but can provide challenges in matching the joint center of the prosthetic elbow with the anatomic elbow center. A slightly shorter transhumeral-level residual limb not only allows the patient to receive a more cosmetic solution, but it can allow the patient to be fit with a wider variety of body- and external-powered elbow components.

Prosthetic technology continues to develop and improve. Advances in control strategies, such as pattern recognition, make controlling the prosthesis easier than what was previously possible. Multiarticulating terminal devices continue to improve at replicating the grasp patterns of the human hand. Selection of the grasp patterns used to be limited to complex muscle movements, but methods now exist that allow the user to select the grasp pattern through simple gestures. Selecting control sites used to be limited to muscle sites that could be read through surface electrodes, but now implantable electrodes are being tested that allow a user to control both a hand and wrist in a simple and intuitive manner.

Injury to an upper limb and the recovery process is challenging for anyone to endure. Having to go through additional surgeries and rehabilitation for the potential of gaining more function can be a difficult decision for a patient to make. Like any other decision, there are pros and cons. Consultation with a physician and the rest of the rehabilitation team is a must to discover the potential options and consequences. While current upper-limb prosthetic technology is not as adept as anatomical limbs, advances continue to be made that narrow the gap and offer more options for replicating function.

Jeremy Farley, CPO/L, is a staff prosthetist at Touch Bionics, headquartered in Livingston, Scotland, and is a member of the Upper Limb Prosthetics Society of the American Academy of Orthotists and Prosthetists. He received a degree in biomedical engineering from Rensselaer Polytechnic Institute and a degree in P&O from the University of Texas at Dallas. His engineering background works in conjunction with his training in prosthetics to provide a comprehensive understanding of the intricacies of upper-limb prostheses.

Academy Society Spotlight is a presentation of clinical content by the Societies of the American Academy of Orthotists and Prosthetists in partnership with The O&P EDGE.

References

  1. Niska, R., F. Bhuiya, and J. Xu. 2010. National hospital ambulatory medical care survey: 2007 emergency department summary. National Health Statistics Reports 26: 1-31.
  2. Rondinelli, R. D., E. Genovese, and C. Brigham, eds. 2008. Guides to the Evaluation of Permanent Impairment, 6th edition. Chicago: American Medical Association.
  3. Dillingham, T. 1998. Rehabilitation of the upper limb amputee. In Textbook of Military Medicine: Rehabilitation of the Injured Combatant. Edited by T. Dillingham and P. Belandres, 33-77. Washington: Office of the Surgeon General, Department of the Army.
  4. Langer, V. 2014. Management of major limb injuries. The Scientific World Journal, Article ID 640430, 13 pages, 2014. doi:10.1155/2014/640430,
  5. Tintle, S. M., J. J. Keeling, S. B. Shawen, J. A. Forsberg, and B. K Potter. 2010. Traumatic and trauma-related amputations: Part I: General principles and lower-extremity amputations. Journal of Bone and Joint Surgery 92 (17): 2852-68.
  6. Graham, B., P. Adkins, T. M. Tsai, J. Firrell, and W. C. Breidenvach. 1998. Major replantation versus revision amputation and prosthetic fitting in the upper extremity: A late functional outcomes study. Journal of Hand Surgery 23 (5): 783-91.
  7. Salminger, S., A. D. Roche, A. Sturma, J. A. Mayer, and O. C. Aszmann. 2016. Hand transplantation versus hand prosthetics: Pros and cons. Current Surgery Reports 4: 1-7.
  8. Myomo, www.myomo.com/index.asp (accessed July 2016).
  9. American Academy of Orthotists and Prosthetist, www.oandp.org (accessed July 2016).
  10. Amputee Coalition, www.amputee-coalition.org (accessed July 2016).
  11. Fletchall, S. 2005. Returning upper-extremity amputees to work. The O&P Edge, 4 (8):28-33.
  12. Touch Bionics, www.touchbionics.com (accessed July 2016).
  13. Naked Prosthetics, www.npdevices.com (accessed July 2016).