Prosthetics Considerations

Appendix C: Prosthetics Considerations

Prosthetics continue to evolve in terms of functional capabilities, socket design, and increased opportunities for persons with an amputation to participate in recreational and occupational activities. However, the advances in prosthetic design have not achieved the level where a prosthetic limb serves as a true replacement of the limb that was lost. The following discussion highlights some of the limitations of current prosthetic technology in the context of the varied, occasionally high-demand essential job functions of a law enforcement officer (LEO).

• The police physician should not equate an amputee’s sports-specific performance with the ability to safely and effectively perform essential law enforcement job functions. Most obviously, adaptive sport performance requires modifications to the existing prosthesis or a sports-specific prosthesis (i.e., for running, swimming, skiing). For example, while it may be reasonable for the LEO with an amputation to complete a 1.5 mile run wearing a running prosthesis as part of the agency’s standard physical test to document cardiopulmonary endurance, this type of prosthesis is unlikely to be optimal for other non-running tasks.
• Suspension systems/liners require washing and adequate air-drying time between wears. Lower extremity prosthesis wear-time is usually around 10 hours per day before the residual limb needs time to recover. Obtaining an extra silicon liner/suspension system may allow for longer duty assignments, although residual limb health is a continued concern. The residual limb should be washed and air-dried daily, which may be difficult with extended duty assignments. Prolonged heat and cold can also affect performance of various prosthetic components.
• The risk of unanticipated prosthetic dislodgement is unknown; however, a redundant suspension system should be discussed. Residual limb size may fluctuate with changes in outside temperature, thus affecting fit and requiring a break in activity to add or remove liner layers.
• Myoelectric limbs are powered by rechargeable batteries with battery life time ranging up to several days for some knee units. Adequate time between duty assignments is required for charging of the myoelectric limb. In general, myoelectric prostheses have alarm systems to warn of low battery charge. The reserve time from warning to assuming a default state should be considered. In most knee prostheses, the battery exhaustion default state is a locked extension stance position while others revert to a passive hydraulic status. Either of these defaults would change the prosthesis characteristics in terms of any prior evaluation of the wearer being able to safely and effectively perform law enforcement job functions and may then be considered incapacitation. Upper extremity myoelectric prosthesis battery life is generally less than in leg components. Prostheses may also use mechanical or battery-powered vacuum suspension systems. Loss of vacuum may lead to improper fit of the prosthesis and in turn, decreased performance.
• The latest prosthetic technology is not covered by traditional civilian health insurance due to the prohibitive costs of the newest components. Latest technology is often only available to persons injured in active duty military service or select workers’ compensation cases. At this time, prosthetic technology requiring implantable interfaces and/or targeted reinnervation is available only in specialized research settings.

It is also important that the police physician recognize that most prosthetics are classified by the Food and Drug Administration (FDA) as exempt Class I medical devices and thus are excluded from most FDA safety and effectiveness requirements.14 This classification allows the manufacture to be exempt from the collection of clinical data, thus making it difficult to find peer-reviewed scientific studies that prove the superiority of one prosthetic design or prosthetic component. Prostheses are also custom designed for each individual user. Therefore, it is unlikely that any specific recommendations can be given regarding the design and components of an ideal LEO prosthesis.

Different models from different manufacturers often have dissimilar functional profiles in terms of strengths and weaknesses. Thus, it is important that a certified, knowledgeable prosthetist be involved in the evaluation of prosthesis users for law enforcement positions. It is equally important that the police physician communicate clearly with the prosthetist regarding the law enforcement job functions in a manner that will help the prosthetist either evaluate the capabilities of a current prosthesis or advise an alternative. A listing of some job functions that may be affected by prosthetic use is provided in the forms for physician and prosthetist evaluation in Appendices D and E.