Prosthetics: Choosing What is Right for You
Artificial limbs, also known as prostheses, are defined as devices that are used to replace a missing body part or member. They are a vital part of the rehabilitation process following an amputation and help restore mobility to patients, leading to better patient outcomes and less co-morbidities. Studies have shown that amputees who receive a prosthesis after amputation have fewer future incidents requiring hospitalization and lower overall healthcare expenditures.
Types of Prostheses
There are many different kinds of prostheses available to patients depending on their individual clinical needs. Prosthetics are generally categorized according to the part of the body that they are used to replace. Within these general classifications, there are many sub-classifications that describe specific features of the prosthesis that are used to control the device, whether it be body powered or controlled by microprocessors or other electronic means. As technology has advanced, prosthetic devices have gotten more powerful, more energy efficient, and closer to mimicking the function of the anatomical body parts they replace.
Choosing the right prosthesis
The style and type of prosthesis that is right for a patient is a decision that involves the patient, prosthetist, physician, and other healthcare professionals that are part of the rehabilitation team. Things that must be considered include the shape and status of the patient’s residual limb, the patient’s past medical history, any conditions that may affect the patient’s ability to use a prosthesis, and the patient’s functional abilities, commonly known as a “functional level”. Functional level assessment applies only to lower limb prostheses, specifically to components that replace the anatomical function of the hip, knee, ankle, and foot, and was originally developed for the Medicare program but has become widely accepted in the medical community as a means of measuring the patient’s ability or potential ability to use certain prosthetic devices in an effective manner. Functional level assessment is a measure of the patient’s ability or potential, not a specific device’s ability to function. When determining the patient’s functional level, things that must be considered include the patient’s age, vocation, activity level prior to amputation, current living circumstances, and any other criteria that are identified through evaluation by the physician, prosthetist, and other members of the rehabilitation team. Current functional levels range from K0 which describes amputees that do not have the ability or potential to ambulate while wearing a prosthesis to K4 which describes amputees who ambulate at the highest levels while wearing a prosthesis. Most insurance carriers coordinate coverage of certain prostheses to match the patient’s functional abilities, often reserving advanced technology devices for only those patients who meet the requirements of higher functional levels.
Partial Hand Prostheses
A partial hand prosthesis replaces the function of the anatomical hand and fingers when part of the hand has been amputated. Traditional partial hand prostheses use a simple open or closed position of the prosthetic terminal device to provide the ability to grasp items, replacing the basic function of the anatomical hand. Recent advances in technology have led to the development of partial hand prostheses that include independently controlled prosthetic fingers, further mimicking the anatomical hand.
A trans-radial prosthesis replaces the function of the anatomical hand, wrist, and forearm up to the elbow. Trans-radial prostheses use either a body powered system consisting of a shoulder harness, a series of control cables, and a terminal device; or a myo-electric system that relies on the amputee’s ability to contract certain muscles in the arm which activate electrodes that creates coordinated muscle, nerve, and brain function that directs the position and action of the prosthetic arm.
A trans-humeral prosthesis replaces the function of the anatomical hand, wrist, forearm, elbow, and upper arm up to the shoulder. Trans-humeral prostheses use the same control mechanisms as trans-radial prostheses but may use multiple systems to control movement of the elbow as well as the terminal device, whether it is a hook, hand, or other mechanism.