Myoelectric Upper Extremity Prosthesis
The myoelectric upper extremity prosthesis is an advanced prosthesis only for the experienced body powered upper extremity prosthesis user.  This is not the first type of prosthesis that the upper extremity amputee should be prescribed post upper extremity amputation. A minimum of a six month period of successful daily use and compliance with conventional upper extremity prosthesis is required before consideration of a myoelectric upper extremity prosthesis.

i-Limb Hand Prosthesis
The myoelectric hand prosthesis (i-Limb) is an advanced alternative to the hook terminal device for eligible patients with traumatic upper extremity amputation(s) or congenital upper extremity limb deficiency (ies).

Indications

Myoelectric upper arm prosthetic components and myoelectric hand prostheses may be considered medically necessary when the following conditions are met:

• The patient has an amputation or missing limb at the wrist or above (forearm, elbow etc); and
  
  
• Standard body-powered prosthetic devices cannot be used or are insufficient to meet the functional needs of the individual in performing activities of daily living; and
  
  
• Evaluation indicates that a myoelectric prosthesis meets the functional needs of the individual in performing activities of daily living and that the patient has demonstrated sufficient physiological and cognitive function to allow effective operation of a myoelectric prosthetic device; and
  
  
• The patient must be able to tolerate the weight of the upper extremity myoelectric prosthesis; and
  
  
• The patient retains sufficient microvolt threshold in the residual limb to allow proper function of the prosthesis; and
  
  
• The member does not function in an environment that would inhibit function of the prosthesis (i.e., a wet environment) or a situation involving electrical discharges that would affect the prosthesis; and
  
  
• The patient is free of comorbidities that could interfere with the function of the prosthesis (neuromuscular disease, etc.)
  
  

Because of expected normal growth and development, pediatric upper extremity amputees typically require upper extremity prosthesis replacement or refitting at 18 month intervals.

Amputees should be evaluated by an independent qualified professional (physiatrist or orthopedic surgeon with training and experience in providing rehabilitation of upper extremity amputees along with a prosthetist also with training and experience in fitting/fabrication of upper extremity myoelectric prosthetics) to determine the most appropriate prosthetic components and control mechanism. Consideration should be given to the amputee’s needs for control, durability (maintenance), function (speed, work capability), and usability.

Reimbursement may be made only if there is sufficient documentation in the patient’s medical record showing functional need for the myoelectric upper limb prosthesis. This information must be retained in the physician’s or prosthetist’s files, and be available upon request.

Limitations

Upper myoelectric prostheses and myoelectric hand prostheses would be contraindicated and not medically necessary in the following circumstances:

• Patients that routinely lift heavy items.
• Environmental exposure to dirt, dust, grease, water and solvents.
• Upper extremity residual limb neuromas or phantom pain exacerbated by upper extremity prosthesis use.

A participating, preferred, or network provider cannot bill the member for the denied service unless the provider has given advance written notice, informing the member that the service may be deemed not medically necessary and providing an estimate of the cost. The member must agree in writing to assume financial responsibility, in advance of receiving the service. The signed agreement should be maintained in the provider's records.

Description

Myoelectric Upper Extremity Prosthesis
Upper limb prostheses are used for amputations at any level from above the wrist to the shoulder. The primary goals of the upper limb prosthesis are to restore natural appearance and function. Achieving these goals also requires sufficient comfort and ease of use for continued acceptance by the wearer. The difficulty of achieving these diverse goals with an upper arm prosthesis increases as the level of amputation (hand, wrist, elbow, and shoulder), and thus the complexity of joint movement, increases.

Upper limb prostheses are classified into three categories depending on the means of generating movement at the joints: passive, body-powered, and electrically powered movement. All three types of prostheses have been in use for over 30 years; each possesses unique advantages and disadvantages.

• The passive prosthesis is the lightest of the three types and is described as the most comfortable. Since the passive prosthesis must be repositioned manually, typically by moving it with the opposite arm, it cannot restore function.
  
  
• The body-powered prosthesis utilizes a body harness and cable system to provide functional manipulation of the elbow and hand. Voluntary movement of the shoulder and/or residual limb extends the cable and transmits the force to the terminal device. Prosthetic hand attachments, which may be claw-like devices that allow good grip strength and visual control of objects or latex-gloved devices that provide a more natural appearance at the expense of control, can be opened and closed by the cable system. Patient complaints with body-powered prostheses include harness discomfort, particularly the wear temperature, wire failure, and the unattractive appearance. 
  
  
• Myoelectric prostheses use muscle activity from the remaining limb for the control of joint movement. Electromyographic (EMG) signals from the residual limb are detected by surface electrodes, amplified, and then processed by a controller to drive battery-powered motors that move the hand, wrist, or elbow. Although upper arm movement may be slow and limited to one joint at a time, myoelectric control of movement may be considered the most physiologically natural. Myoelectric hand attachments are similar in form to those offered with the body-powered prosthesis, but are battery powered. An example of recently available technology is the SensorHand™ by Advanced Arm Dynamics, which is described as having an AutoGrasp feature, an opening/closing speed of up to 300 mm/second, and advanced EMG signal processing. Patient dissatisfaction with myoelectric prostheses includes the increased cost, maintenance (particularly for the glove), and weight. 
  
  
• A hybrid system, a combination of body-powered and myoelectric components, may be used for high-level amputations (at or above the elbow). Hybrid systems allow control of two joints at once (i.e., one body-powered and one myoelectric) and are generally lighter and less expensive than a prosthesis composed entirely of myoelectric components.

Technology in this area is rapidly changing, driven by advances in biomedical engineering and by the U.S. Department of Defense Advanced Research Projects Agency (DARPA), which is funding a public and private collaborative effort on prosthetic research and development. Areas of development include the use of skin-like silicone elastomer gloves, “artificial muscles,” and sensory feedback. Smaller motors, microcontrollers, implantable myoelectric sensors, and re-innervation of remaining muscle fibers are being developed to allow fine movement control. Lighter batteries and newer materials are being incorporated into myoelectric prostheses to improve comfort.

Manufacturers must register prostheses with the restorative devices branch of the U.S. Food and Drug Administration (FDA) and keep a record of any complaints, but do not have to undergo a full FDA review.

i-Limb Hand Prosthesis
The i-Limb Hand imitates the true movement and accuracy of the human hand.  The i-Limb has five independently powered digits which give the fingers a lifelike action.  The fingers have the ability to bend at each joint and open and close around objects.  The i-Limb Hand is anatomically correct both when resting and in motion.

The myoelectric technology utilizes electrical signals in the muscles of a patient’s remaining limb which in turn controls the movement of the hand.  Two small metal electrode plates are placed against the skin, one on the top of the forearm and the other on the bottom.  These electrodes detect the minute electrical signals generated by the remaining muscles in the residual limb.

Traditional myoelectric devices offer only one grip pattern which must generate a stronger-than-human grip force at the tip, where the fingers meet, in order to successfully hold heavy or odd-shaped items.

The i-Limb Hand, with its individually motorized fingers, has the ability to articulate, or wrap around objects, and rotate the thumb, enabling the hand to create many different grips.  This allows a patient to grasp objects as a real hand would and perform more complex daily tasks such as typing, dialing the phone, throwing a baseball or shaking hands.

Coverage for prosthetics is determined according to individual or group customer benefits.

This medical policy may not apply to FEP.  Medical policy is not an authorization, certification, explanation of benefits, or a contract.  Benefits are determined by the Federal Employee Program.

Egermann M, Kasten P, Thomsen M.  Myoelectric hand prostheses in very young children.  Int Orthop. 2008 Jul 18.

Bouwsema H, van der Sluis CK, Bongers RM.  The role of order of practice in learning to handle upper-limb prosthesis.  Arch Phys Med Rehabil.  2008 Sep;89(9):1759-64.

Pylatiuk C, Schulz S, Doderlein L.  Results of an internet survey of myoelectric prosthetic hand users.  Prosthet Orthot Int.  2007 Dec;31(4):362-70.

Biddiss E, Chau T.  Upper-limb prosthetics:  critical factors in device abandonment.  Am J phys Med Rehabil. 2007 Dec;86(12):977-87.

Biddiss EA, Chau TT.  Upper limb prosthesis use and abandonment:  a survey of the last 25 years.  Prosthet Orthot Int.  2007 Sep;31(3):236-57.

Carey SL, Highsmith Jason M, Maitland Me, Dubey RV.  Compensatory movements of transradial prosthesis users during common tasks.  Clin Biomech (Bristol, Avon).  2008 Nov;23(9):1128-35.

Uellendahl Jack E., CPO.  Upper extremity myoelectric prosthetics.  Physical medicine and rehabilitation clinics of North America.  Volume 11: Number 3: August 2000.

Blue Cross Blue Shield Association.  Myoelectric prosthesis for the upper limb.  Medical Policy Reference Manual 1.04.04.