Prosthetics & Phantom Limb Pain

Functional Impact of UE Amputations

• This presentation details the functional impact of upper extremity (UE) amputations.
• Different levels of UE amputations are discussed, including shoulder disarticulation, transhumeral, through elbow, transradial, partial hand, and digital (finger) amputations.
• The presentation also covers the different types of prostheses, distinguishing between myoelectric and body-powered prostheses.

Learning Objectives

• Understanding levels of upper extremity amputations and their functional consequences.
• Knowing different types of prostheses and their basic components.
• Differentiating between myoelectric and body-powered prostheses.
• Learning about basic upper extremity treatment protocols.

Levels of Amputations

• Shoulder disarticulation
• Transhumeral (above the elbow)
• Through elbow (at elbow joint)
• Transradial (below the elbow)
• Partial hand
• Digital (fingers)

Partial Hand and Digital Amputations

• Common causes of these amputations include trauma and congenital conditions.
• Common injuries often occur at work.
• These types of amputations frequently result in severe pain, hypersensitivity, and substantial functional limitations.

Digital and Partial Hand

• Functional limitations depend on which fingers and parts of the hand are affected.
• Impact is significant if the index or thumb are affected.
• Prosthetic options are often limited.
• Patients may need to trade function for cosmetic options.
• Desensitization is crucial after surgery.
• Desensitization techniques include tapping, vibration, submerging, rubbing, exercise, and gentle massage.

Edema Management

• Edema management is a vital component in the rehabilitation of patients with upper extremity amputations.
• Various methods for managing edema are presented, including the use of ice packs, compression bandages, and other types of therapeutic interventions.

Pen Device

• A pen device is a specialized assistive tool designed for individuals with upper extremity amputations.
• It is used to provide better control for writing and drawing.
• Different types of pen devices with various attachments are shown, each offering differing advantages for specific tasks.

Coffee Mug Grasping Device

• A device that assists with grasping coffee mugs is described.
• This type of assistive technology offers better gripping to enable an amputee to safely and easily grab coffee mugs and other similarly shaped containers.

Partial Hand Prosthesis

• Amputations may affect more than one finger or the palm.
• Functional prosthetics are available in higher quantities for partial hand amputations.
• The functional outcome of a prosthetic depends on the extremity level of amputation, if the thumb is involved, and the magnitude of any associated injuries.

Cosmetic Prosthesis

• Cosmetic prostheses aim to restore a natural aesthetic appearance for amputees.
• Images of prosthetic hands demonstrating varying degrees of detail and realism are shown.

Challenging Case

• Various images of challenging cases with upper limb amputations, representing diverse scenarios and individual needs, are showcased.

Wrist Hinged Prosthesis

• Suitable for transmetacarpal level only.
• Enables a cylindrical grip for support and holding items.
• Doesn’t facilitate wrist deviation or flexion; limited movement.

Transradial (Below Elbow)

• Ideal prosthetic length is half the forearm.
• Allows use of the residual limb for holding, and bi-manual tasks.
• Maintaining functional range of motion (AROM) at the elbow is crucial.
• Rehab emphasis on one-handed tasks.
• Significant functional impairment may occur if the dominant side is affected.
• Requires residual limb care for edema, wounds, and skin integrity.
• Shoulder strengthening is particularly important for successful prosthetic use.

Adapted Devices

• Various adaptable devices (e.g., jar openers, utensils) shown which are modified to assist in daily life functions and tasks.

Transradial Prosthesis

• Body-powered prostheses for this level are shown.
• This prosthesis type has limited degrees of freedom.

Parts of Below Elbow Prosthesis

• A diagram of the components of a below elbow prosthesis is included, highlighting components like the ball terminal, retainer, base plate, housing, cable, and hanger.

Parts of the Transradial Prosthesis

• A diagram illustrating the different parts of a transradial prosthesis is shown.

Terminal Devices

• Three main categories of prosthetic terminal devices (hooks, prehensors, and hands).

Terminal Devices - Hook

• Voluntary opening devices.
• A popular choice due to their simplicity and functional utility.
• Made from aluminum or stainless steel.
• Tines of the hook are sometimes coated, or textured for better grip.

Terminal Devices - Work Hook

• Includes features like a knife holder and wider opening tines.
• Various weights are available.
• Some work hooks incorporate wrist flexion.

Terminal Devices - Prehensor

• Voluntary closing device.
• Suitable for grasping small cylindrical objects.
• Offering a wider opening than a hook.
• Provides reduced surface area contact.
• Grip strength exceeds 100 lbs in some models.
• Typically made from aluminum, stainless steel, or titanium or some combination of the three. Often provides the option of a locking pin for holding an item.
• Available in different weights.

Terminal Devices - Hand

• The most cosmetically pleasing option.
• The hand terminal devices are designed for more naturalistic grasp.
• The most complex of the three device types, challenging in terms of gripping/opening.
• Typically substantial heavier than the prehensor or hook type.

UE Prosthetic Training

• Orientation of objects in the terminal device for picking and dropping.
• Body mechanics.
• Grading resistance.
• Positioning the terminal device for various tasks.
• Skin inspection.
• Donning and doffing prosthetic instructions.
• Planning and using environmental cues.

Body Mechanics

• Teach patients to:

  • Make tasks easier.
  • Choose appropriate device positions.
  • Limit trunk deviation.
  • Use for bi-manual tasks.
  • Use environmental objects for task completion.

• Adapt the surroundings in order to assist in completion of a task.

Grade the resistance

• Using elastic bands increase resistance to opening the terminal device for better training and developing skill with appropriate usage.

Positioning of the terminal device

• The prosthesis terminal devices can rotate, depending on the cable type.
• Flexion release buttons can support efficient tasks and limit the energy needed.

Skin Inspection

• Regular skin checks (at least every hour), in the early stages are essential to spot redness or pressure areas.
• Prosthetic liners/liners will address skin concerns.

Pain Management

• Medications like Gabapentin, Lyrica, and Morphine are used to alleviate pain.
• Positioning, desensitization, mirror therapy, visualization exercises, are therapies to aid in pain control.
• Ensuring appropriate fitting, managing edema, and relaxation techniques help address pain.

Mirror Therapy

• Used for phantom limb pain related to upper body amputations.
• Utilizes visual feedback to reduce phantom limb pain.
• It is essential amputees relax and focus.

Limitations of Body Powered

• Impact on the contralateral shoulder may occur.
• No active wrist movement is possible.
• Function varies in different arm positions.
• Large or heavy objects are difficult to manage.
• Limited grip strength.
• Devices typically do not resemble a natural hand form.
• Socket typically limits forearm rotation.

Degrees of Freedom (DOF)

• Joints in the hand and wrist have up to 21 degrees of freedom.

Movements of the Hand

• Hand and wrist movements synergize to create unique grip patterns matching task demands or tasks often involving 20-30 or more unique motions.

Myoelectric Prosthesis

• Utilizes electrical muscle activity for control.
• Cutaneous electrodes detect this activity, controlling a programmable, motorized device.
• Different terminal device types (hooks, grippers, hands) are possible variations on myoelectric prostheses.

Multifunctional Hands

• Modern myoelectric prosthetic hands are quite sophisticated and capable.
• These prostheses exhibit various configurations.
• Examples include the Bebionic, Michelangelo, ilimb, Vincent, and Taska models for prosthetic hands; often with adjustable or replaceable terminal components.

Bebionic v.3

• Manufactured by Otto Bock.
• Microprocessors controlling finger positions.
• Individual motors distribute weight to each finger.
• 14 programmable grip patterns.
• Soft finger pads.
• Holds up to 45kg load.

Future of Myoelectric Control

• Future developments focus on lighter weight, enhanced weight distribution, simultaneous control, articulating wrists, and more affordable options.

Outcome Measures

• Various assessment tools for measuring the effectiveness and outcomes of treatment protocols (e.g., Activities Measure for Upper Limb Amputees [AM-ULA], Disabilities of the Arm, Shoulder, and Hand [DASH], Assessment for Capacity for Myoelectric Control [ACMC], Orthotics Prosthetic User Survey [OPUS], Refined Clothespin Relocation Test for Clinical Assessment [RCRT], Short Form Health Survey [SF-36], Trinity Amputation and Prosthesis Experience Scales—Revised [TAPES-R]), Box and Blocks test, Southampton Hand Assessment Procedure (SHAP).

Summary

• Upper limb amputations limit function.
• Upper limb amputations have greater issues with hypersensitivity and phantom pain than lower limb amputations.
• Body-powered and myoelectric prosthetic options provide pros/cons and do not entirely replace a natural functional hand.
• Proximal amputations tend to have significant functional implications.
• Prosthetic hands can help return some level of function, but specialized tools are often needed to support certain tasks.

This quiz covers key concepts in prosthetics and phantom limb pain treatment. Topics include mirror therapy, limitations of body-powered prostheses, hand and wrist biomechanics, and considerations for digital and partial hand amputations. It also includes the goals of desensitization techniques.