Overview of Prosthetics

Prosthetists

Prosthetists

provide care to patients with partial or total absence of limbs by designing, fabricating, and fitting prosthesis or artificial limbs.

• Creating the design to fit the individual’s particular functional and cosmetic needs

• Selects the appropriate materials and components

• Makes all necessary casts, measurements, and modifications, evaluates the fit and function of the prosthesis on the patient

• Teaches the patient how to care for the prosthesis

roles of the prosthetist.

Prosthesis

- is used to provide an individual who has an amputated limb with the opportunity to perform functional tasks, particularly ambulation, which may not be possible without the limb

- may also be made for use during activities or sports

- determined largely by the extent of an amputation or loss and location of the missing extremity

Amputation

- absence of all or part of a limb as result of surgery, trauma, or disease

- congenital or acquired

• Trauma

• Vascular Disease

• Infection

• Tumors

• Thermal, Chemical, or Electrical Injury

etiology of amputation.

• Trauma

• Disease and Tumors

etiology of amputation for UE.

• PVD

• Trauma

• Tumors

etiology of amputation for LE.

Amelia

absence of a limb.

Meromelia

partial absence of a limb.

Phocomelia

flipper like appendage attached to the trunk.

Adactayly

absent metacarpal or metatarsal.

Hemimelia

absence of half a limb.

Acheiria

missing hand or foot.

Aphalangia

absent finger or toe.

• Open Amputation (Guillotine Amputation)

• Closed Amputation

• Minor and Major Amputation

types of amputation

Open Amputations

- first of at least 2 operations required to construct a satisfactory stump

- must followed by secondary closure, reamputation, revision or plastic repair

• Infections

• Severe traumatic wounds with extensive destruction of tissue and gross contamination by FB te

indications of open amputation.

• Inverted skin flap

• Circular open amputations with post operative skin traction

• Vacuum assisted closure

techniques in open amputation

• Amputation level

• Contour of the residual limb

• Expected function of the prosthesis

• Cognitive function of the patient

• Vocation of the patient

• A vocational interest of the patient

• Cosmetic importance of the prosthesis

• Financial resources of the patient

considerations when choosing a prosthesis.

• Poor fitting of the prostheses

• Walking with prosthesis on takes extra energy

• The stump should be checked every day for redness, blisters, soreness, or swelling

• Prosthesis need to be adjusted several times before it fits well

problems may occur when using prosthesis.

Interscapulothoracic Amputation

- used less frequently

- only made necessary as part of the surgical intervention to remove a malignant lesion or the result of severe trauma

- most difficult to fit with a functional prosthesis due to:

• number of joints to be replaced

• multiple DOF available for control

• problems related to maintaining secure suspension of the prosthesis

Shoulder Disarticulation

- in this amputation, the rotator cuff tendons should be sutured together over the glenoid wing; the deltoid is attached to the inferior glenoid and lateral scapular border to fill the subacromial space

- it involves unique and challenging prosthetic problems - incorporates the greatest number of prosthetic components

- prosthetics components are similar to those for the transhumeral prosthesis with the addition of a shoulder unit, which allows passive positioning of the shoulder joint in flexion-extension and abduction-adduction

• Complete enclosure shoulder socket

• X-frame shoulder socket

commonly used designs for shoulder disarticulation.

Transhumeral Amputation

- most common satisfactory amputation in the upper extremity

- above elbow

- the more humeral length is preserved, the more optimal the prosthetic restoration

• very short

• short

• standard

• long

Short

transhumeral amputation that preserves 30% to 50% of length, which results in loss of GH motion because of the inhibition of the prosthetic socket that encompasses the acromion.

Long

transhumeral amputation that preserves 50% to 90% of length relative to the sound side, GH motions are preserved and uninhibited by the prosthetic socket.

Internal Elbow Joint

- the standard elbow component for the transhumeral prosthesis

- allow for 135 degrees of flexion and can be manually locked into a number of preset flexed positions

- incorporated a turntable that allows passive internal or external rotation of the forearm

Elbow Disarticulation

- a variant of the transhumeral prosthesis; the socket is flat and broad distally to conform to the anatomic configuration of the epicondyles of the distal humerus

- provides some self suspension and allows the individual with an amputation active rotation of the prosthesis

- advantages:

• reduction in surgery time and blood loss

• provides improved prosthetic self suspension

• reduces the rotation of the socket on the residual limb

- disadvantages:

• marginal cosmetic appearance caused by the required external elbow mechanism

• current limitations in technology which impede the use of externally powered elbow mechanism

Transradial Amputation

- preferred in most cases

- most common level because it allows the highest level of functional recovery

Short BE

defined as 0% to 35% preservation, which results in difficult prosthetic suspension and the additional loss of full ROM at the elbow.

Medium BE

- preserves 35% to 55% length, but pronation and supination with a prosthesis are lost

- elbow flexion is reduced because of the inhibiting prosthesis

Long BE

- preserves 55% to 90% length,

- allows up to 60% degrees of supination and pronation with a prosthesis, and maintains strong elbow flexion

Short Transradial Amputation

- can complicate suspension

- limit elbow flexion strength and elbow ROM

Medium Forearm Residual Limb

- preferred when optimal externally powered prosthetic restoration is the goal

- length typically permits good function and cosmesis

Long Forearm Residual Limb

- preferred when optimal body-powered prosthetic restoration is the goal

- ideal level for the patient who is expected to perform physically demanding work

Krukenberg Amputation

- converts transradial amputation to radial and ulnar pincers

- indicated for blind people

Wrist Disarticulation

- not commonly done:

• difficult socket fabrication.

• conventional wrist units are too long and cannot be used

• harder to fit with a myoelectric prosthesis

Hemicorporectomy

- amputation of the lower limbs and the pelvis (translumbar amputation)

- during this procedure the bony pelvis, pelvic contents, lower extremities, and external genitalia are removed following disarticulation of the lumbar spine and transection of the spinal cord

- a last resort for life-threatening conditions such as advanced pelvic tumors, pelvic osteomyelitis, crushing pelvic trauma, or intractable decubitis in the pelvic region

Hemipelvectomy

- resection of the lower half of the pelvis (hip disarticulation; transpelvic amputation)

- they vary greatly in the amount of bone removed, they range from focal osteotomy to a complete transaction of the pelvis that spares only the sacrum

- the prosthesis for this resembles that for the hip disarticulation except in the interior configuration of the socket

- most of the weight is borne by the soft tissues on the amputated side, with some of the weight being borne by the sacrum, the rib cage, and the opposite ischial tuberosity

Hip Disarticulation

amputation through the hip joint with pelvis intact.

Transfemoral Amputation

- Above knee amputation (AKA)

• short above knee

• middle above knee

• supracondylar amputation

- the primary surgical goal is to stabilize the femur while retaining maximal femur length

- there are two standard socket design (prosthesis) for this type of amputation:

• quadrilateral design

• ischial containment design

Knee Disarticulation

- amputation through the knee joint with whole femur still intact

- similar to the syme amputation, full weight bearing on the distal end of the KD residual limb is usually possible and the anatomic flare of the femoral condyles can be used for self-suspension of the prosthesis, because of the improved distal weight bearing, the KD amputation does not require an ischial weight-socket leading to enhanced comfort and sitting tolerance as does a transfemoral amputation

Gritti-Stokes Amputation

in which the femoral condyles are transecting just proximal to the joint and the patella is attached to the metaphyseal bone.

Below Knee Amputation

- transtibial amputation

- the most common amputaiton level seen in general practice

• Long BKA

• Medium BKA

• Short BKA

• Very Short BKA

Long BKA

- are sometimes performed to give patients a longer lever arm and more surface area for load distribution

- no functional muscle attachments are saved with this, and it is associated with multiple complications and poorer cosmesis

Syme Amputation

- transmalleolar amputation

- ankle disarticulation with attachment of the heel pad to the distal end of the tibia

- its goal is to have significant distal load bearing available, the amount of distal loading that is available is dependent on the individual

- advantage: there is a long residual limb and that it is an end weight bearing amputation

- disadvantage: the poor prosthetic cosmesis (because the distal residual limb is quite bulbous with a socket) and the limited prosthetic foot options

Boyd and Pirogroff Amputation

- are variations of the Syme’s where part of the calcaneus is fused to the distal tibia to lengthen the limb further and reduce limb length discrepancy

- these amputations also allow distal weight bearing, but the minimal limb shortening makes prosthetic fitting very challenging in adults

Boyd Amputation

amputation at the ankle with removal of the talus and fusion of the tibia and inferior calcaneus.

Pirogoff’s Amputation

amputation of the foot at the ankle, posterior part of the calcaneus being left in the stump.

Chopart Amputation

amputation at the level of the midtarsals.

Lisfranc’s Amputation

amputation of the foot between the metartasus and tarsus.

Transmetatarsal Amputation

- is a very successful amputation

- in this case, the forefoot is transversely amputated through the shaft of the metatarsals. The remaining portions are usually beveled inferiorly with a predominantly plantar skin flap