Overview of Prosthetics

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

roles of the prosthetist.

- 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

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

- congenital or acquired

etiology of amputation.

etiology of amputation for UE.

etiology of amputation for LE.

absence of a limb.

partial absence of a limb.

flipper like appendage attached to the trunk.

absent metacarpal or metatarsal.

absence of half a limb.

missing hand or foot.

absent finger or toe.

types of amputation

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

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

indications of open amputation.

techniques in open amputation

considerations when choosing a prosthesis.

problems may occur when using prosthesis.

- 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

- 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

commonly used designs for shoulder disarticulation.

- 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

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.

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

- 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

- 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

- preferred in most cases

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

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

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

- elbow flexion is reduced because of the inhibiting prosthesis

- preserves 55% to 90% length,

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

- can complicate suspension

- limit elbow flexion strength and elbow ROM

- preferred when optimal externally powered prosthetic restoration is the goal

- length typically permits good function and cosmesis

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

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

- converts transradial amputation to radial and ulnar pincers

- indicated for blind people

- not commonly done:

• difficult socket fabrication.

• conventional wrist units are too long and cannot be used

• harder to fit with a myoelectric prosthesis

- 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

- 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

amputation through the hip joint with pelvis intact.

- 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

- 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

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

- transtibial amputation

- the most common amputaiton level seen in general practice

• Long BKA

• Medium BKA

• Short BKA

• Very Short 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

- 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

- 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

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

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

amputation at the level of the midtarsals.

amputation of the foot between the metartasus and tarsus.

- 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