Updated: 4/7/2020

Rehab & Prosthetics

0%
Topic
Review Topic
0
0
0%
0%
Questions
15 15
0
0
0%
0%
Evidence
21 21
0
0
0%
0%
Videos
4 4
https://upload.orthobullets.com/topic/9072/images/gait_patterns.jpg
https://upload.orthobullets.com/topic/9072/images/2_and_3_point.jpg
https://upload.orthobullets.com/topic/9072/images/bodypowered.jpg
https://upload.orthobullets.com/topic/9072/images/myoelectric.jpg
https://upload.orthobullets.com/topic/9072/images/myoelectric2.jpg
https://upload.orthobullets.com/topic/9072/images/bodypowered2.jpg
Introduction
  • The goal of prosthetics are to restore limb function to as close to original function
  • Requires a multidisciplinary team approach for coorindation of efforts to achieve the best outcome
  • Prosthetics
    • upper limb
      • limb salvage is ideal in the upper arm given lack of sensation with prosthetic
      • residual limb length is important for suspending prosthetic socket
    • lower limb
      • goals for prosthetic are comfort, easy to get on and off, light, durable, cosmetic, and functional
Gait
  • Antalgic gait describes any gait abnormality resulting from pain
    • shortened stance phase on the affected limb
  • Gait pattern of ambulation with an assistive device  
    • 3-point  
      • both the crutch and the injured limb move forward together with weight-bearing on the crutches followed by all of the weight on the uninjured limb 
    • 4-point
    • swing-to
    • swing-through
  • Crutch walking
    • requires more energy than walking with a prosthesis
    • muscles that need strengthening in preparation for crutch walking
      • latissimus dorsi
      • triceps and biceps
      • quads
      • hip extensors
      • hip abductors
  • Wheelchair propulsion
    • 9% increase in energy expenditure compared to ambulation in normal subjects
  • Ambulation assistive devices
    • cane
      • shifts center of gravity towards affected side when cane is used on contralateral side
    • axillary crutch
      • 2 axillary crutches are required for proper gait if lower extremity is non weight-bearing or toe-touch weight-bearing  
Upper Extremity Prostheses  
  •  Timing of prosthetic fitting
    • as soon as possible, even before complete wound healing has completed
      • better outcomes if fitted within 30 days
  • Midlength transradial amputation 
    • Myoelectric prostheses 
      • best candidate is a patient with a midlength transradial amputation 
      • transmits electrical activity to surface electrodes on residual limb muscles
      • advantages
        • better cosmesis
        • allows more proximal coverage
      • disadvantages
        • heavier and more expensive prosthesis
        • requires more maintenance
    • Body-powered prostheses 
      • indications
        • best for heavy labor with less maintenance needed
      • techniques
        • activate terminal device with shoulder flexion and abduction
        • center the harness ring just off the midline of C7 towards the non-amputated side 
      • advantages
        • moderate cost and weight
        • most durable prosthesis
        • higher sensory feedback
      • disadvantages
        • poorer cosmesis
        • requires more gross upper limb movement for proper function
  • Elbow disarticulation or above elbow amputation
    • requires a prosthesis to recreate functional motion of two joints (elbow and wrist)
      • this creates heavy and less efficient as the only solution
      • best function with least weight is achieved by combining the various options of myoelectric, body-powered, and body-driven switch components
  • Proximal transhumeral and shoulder disarticulation amputation
    • an amputation this proximal has lost the ability to create a lever arm with mechanical advantage
    • best option is a universal shoulder joint that is positioned in space with the contralateral arm
    • this can be combined with lightweight hybrid prosthetic components
  • Components
    • Terminal device
      • passive terminal device
        • more cosmetic but less functional than active terminal devices
      • active terminal device
        • more functional, but less cosmetic than passive terminal devices
        • either hooks and prosthetic hands with cables or myoelectric devices
      • grips
        • precision grip (pincer-type)
        • tripod grip (palmar grip, 3-jaw chuck pinch)
        • lateral pinch (key pinch)
        • hook power grip 
        • spherical grip
      • prehension devices
        • handlike device
          • thumb, index, and long finger components
          • may be covered with a glove for better cosmesis
          • good choice for office worker
        • non-hand prehension device
          • hook or two-finger pincer with parallel surfaces
          • may attach task-specific tools with quick release mechanism
          • good for physical labor
        • myoelectric devices
          • can only be used in an environment clean from dirt, dust, water, grease, or solvents
      • mechanisms
        • voluntary opening
          • device is closed at rest and opens with contraction of proximal muscles
          • more common than voluntary closing
        • voluntary closing
          • device is open at rest and residual forearm flexors grip the desired object
          • heavier and less durable than voluntary opening
    • wrist units
      • quick disconnect wrist
        • allows easy swapping of devices with specialized function
      • locking wrist unit
        • prevents rotation during grasping and lifting
      • wrist flexion unit
        • used in bilateral upper extremity amputees
        • placed on longer residual limb to allow midline activities (shaving, buttoning)
    • elbow units
      • rigid elbow hinge
        • indications
          • short trans-radial amputation with inability to pronate or supinate with maintenance of elbow flexion
      • flexible elbow hinge
        • indications
          • wrist disarticulation or long transradial amputation with sufficient pronation, supination, and elbow flexion and extension
    • shoulder units
      • due to increased energy expenditure and weight of prosthesis many choose to use a purely cosmetic prosthesis
      • indications
        • forequarter or shoulder level amputation
Lower Limb Prosthesis
  • Foot prosthesis
    • Single axis foot
      • ankle hinge allows dorsiflexion and plantar flexion
      • disadvantages
        • poor durability and cosmesis
    • SACH (solid ankle cushioned heel) foot 
      • indications
        • general use in patients with low activity levels
        • use is being phased out
      • disadvantages
        • overloads the nonamputated foot
    • Dynamic response (energy-storing) foot 
      • indications
        • general use for most normal activities
        • patients who regularly ambulate over uneven surfaces likely benefit from multi-axial articulated prostheses 
      • articulating and non-articulating dynamic-response foot prostheses are available
        • articulating
          • allows inversion, eversion, and rotation of the foot
          • indications
            • patients walking on uneven surfaces
          • advantages
            • allows inversion, eversion, and foot rotation
            • absorbs loads and decreases shear forces
            • flexible keels
              • acts as a spring to decrease contralateral loading, allow dorsiflexion, and provide a spring-like push-off
              • posterior projection from keel gives a smooth transition from heel-strike
              • sagittal split allows for inversion and eversion
        • non-articulating
          • have short or long keels
            • shorter keels are not as responsive and are indicated for moderate-activity patients
            • longer keels are indicated for high-demand patients
          • different feet for running and lower-demand activities available
    • Shanks
      • provide structural support between components
      • endoskeleton (soft exterior) or exoskeleton model (hard exterior)
      • can provide a lever arm for propulsion following transmetatarsal amputation 
  • Knee prosethesis
  • Indications
    • transfemoral and knee disarticulation amputations
    • patient functional status is an important consideration 
  • Six types of prostheses for AKA or through knee
    • polycentric (four-bar linkage) knee 
      • indications
        • transfemoral amputation
        • knee disarticulations
        • bilateral amputations
      • techniques
        • variable knee center of rotation
        • controlled flexion
        • ability to walk at a moderately fast pace
        • supports increased weight compared to constant friction knee
    • stance-phase control (weight-activated) knee
      • indications
        • older patients with proximal amputations
        • patients walking on uneven terrain
      • techniques
        • acts like a constant-friction knee in swing phase
        • weightbearing through the prosthesis locks up through the high-friction housing
    • fluid-control (hydraulic and pneumatic) knee
      • indications
        • active patients willing to sacrifice a heavier prosthesis for more utility and variability
      • techniques
        • allows for variable cadence via a piston mechanism
        • prevents excess flexion
        • extends earlier in the gait cycle
    • constant friction (single axis) knee 
      • indications
        • general use
        • patients walking on uneven terrain
        • most common pediatric prosthesis
        • not recommended for older or weaker patients
      • technique
        • hinge that uses a screw or rubber pad to apply friction to the knee to decrease knee swing
        • only allows a single speed of walking
        • relies on alignment for stance phase stability
    • variable-friction (cadence control)
      • technique
        • multiple friction pads increase knee flexion resistance as the knee extends
        • variable walking speeds are allowed
        • not very durable
    • manual locking knee
      • technique
        • constant friction knee hinge with an extension lock
        • extension lock can be unlocked to allow knee to act like a constant-friction knee
  • Socket
    • the connection between the stump and the prosthesis
    • computer screening technology can decrease time to socket fabrication  
    • preparatory socket may need to be adjusted several times as edema resolves
    • patellar tendon-bearing prosthesis is most common for BKA
    • transfermoral or quadilateral sockets make it hard to keep the femur in adduction
      • transfemoral allow 10 degrees of adduction and 5 degrees of flexion
  • Suspension systems
    • attaches prosthesis to residual limb using belts, wedges, straps, and suction
    • suction suspension
      • standard suction
        • form-fitting rigid or semi-rigid socket which fits onto residual limb
      • silicon suction
        • silicon-based sock fits over the stump and is then inserted into the socket
        • silicon provides an airtight seal between prosthesis and amputated stump
  • Pylon
    • simple tube or shell that attaches the socket to the terminal device
    • newer styles allow axial rotation and absorb, store, and release energy
    • exoskeleton
      • soft foam contoured to match other limb with hard outer shell
    • endoskeleton
      • internal metal frame with cosmetic soft covering
  • Osseointegration 
    • direct attachment of a prosthesis to the skeleton
    • may improve biomechanical advantage of prosthesis and rehabiliation
  • Terminal device
    • Most commonly a foot, but may take other forms
Prosthetic Complications
  • General issues
    • choke syndrome
      • caused by obstructed venous outflow due to a socket that is too snug
      • acute phase
        • red, indurated skin with orange-peel appearance
      • chronic phase
        • hemosiderin deposits and venous stasis ulcers
    • skin problems
      • contact dermatitis
        • most commonly caused by liner, socks, and suspension mechanism
        • treatment
          • remove the offending item with symptomatic treatment
      • cysts and excess sweating
        • signs of excess shear forces and improperly fitted components
      • scar
        • massage and lubricate the scar for a well-healed incision
    • painful residual limb
      • possible causes include heterotopic ossification, bony prominences, poorly fitting prostheses, neuroma formation, and insufficient soft tissue coverage
  • Transtibial prostheses   
    • swing-phase pistoning
      • ineffective suspension system
    • stance-phase pistoning
      • poor socket fit
      • stump volume changes (stump sock may need to be changed)
    • foot alignment abnormalities
      • inset foot
        • varus strain, circumduction and pain
      • outset foot
        • valgus strain, broad-based gait and pain
      • anterior foot placement
        • stable increased knee extension with patellar pain
      • posterior foot placement
        • unstable increased knee flexion
        • drop-off or knee buckling can be improved by moving the foot more anterior 
      • dorsiflexed foot
        • increased patellar pressure
      • plantar-flexed foot
        • drop-off and increased patellar pressure
    • pain or redness related to pressure
    • prosthetic foot abnormalities
      • heel is too soft
        • leads to excessive knee extension
      • heel is too hard
        • leads to excessive knee flexion and lateral rotation of toes
 

Please rate topic.

Average 3.7 of 35 Ratings

Thank you for rating! Please vote below and help us build the most advanced adaptive learning platform in medicine

The complexity of this topic is appropriate for?
How important is this topic for board examinations?
How important is this topic for clinical practice?
Questions (15)

You have 100% on this question.
Just skip this one for now.

(OBQ11.174) A 34-year-old female undergoes open reduction and internal fixation (ORIF) for the left lower extremity injury shown in Figures A-C. Her postoperative weight bearing protocol includes touch down weight bearing to the left lower extremity. Which of the following ambulatory support devices is most appropriate for this patient? Review Topic | Tested Concept

QID: 3597
FIGURES:
1

Double axillary crutch

93%

(2484/2665)

2

Single forearm (Lofstrand) crutch

2%

(41/2665)

3

Single axillary crutch

3%

(88/2665)

4

Double cane

1%

(19/2665)

5

Single platform crutch

1%

(20/2665)

L 1 C

Select Answer to see Preferred Response

You have 100% on this question.
Just skip this one for now.

(OBQ11.177) A 32-year-old man has difficulty walking 5 months after having an amputation as shown in Figure A. Gait analysis reveals a shortened stance phase and irregular toe off on the operative extremity. Which of the following would most likely improve his ambulation? Review Topic | Tested Concept

QID: 3600
FIGURES:
1

Solid ankle ankle-foot orthosis

7%

(226/3246)

2

Hip-knee-ankle-foot orthoses

1%

(25/3246)

3

University of California Biomechanics Laboratory (UCBL) insert

4%

(124/3246)

4

Full-length steel shank shoe modification

10%

(309/3246)

5

Full-length steel shank and rocker sole shoe modification

78%

(2533/3246)

L 2 C

Select Answer to see Preferred Response

You have 100% on this question.
Just skip this one for now.

(OBQ11.41) The pattern of ambulation shown with the assistive device in Video A is most appropriately described as which of the following? Review Topic | Tested Concept

QID: 3464
FIGURES:
1

Swing-to gait

55%

(1368/2486)

2

Drag-to-gait

1%

(33/2486)

3

Swing-through gait

32%

(795/2486)

4

3-point gait

5%

(129/2486)

5

4-point gait

6%

(138/2486)

L 4 C

Select Answer to see Preferred Response

You have 100% on this question.
Just skip this one for now.

(OBQ10.245) A prosthetic polycentric knee with hydraulic swing control is chosen for a very active 63-year-old transfemoral amputee. All of the following appropriately describe the features of this prosthesis EXCEPT: Review Topic | Tested Concept

QID: 3344
1

Flexes in a controlled manner

4%

(104/2767)

2

Variable cadence

8%

(223/2767)

3

Ability to walk at a moderately fast pace

5%

(130/2767)

4

Knee center of rotation is fixed anterior to the line of weight bearing

69%

(1911/2767)

5

Weighs more than a constant friction knee that has a manual extension locking mechanism

13%

(369/2767)

L 2 C

Select Answer to see Preferred Response

You have 100% on this question.
Just skip this one for now.

(OBQ10.195) Patients with transradial amputations are considered the best candidates for a myoelectric prosthesis. Each of the following are advantages of a myoelectric device compared to a body controlled device EXCEPT: Review Topic | Tested Concept

QID: 3287
1

Provide more proximal function

20%

(587/2956)

2

Better cosmesis

11%

(323/2956)

3

More sensory feedback

55%

(1624/2956)

4

Can be used in any position including overhead activities

8%

(247/2956)

5

Require less gross limb movement

5%

(153/2956)

L 4 C

Select Answer to see Preferred Response

You have 100% on this question.
Just skip this one for now.

(OBQ10.128) All of the following are advantages of a body-controlled prosthesis compared to a myoelectric prosthesis for patients with upper extremity amputations EXCEPT: Review Topic | Tested Concept

QID: 3221
1

Better for heavy labor activities

8%

(239/3025)

2

Decreased amount of harnessing

68%

(2067/3025)

3

Decreased amount of therapy for training

10%

(303/3025)

4

Lighter weight

10%

(313/3025)

5

Less prosthetic maintenance

3%

(84/3025)

L 2 C

Select Answer to see Preferred Response

You have 100% on this question.
Just skip this one for now.

(OBQ09.267) In consideration of a prosthetic knee, each of the following are advantages of choosing a polycentric knee with fluid control over a constant friction knee EXCEPT: Review Topic | Tested Concept

QID: 3080
1

Allows variations in cadence

5%

(65/1269)

2

Flexes in a more controlled manner

10%

(124/1269)

3

Lighter in weight

63%

(802/1269)

4

Improved stance control allows less energy expenditure

10%

(129/1269)

5

Overall length of the limb is shortened during initiation of a step reducing the risk of stumbling

11%

(136/1269)

L 2 C

Select Answer to see Preferred Response

Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK

You have 100% on this question.
Just skip this one for now.

(OBQ08.266) A 45-year-old patient with a below knee amputation is interested in hiking as a hobby. He would like to know more about his SACH foot before selecting a different terminal device. A SACH foot or non-dynamic response (non-energy storing) foot, as compared to the dynamic response foot (energy storing) demonstrates all of the the following EXCEPT: Review Topic | Tested Concept

QID: 652
1

Less frequent replacement

13%

(148/1126)

2

Less dorsiflexion

9%

(98/1126)

3

Longer duration midstance of gait

40%

(453/1126)

4

Increased ground reaction forces to the contralateral limb

28%

(311/1126)

5

Diminished maximal gait velocity

9%

(105/1126)

L 4 C

Select Answer to see Preferred Response

You have 100% on this question.
Just skip this one for now.

(OBQ08.146) Which of the following amputations has the LEAST increase in metabolic demand for walking compared to a healthy patient without amputation? Review Topic | Tested Concept

QID: 532
1

Traumatic transtibial amputation

78%

(2158/2761)

2

Vascular transtibial amputation

18%

(497/2761)

3

Vascular thru-knee amputation

1%

(35/2761)

4

Traumatic transfemoral amputation

1%

(20/2761)

5

Vascular transfemoral amputation

1%

(35/2761)

L 2 C

Select Answer to see Preferred Response

You have 100% on this question.
Just skip this one for now.

(OBQ06.254) A 44-year-old male with transtibial amputation is interested in doing more hiking as a hobby, however he has had difficulty negotiating uneven terrain with a solid-ankle, cushioned-heel (SACH) prosthetic foot. Which of the following modifications to the new prosthesis is most appropriate? Review Topic | Tested Concept

QID: 265
1

Single axis foot

1%

(9/1292)

2

Shortened keel articulated dynamic-response foot

20%

(252/1292)

3

Lengthened keel articulated dynamic-response foot

13%

(166/1292)

4

Sagittal split keel articulated dynamic-response foot

61%

(791/1292)

5

Rigid keel nonarticulated dynamic-response foot

5%

(60/1292)

L 3 D

Select Answer to see Preferred Response

You have 100% on this question.
Just skip this one for now.

(OBQ06.101) A 35-year-old woman with a transtibial prosthesis is seen to have knee buckling (i.e "drop-off") during terminal stance. What prosthetic modification would correct this problem?





Review Topic | Tested Concept

QID: 287
1

Dorsiflex prosthetic foot

7%

(122/1853)

2

Move foot more posterior

24%

(439/1853)

3

Increase flexibility/softness of keel

2%

(44/1853)

4

Move toe break of prosthesis more posterior

5%

(99/1853)

5

Move foot more anterior

61%

(1128/1853)

L 3 D

Select Answer to see Preferred Response

You have 100% on this question.
Just skip this one for now.

(OBQ06.12) A 27-year-old patient comes in for a new prescription for his below knee amputation prosthesis because it is not fitting properly. All of the following are complaints and examination findings consistent with a prosthetic foot that is placed too far inset EXCEPT: Review Topic | Tested Concept

QID: 23
1

Varus strain

3%

(65/2137)

2

Socket pain located medial and proximal

19%

(414/2137)

3

Increased knee extension during stance

34%

(735/2137)

4

Socket pain located lateral and distal

34%

(735/2137)

5

Circumducted gait

8%

(170/2137)

L 4 D

Select Answer to see Preferred Response

You have 100% on this question.
Just skip this one for now.

(OBQ05.243) A prosthetic foot which incorporates a multi-axis articulated foot assembly is recommended for which of the following amputees? Review Topic | Tested Concept

QID: 1129
1

Low functioning diabetic who needs to transfer bed to chair

0%

(0/1142)

2

Long distance runner with below knee amputation

10%

(110/1142)

3

Elderly male with above knee amputation

1%

(9/1142)

4

Below knee amputee who needs to regularly walk on uneven ground

87%

(988/1142)

5

10-year-old male with above knee amputation from osteosarcoma

2%

(28/1142)

L 1 D

Select Answer to see Preferred Response

You have 100% on this question.
Just skip this one for now.

(OBQ04.209) What is the most important factor when choosing an optimal lower limb prosthesis for an adult patient? Review Topic | Tested Concept

QID: 1314
1

Prosthesis cost

0%

(5/1774)

2

Patient comorbidities

1%

(16/1774)

3

Patient functional status

94%

(1671/1774)

4

Patient gender

4%

(65/1774)

5

Patient age

1%

(13/1774)

L 1 C

Select Answer to see Preferred Response

Evidences (36)
VIDEOS (4)
Topic COMMENTS (14)
Private Note