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 first one crutch is advanced, then the opposite leg, then the second crutch, then the second leg, and so on swing-to that in which the crutches are advanced and the legs are swung to the same point swing-through that in which the crutches are advanced and then the legs are swung past them 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 transfemoral or quadrilateral 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 (medialized) varus strain, circumduction and pain outset foot (lateralized) 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
QUESTIONS 1 of 14 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Previous Next (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? QID: 3597 FIGURES: A B C Type & Select Correct Answer 1 Double axillary crutch 93% (3360/3605) 2 Single forearm (Lofstrand) crutch 1% (54/3605) 3 Single axillary crutch 3% (117/3605) 4 Double cane 1% (27/3605) 5 Single platform crutch 1% (29/3605) L 1 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review Tested Concept Review Full Topic (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? QID: 3600 FIGURES: A Type & Select Correct Answer 1 Solid ankle ankle-foot orthosis 7% (286/4130) 2 Hip-knee-ankle-foot orthoses 1% (31/4130) 3 University of California Biomechanics Laboratory (UCBL) insert 4% (170/4130) 4 Full-length steel shank shoe modification 12% (503/4130) 5 Full-length steel shank and rocker sole shoe modification 75% (3104/4130) L 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review Tested Concept Review Full Topic (OBQ11.41) The pattern of ambulation shown with the assistive device in Video A is most appropriately described as which of the following? QID: 3464 FIGURES: V Type & Select Correct Answer 1 Swing-to gait 55% (1669/3045) 2 Drag-to-gait 2% (49/3045) 3 Swing-through gait 31% (954/3045) 4 3-point gait 6% (179/3045) 5 4-point gait 5% (167/3045) L 4 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review Tested Concept Review Full Topic (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: QID: 3344 Type & Select Correct Answer 1 Flexes in a controlled manner 4% (126/3322) 2 Variable cadence 9% (292/3322) 3 Ability to walk at a moderately fast pace 5% (158/3322) 4 Knee center of rotation is fixed anterior to the line of weight bearing 67% (2231/3322) 5 Weighs more than a constant friction knee that has a manual extension locking mechanism 14% (474/3322) L 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic (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: QID: 3287 Type & Select Correct Answer 1 Provide more proximal function 20% (663/3322) 2 Better cosmesis 11% (366/3322) 3 More sensory feedback 54% (1783/3322) 4 Can be used in any position including overhead activities 9% (303/3322) 5 Require less gross limb movement 6% (183/3322) L 4 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic (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: QID: 3221 Type & Select Correct Answer 1 Better for heavy labor activities 8% (272/3406) 2 Decreased amount of harnessing 67% (2272/3406) 3 Decreased amount of therapy for training 11% (359/3406) 4 Lighter weight 11% (376/3406) 5 Less prosthetic maintenance 3% (103/3406) L 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review Tested Concept Review Full Topic (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: QID: 3080 Type & Select Correct Answer 1 Allows variations in cadence 5% (81/1548) 2 Flexes in a more controlled manner 10% (162/1548) 3 Lighter in weight 61% (945/1548) 4 Improved stance control allows less energy expenditure 11% (175/1548) 5 Overall length of the limb is shortened during initiation of a step reducing the risk of stumbling 11% (169/1548) L 2 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic (OBQ08.146) Which of the following amputations has the LEAST increase in metabolic demand for walking compared to a healthy patient without amputation? QID: 532 Type & Select Correct Answer 1 Traumatic transtibial amputation 77% (2476/3202) 2 Vascular transtibial amputation 19% (600/3202) 3 Vascular thru-knee amputation 1% (44/3202) 4 Traumatic transfemoral amputation 1% (24/3202) 5 Vascular transfemoral amputation 1% (40/3202) L 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review Tested Concept Review Full Topic (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: QID: 652 Type & Select Correct Answer 1 Less frequent replacement 13% (177/1399) 2 Less dorsiflexion 9% (122/1399) 3 Longer duration midstance of gait 40% (561/1399) 4 Increased ground reaction forces to the contralateral limb 27% (377/1399) 5 Diminished maximal gait velocity 11% (148/1399) L 4 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic (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? QID: 265 Type & Select Correct Answer 1 Single axis foot 1% (15/1605) 2 Shortened keel nonarticulated dynamic-response foot 18% (291/1605) 3 Lengthened keel nonarticulated dynamic-response foot 12% (196/1605) 4 Shortened keel articulated dynamic-response foot 60% (961/1605) 5 Lengthened keel articulated dynamic-response foot 8% (126/1605) L 3 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic (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: QID: 23 Type & Select Correct Answer 1 Varus strain 3% (82/2558) 2 Socket pain located medial and proximal 19% (488/2558) 3 Increased knee extension during stance 34% (862/2558) 4 Socket pain located lateral and distal 35% (891/2558) 5 Circumducted gait 8% (211/2558) L 4 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic (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? QID: 287 Type & Select Correct Answer 1 Dorsiflex prosthetic foot 8% (177/2202) 2 Move foot more posterior 23% (514/2202) 3 Increase flexibility/softness of keel 3% (62/2202) 4 Move toe break of prosthesis more posterior 6% (140/2202) 5 Move foot more anterior 58% (1283/2202) L 3 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review Tested Concept Review Full Topic (OBQ05.243) A prosthetic foot which incorporates a multi-axis articulated foot assembly is recommended for which of the following amputees? QID: 1129 Type & Select Correct Answer 1 Low functioning diabetic who needs to transfer bed to chair 0% (3/1487) 2 Long distance runner with below knee amputation 10% (152/1487) 3 Elderly male with above knee amputation 1% (13/1487) 4 Below knee amputee who needs to regularly walk on uneven ground 85% (1260/1487) 5 10-year-old male with above knee amputation from osteosarcoma 3% (48/1487) L 1 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic (OBQ04.209) What is the most important factor when choosing an optimal lower limb prosthesis for an adult patient? QID: 1314 Type & Select Correct Answer 1 Prosthesis cost 0% (6/2189) 2 Patient comorbidities 1% (18/2189) 3 Patient functional status 95% (2079/2189) 4 Patient gender 3% (65/2189) 5 Patient age 1% (16/2189) L 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic
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