Let Them Walk! Current Prosthesis Options for Leg and Foot Amputees

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COLLECTIVE REVIEWS

et Them Walk! Current Prosthesisptions for Leg and Foot Amputees

aul CY Tang, MD, Karim Ravji, DPM, Jonathan J Key, DPM, David B Mahler, CPO, Peter A Blume, DPM,
auer Sumpio, MD, PhD, FACS
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mputation has been long used to alleviate both congenitalnd acquired ailments of the extremities. The Indian poemRig-Vieda” is the first written record of an amputationbetween 3500 and 1800 BC); it describes a warrior queenho lost her leg in battle and was fitted with an iron pros-

hesis.1 The majority of amputations in early history wereerformed for war injuries, legal punishment, and religiousacrifices.2

Early prostheses were rudimentary devices such as theeg leg or hooks.3 Advances in prosthetic design occurreduring the Renaissance period, the American Civil War,nd the two world wars, with an emphasis on recoveringimb function. The predecessor of the SACH (solid-ankle,ushioned heel) foot was initially devised by JE Hanger, aouthern soldier during the American Civil War. Interestnd awareness of the importance of prostheses duringorld War I prompted the organization of the American

rosthetics and Orthotics Association. The Artificial Limbrogram was developed with sponsorship from the Veter-ns Administration, the Department of Health, Education,nd Welfare, and the armed forces. Public support for theseesearch institutions led to the rapid development of mod-rn prosthetic technologies using innovative designs andaterials.The purpose of this article is to review current informa-

ion regarding indications and techniques of lower extrem-ty amputations, with an emphasis on current prostheticesigns to enable a functional limb.

ip disarticulationip disarticulation is a radical lower extremity amputation

nd has been performed with minimal alteration in tech-ique since it was first performed by Kirk in 1943. Boyd4

nd Slocum subsequently recommended a more anatomicissection designed to minimize blood loss and to aid pros-

ompeting Interests Declared: None.upported in part by the North American Center for Limb Preservation.

eceived August 24, 2007; Revised October 2, 2007; Accepted October 15,007.rom the Department of Surgery, Yale University School of Medicine, Newaven, CT.orrespondence address: Bauer Sumpio, MD, PhD, FACS, Department ofurgery, Yale University School of Medicine, 333 Cedar St, New Haven, CT

d6520.

5482008 by the American College of Surgeons

ublished by Elsevier Inc.

hetic use.5 Sugarbaker and Chretien6 emphasized optimaluture line placement, with muscular and soft tissue cover-ng the acetabulum, to improve prosthetic fitting and min-mize complications.

Mortality of the procedure corresponds to the diseasetiology and associated comorbidities. One study noted a4% combined mortality rate for hip disarticulation.7 If no

imb infection was present preoperatively, hip disarticula-ion for arteriosclerosis carried a 20% mortality rate. But ifreoperative limb infection was present, the mortality ratencreased greatly, to 60%.7 Preoperative limb infection inhe setting of trauma with associated ischemia resulted in a00% mortality rate.7 This group of patients also had a veryigh (60%) postoperative infection rate. To minimize wound

nfections, recent studies have recommended aggressiveound care and even transfemoral guillotine amputation be-

ore definitive hip disarticulation.7

Higher incidences of wound complications and mortal-ty for hip disarticulation have been found in operationserformed for ischemic indications, and have been attrib-ted to the occurrence of nonviable skin flaps.8,9 A high ratef wound infection was also found in individuals with ear-ier ipsilateral above-knee amputation (AKA). But this maye related to a delay in obtaining a definitive hip disartic-lation procedure. So, early operation for revascularizationr AKA for extremity ischemia, or both, have been recom-ended to minimize the need for hip disarticulation. If

evascularization in a compromised AKA cannot be per-ormed, initial hip disarticulation may be indicated.9

Hip disarticulation in patients with cardiovascular dis-ase has a 37% early postoperative mortality rate. This maye from the poor preoperative state of the patients or theime consuming and traumatizing nature of the opera-ion.10 There is a higher mortality rate in patients undergo-ng multiple operations when compared with primary op-rations.11 The complicated character of the surgicalroblems seen in these patients needing hip disarticulationan be illustrated by the fact that an average of 2.9 salvageperations and 2.3 major operations per patient are per-ormed on this population.10

rostheticshere are a number of prosthesis fitting protocols after hip
isarticulation. One common approach is to use a tempo-
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549Vol. 206, No. 3, March 2008 Tang et al Current Prosthesis Options for Leg and Foot Amputees

ary prosthesis in the first 6 months after discharge. Al-hough most patients who undergo hip disarticulations forumors are discharged with a prosthetic ambulatory status,nly 0% to 10% of vascular patients are able to achieverosthetic ambulation. These patients were mobile onlyith walkers or chairs; others are essentially bed bound.8

Because hip disarticulation amputees do not have aunctional hip, they rely on increasing and decreasing spineordosis for propulsion during prosthetic ambulation. Theeight of the prosthesis exerts an ambulatory load that

estricts movement and often results in easy fatigue.12 In-reased energy expenditure in hip prosthesis mobilizers arevidenced by an 82% increase in energy use and a 40%lower ambulation speed than in able-bodied individuals13

Table 1). Patients using the hip disarticulation prosthesisre able to achieve 61% of comfortable walking speed and0% of fast walking speeds of able-bodied persons.14,15

The Canadian hip disarticulation prosthesis (Fig. 1), in-roduced by McLaurimin in 1957, was the most com-only used prosthesis. This traditional design has beenodified through the years into modern prosthetic systems

uch as the Otto Bock Modular Endoskeletal hip prosthesisTable 2), which has developed into the prosthesis of choicen hip disarticulation. Advantages of the newer design in-lude the use of lighter weight materials such as titaniumnd carbon fiber composites, improved cosmesis, and flex-bility of use with interchangeable and adjustable compo-ents. The widely used socket consists of a basket-shapedocket enclosing almost the entire hemipelvis with a Sile-ian belt for suspension. Recently, a total suction socket andustom made pelvic belt has been introduced.14 The suc-ion hip prosthesis socket has been reported to enhanceroprioception and decrease piston-like action in the pros-hesis.14,15 It should be noted that the hip disarticulationrosthesis is aligned with the load axis passing anterior tohe knee joint during the stance phase. This helps the kneeoint to remain in extended position during load bearingnd stress.16

Patients using the Canadian hip disarticulation prosthe-is exert, on average, 2.3 times more energy than theirverage resting metabolic rate and have a comfortable am-

Abbreviations and Acronyms

AKA � Above-knee amputationBKA � Below-knee amputationICEROSS � Icelandic Roll-On Silicone SocketIPOP � Immediate postoperative prosthetic placementSACH � Solid ankle cushion heelTSB � Total surface bearing

ulation speed of 13 yards per minute. This is approxi- y

ately 1.7 times more energy expenditure than patientsith AKA.17 Other developments include the introductionf residual limb lengthening using the modular prosthesis.his involves implantation of a modular proximal femoral

eplacement prosthesis with a special rounded end piecend a large weight bearing surface (Mutars, Implantcastorp). The device is made of titanium-aluminum-vanadium

o minimize weight. The joint capsule is reconstructed from arivira tube. Refixation of the ileopsoas and gluteal muscless necessary for good functional outcomes.The prosthesis ishen covered with a well-perfused flap generally consistingf adductor muscles, rectus femoris, and biceps femorisuscles, which are supplied by the femoral vessels and

emoral and obturator nerves. Preliminary studies havehown good functional outcomes in patients ambulatingith and without crutches. Other strategies to preserve

esidual limb length with hip disarticulation include endo-rosthesis implantation into the distal residual limb andelective resection of the proximal femur and hip joint,ith preservation of the distal femur.18 Recent studies have

uggested that the intelligent knee prosthesis for can besed in conjunction with the hip disarticulation prosthesiso decrease energy expenditure in place of the constantriction knee joint with stance control.12

bove-knee amputationbove-knee amputation was the most commonly per-

ormed lower extremity amputation for vascular diseaseefore the 1960s. This procedure has the advantage ofchieving a healing rate that approaches 100%.The relativenergy cost of ambulation in AKA amputees is 63%, com-ared with 40% in able-bodied individuals, 43% in pa-ients with a Syme amputation, and 42% in patients withelow-knee amputation (BKA; Table 1). The maximumerobic capacity and walking velocity are higher for pa-ients with a BKA than for those with an AKA, with

able 1. Energy Expenditure and Ambulation Rate at Variousmputation Levels

mputation level

Energyexpenditure

above normal, % Ambulation rate, %

yme amputation 43elow-knee

amputationLong stump 10Short stump 40 80

nee disarticulation 71.5 31 (prosthesis fitting rate)bove-knee

amputation 63 38–50ip disarticulation 82 0–10 (vascular patients)

ounger individuals doing better than elderly patients.19

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550 Tang et al Current Prosthesis Options for Leg and Foot Amputees J Am Coll Surg

mong all amputees, only those with an AKA can ambu-ate faster using crutches compared with prosthesis alone.rutch-only ambulation in this patient population pro-uce respiratory quotients (0.97 versus 0.96) and heartates (130 versus 126 beats per minute) comparable tohose with prosthesis usage.19

Knee prosthesis design varies from the most rudimen-ary single axis knee to the state-of-the-art high tech “intel-igent” prostheses such as the “C-leg” (Table 2). The appro-riateness of each prosthetic option is determined byatient characteristics such as age, preamputation func-ional status, comorbidities, and rehabilitation goals. Care-ul consideration is necessary to ensure that reasonable pa-ient expectations are met. From the simple articulatednee, we have progressed to the fluid control knee prosthe-is, which allows swing control with either pneumatic orydraulic systems. Although knee disarticulation has beenecommended as a generally superior operation, accep-ance has been slow. This has been at least partly because ofhe difficulty of designing a prosthesis that would allowoth the native and prosthetic knees to be at the same level,nd issues with healing. Currently, novel technologies suchs the polycentric knee with an adjustable center of rotationave made knee disarticulation a much more attractiveption than it was previously. The “intelligent” prosthesisas allowed amputees with good ambulatory function toaximize their mobile potential by allowing activities at a

igher speed and achieving a more complex level of func-ion. In addition, software algorithms have been used toptimize gait dynamics and performance through data col-ected from sensors in the prosthesis.

asic knee prosthetic designshe most common type of knee is the single axis knee, inhich flexion and extension occur around a single axis.dvantages are its reliability, simplicity, low maintenance,nd low cost. This is a simple prosthetic knee that is rarelysed except in poorer developing countries. One of theost important design advancements for the prosthesis is

ontrol of the swing phase. The initial prototype was ariction based system in which an adjustable friction cellas pressed against the knee axle, resulting in a degree of

wing control. An elastic or spring loaded mechanism islso frequently provided to promote full leg extension be-ore heel strike (Table 2). Unfortunately, the friction swingontrol mechanism functions well in only one cadence ands difficult to use on irregular surfaces. Despite the simplic-ty of design and limitations, the single axis knee is a sur-risingly reliable and inexpensive design ideally suited tondividuals with restricted access to regular health care and

igure 1. (A) Otto Bock modular endoskeletal hip prosthesis,5,350-$7,350. (B) Single axis friction control knee prothesis,500-$740. (C) Fluid swing control locked knee mechanism, $650-980. (D) Fluid swing control open knee mechanism, $850-$1,300.E) “Intelligent” transfemoral microprocessor-controlled prosthesis,5,000-$7,300. (F) Four bar linkage polycentric knee joint, $25,500-36,700. (G) Hip disarticulation socket with hip joint.

rosthetic maintenance.20

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luid phase swing control mechanismsore advanced fluid swing-phase control mechanismsere developed to overcome some of the limitations posedy the friction-based swing-phase control. Fluid phase con-rol prostheses with either pneumatic or hydraulic mecha-isms are more able to function over a range of ambulationadences and speeds. Pneumatic units are based on com-ressible air, and are recommended for the slow or moder-te ambulator because vigorous walkers may “out-walk”his design. The advantage of this air-based mechanism,owever, is that it is much less sensitive to changes in am-ient temperature.20 The pneumatic swing control pro-ides nonlinear resistance for shin swing control. This re-ults from a progressive increase in air pressure withompression and transfer of air from one side of the pistono the other.21

Compared with the friction-control mechanism, a fluid-ontrol mechanism allows faster walkers to attain highermbulation speeds, and unequal excessive swing phasesre more pronounced with the constant friction mecha-ism. Overall, fluid-control mechanisms allow more op-imal ambulation performance than the constant frictionechanism.22

Hydraulic dampers are the most commonly used form ofluid swing control design. They function by restrictinglow of incompressible fluid (commonly silicone oil)hrough a fixed orifice. This results in a strong dampeningorce for shin swing motion. Basic designs respond to aarrow range of walking speeds with a laminar fluid flow.

able 2. Overview of Lower Extremity ProsthesesModel Advantages

tto Bock Modularndoskeletal hip prosthesis

Light weightImproved cosinesisFlexibility of use with interchang

componentsingle axis friction control

knee prosthesisInexpensiveVery reliable

luid swing control lockedknee mechanism

More stable knee mechanismLower energy expenditureLower heart rate

luid swing control openknee mechanism (HansMauch S-N-S cylinder)

Faster ambulationWide range of walking speeds

Intelligent” transfemoralmicroprocessor-controlledprosthesis (C-Leg)

Able to adjust swing speed accord“perceived” ambulation speed

Higher ambulation speeds

our bar linkage polycentricknee joint

Prosthetic knee bends on sittinglevel as contra lateral native kn

Stable center of rotationAnterior weight bearing axis

ore recent designs allow turbulent flow at higher ambu- d

ation speeds and exert a correspondingly higher force toampen shin swing. The patient can walk comfortably at auch wider range of walking speeds, from slow to racealking. As a rule, less active individuals will do well with

he basic and less expensive hydraulic units; vigorously ac-ive patients will benefit from the more advanced hydraulicnee design using turbulent flow.20

A number of additional features are incorporated intohe prosthetic knee to meet the needs of specific patientopulations. The locked knee mechanism (Table 2) is aeature more suited for weaker and less steady amputees.his includes the elderly amputee population, in whom the

ocked knee would actually enable higher walking speednd lower cardiac effort despite an awkward stiff-leggedait.20 Amputees with cardiac dysfunction also benefitrom the locked knee mechanism, resulting in a lower heartate and faster walking speed when compared with patientssing the open knee mechanism.23 Patients who are totallynable to control the knee, such as the stroke patient,ould also be suitable candidates for the locked kneeechanism.20 But younger and healthier amputees often

refer the open knee mechanism, which allows greater am-ulation speed. Despite greater energy costs and heart rate,he open knee mechanism functions well in those withreater physical and energy reserves.24

There are a number of commercially available hydraulicnee mechanisms using similar fluid control principles.he Hans Mauch S-N-S cylinder, (Table 2) is a widely usedydraulic knee mechanism. This is a high performance

Disadvantages Indications

High energy expenditureSlow ambulation

Able bodied patients posthip disarticulation

One cadenceDifficult to use on

irregular surfaces

Restricted access to regularhealth care

Lower ambulation speeds Weaker, less steadyamputees such as elderlyor stroke patients

Higher energyexpenditure

Higher heart rate

Patients in good physicalcondition with higherexercise demands

o ExpensivePatients with average

physique derive littleadditional benefit

Patients in excellentphysical conditiondesiring a high exercisecapacity

e Higher cost Ambulatory patients postknee disarticulation

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oordination, and reflexes to participate in challenging ac-ivities such as confident descent of inclines, walking downtairs, and performing step-overstep. The Otto Bock 3R80otary hydraulic knee prosthesis is a recent development inydraulic stance that incorporates a weight loading sensi-ive mechanism. The knee stance mechanism is engagedith normal weight bearing and automatically disengages

s weight is transferred to the leading limb during normalalking. This design is more suited for slow and limited

mbulation because the brake-stance mechanism may in-erfere with preswing knee flexion during the early phasesf walking.20

In general, individuals of smaller stature, such as womennd children who have a slow to moderate cadence, areore suited to the smaller, simpler, and lighter hydraulic

wing control units. Taller, more active ambulators, espe-ially those involved in competitive sports, will derive ben-fit from the larger, more powerful hydraulic swing controlechanisms.20

olycentric knee mechanismspolycentric knee mechanism consists of four points of

otation, each connected by a linkage bar (Table 2). Thisllows optimal control of swing and stance phases. Oneesign demonstrates minimal extrusion of the knee mech-nism during knee flexion to 90o. This permits better cos-esis during activities such as sitting, which is especially

mportant in patients with long femoral stumps. Anothereature of the polycentric knee is better stance stabilizationhile maximizing ease of preswing knee flexion. With a

enter of rotation being more proximal and posterior com-ared with the native knee, the device results in greater legxtension and prosthesis stability. When the knee flexesnly a few degrees, the center of rotation is shifted anteri-rly, with subsequent ease of continued flexion accompa-ied by a mild decrease in prosthesis length. This ensuresnee stability while the patient is walking at a moderate torisk pace. In addition, toe clearance can be increased by upo 1 to 2 cm during midswing, leading to less perceived riskf stumbling. This is preferred by patients who are in rela-ively good physical condition and desire stance phase kneetability.20

dvanced prosthetic knee technologiesn conventional pneumatic swing control devices, swingdjustment occurs in a nonlinear manner dependent on theize of the orifice through which air passes. “Intelligent”ransfemoral microprocessor-controlled prostheses canhange the orifice size according to varying walking speedso allow appropriate shin swing time. A knee joint sensoretects the swing speed and sends a signal to the stepperotor, which adjusts the valve size in the pneumatic

ylinder.21 a

An energy expenditure benefit has been shown at walk-ng speeds that are slower or faster than normal, with aecrease in oxygen consumption of 5% to 9% when com-ared with conventional pneumatic mechanisms. Ambu-

ating at speeds outside of those designed for conventionalydraulic mechanisms can lead to inefficient gait charac-eristics such as vaulting, circumduction, and excessive lat-ral sway.24

There are several available types of microprocessor-ontrolled prosthetic knees including the Endolite Intelli-ent Prosthesis Plus (Chas Blatchford & Sons), the Seattleimb Systems Power Knee (Seattle Limb Systems), and theecently released C-Leg (Otto Bock). The C-Leg (Table 2)s an advanced processor-controlled prosthesis that uses aydraulic cylinder to provide greater swing control andariable hydraulic stance phase control. The shin includesumerous sensors that accumulate biomechanical datauch as vertical loading amplitude and sagittal knee move-ent, and can also determine the direction and angular

cceleration of the knee joint. A software analysis systemptimizes prosthetic characteristics through a process ofata sampling and calculations of up to 60 times in a 1.2-econd gait cycle. Studies to date have demonstrated signif-cant benefit only in relatively healthy individuals who aretherwise good ambulators using conventional knee pros-hetic technology.20 When examined using the swing-phasereadmill test, the C-Leg has clearly demonstrated superi-rity at higher walking speeds when compared with me-hanical hydraulic knees such as the Otto Bock 3R45 andR80. The C-Leg has demonstrated greatest efficiency inhe areas of flexion angle, flexion speed, and extensionpeed. It was more beneficial at higher ambulation speed inhysically fit patients, with one report documenting aalking speed of up to 6.67 km per hour with the C-Leg.25

nee socket–residual limb interfacehere are generally two types of transfemoral sockets. Theuadrilateral socket allows direct ischial weight bearing,ith a relatively horizontal posterior brim exerting a verti-

al upward pressure on the ischium. On the other hand, theschial containment socket has a sloping contour in theosteromedial brim designed to rest the ischial tuberosity 3o 4 cm below the brim edge. This type of socket is usuallyecommended for patients engaged in high activity sportnd running. The ischial containment socket is usuallyecommended for short, fleshy, unstable stumps and is pre-erred by bilateral transfemoral amputees. A flexible brim isreferred for this particular socket. The quadrilateralocket is suited for longer firm residual stumps withntact adductor musculature. It is also useful in geriatricnd disabled persons who can use canes or walkers to
ssist in ambulation.26

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ehabilitation in above- andelow-knee amputationshe proportion of below-knee amputations increased in

he late 1960s and early 1970s because of a number ofdvancements. Incorporation of a posterior flap tech-ique performed with a better vascular supply led to an

mproved healing rate.27 Clinicians were also beginningo assess the appropriate amputation level based onoppler evaluation28 and measurement of transcutane-

us pO2.29 At the same time, revascularization tech-iques were being developed that resulted in salvage ofhreatened limbs or allowed a more distal level of ampu-ation. Increased awareness of the benefits of distal am-utation, relating decreased energy expenditure30,31 and

mproved rehabilitation potential,32 promoted the trendoward more distal amputations. Other significant de-elopments during this period include advances in theare of the diabetic amputee, and improved understand-ng of nutrition in stump healing.33

Recent major advances in the field of prosthetic technol-gy have had a major impact on surgical decision makingnd technique regarding lower extremity amputation level.here are major distinctions between AKA and BKA, in-

luding rates of healing and rehabilitation potential. Theres often a fine balance or compromise between increasedates of healing in AKA versus more optimal rehabilitationesults and better energy efficiency from BKA.

Of the patients who attained a healed stump, approxi-ately 80% of those with BKA were eventually able to

chieve ambulation.This is in contrast to only 38% to 50%f healed AKA patients achieving regular prosthetic ambu-ation.34,35 But these outcomes are counterbalanced by aower 65% to 89% healing rate with BKA as comparedith a greater than 90% healing rate with AKA.28 Not

urprising, an even lower prosthetic ambulation rate of9% is seen in bilateral lower extremity amputees.36 Theresence of coronary artery disease is also a strong negativeredictor of successful ambulatory rehabilitation. Of am-utees who are able to successfully achieve ambulation,8% of those with BKA have coronary artery disease asompared with 7% of AKA patients.37 This must be takennto consideration when determining the most suitablemputation level for a given patient.

nee disarticulationnee disarticulation has significant theoretic advantagesver conventional AKA including greater end-weight-earing along normal proprioceptive pathways, simplicityf technique, minimal blood loss, residual limb balancedy strong muscles, and less energy expenditure with aonger femoral stump. This technique is not often used
ecause of poor residual limb coverage by thin skin and a
ubcutaneous tissue, leading to a higher risk of tissue ische-ia and necrosis.37 It is interesting to note that the metaph-

seal cancellous bone and cartilage of the femoral condylesn knee disarticulation are more compliant than the diaph-seal cortical bone and have better shock absorption.38 Inatients with poor rehabilitation potential, a knee disartic-lation provides more optimal sitting balance, bed mobil-

ty, and transfer compared with an AKA.39

nergy expenditurehen compared with AKA amputees, through-knee am-

utees are able to achieve higher normal and maximumalking speeds ( 34.5 versus 24.5 m/min and 47.8 versus9 m/min, respectively), with lower relative (a ratio of en-rgy expenditure rate [mL O2 consumed/kg/min] at nor-al versus maximum walking speed) and functional energy

osts (a ratio of energy expenditure rate at normal walkingpeed versus at rest; 71.5 versus 87.7 and 0.092 versus.101, respectively). But more distal leg amputations haveetter ambulatory velocities and energy efficiency.30 Even ahort BKA is more advantageous than a knee disarticula-ion given that it is well tolerated by the patient and free ofomplications.40

Although many studies advocate limb length preserva-ion and knee joint preservation when possible in amputeesith peripheral vascular disease, it has been suggested that

n elderly patients, knee disarticulation may become a fa-ored option.37,38 Elderly amputees with peripheral vascu-ar disease do not seem to derive the theoretic benefit ofKA as compared with more healthy amputees. So it was

ound that knee disarticulation in patients who would oth-rwise heal a BKA allowed earlier weight bearing, with aower risk of the wound complications seen in BKA pa-ients. In addition, the ease of fitting, allowance for directoad transfer, and the stability of a polycentric knee mayutweigh the benefits of preserving a compromised nativeuadriceps-knee mechanism.39

rostheticshe socket design for a knee disarticulation prosthesislaces the biomechanical support at the femoral condyles, aeight bearing surface. The proximal trimlines of the

ocket do not need to contain the ischium with a highedial trimline, but can be lowered to approximately to

ne-third of the total limb length. Suspension can be ob-ained superior to the condyles through a variety of meth-ds that include pads, straps, cut out windows, and inflat-ble bladders made in the socket. Knee disarticulationrostheses have become much more cosmetically accept-ble for patients with the arrival of the four bar linkageolycentric knee joint (Fig. 1). With the older knee pros-hesis being simply applied to the end of the residual limb,
n inefficient gait pattern occurs, with the prosthetic knee

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otational axis being much too distal in comparison withhe contralateral native knee. The polycentric knee pro-ides an instantaneous stable center of rotation, an anterioreight bearing axis, and allows ease of prosthetic knee flex-

on on unloading. With the patient seated, the prostheticnee folds under the socket, allowing seating with bothnees on the floor.38

elow-knee amputationnergy expenditureatients with BKA have more efficient energy expenditureuring ambulation and can achieve higher ambulationpeeds when compared with patients with more proximalmputations.19,30 As perceived by the patient, the length ofhe BKA stump does not correlate with comfortable walk-ng speed. But objective measurements indicate that longtumps had only a 10% increase in energy expenditureompared with short stumps, which had a 40% increase innergy expenditure above normal.31

Interestingly, in able-bodied individuals,41 unilateralmputees,39 bilateral amputees,42 and patients with hip dis-rticulation,15 the chosen walking speed is commonly thatith the most energy efficiency or demand.

nee socket-stump interfacehe socket for a prosthetic limb is an important interfaceoverning parameters such as energy transfer to the pros-hesis and residual limb viability. There are a number ofactors to be considered before fitting a definitive prosthe-is. First, the residual limb should be “matured” by using aompressive stump shrinker. This process results in subcu-aneous tissue shrinkage, residual muscle atrophy and hy-ertrophy, and thigh and residual limb lengthening witheturn of collateral circulation.43

Although a BKA length can vary from 2 inches below thenee to just above the ankle, the usual recommendedength is approximately 6 inches, which allows for nearormal ambulation. In general, the ideal distal residual

imb circumference should be equal to or less than that athe level of the knee joint. An excessively bulbous residualimb may be difficult to fit.44 For residual limbs less than orqual to 4 inches, a patellar-tendon bearing prosthesisould be needed.43

The standard socket design for below-the-knee ampu-ees is the patellar-tendon bearing prosthesis, which waseveloped in the University of California at Berkeley in957. But not all patients tolerate this design, and someeport excessive pressure on the patellar tendon. Kneelexion may be limited, and adventitial bursae, skinbrasions, and dermatitis can develop.45 The total sur-ace bearing socket (TSB) uses suction for prosthetic
ecurement. Development of a silicone-lined socket al- a
ows improved pressure seal during high socket seal ac-ivities such as athletics, bending, and sitting. In a caseeries of 32 patients studied by Hachisuka and col-eagues,46 the TSB socket was well tolerated, with overallatisfaction reaching 75%. Patients were most satisfiedith the comfort, ease of swing, and less piston move-ent. It was believed that the weight was well distrib-

ted over the entire stump, with less pressure against theatellar tendon area. But donning the socket may beifficult in patients with visual, sensory, and motor def-

cits. The TSB socket is sensitive to changes in stumpircumference from edema or gradual decreases intump diameter with progressive stump maturity. Neg-tive issues associated with the TSB include distal stumpain, discomfort during knee flexion, and excessive per-piration inside the socket.46

Another socket that was developed in the mid 1980s washe Icelandic Roll-On Silicone Socket (ICEROSS). A pre-abricated roll-on sleeve, closed-end liner is turned insideut, then placed on the residual limb, and proximally rolledp over the knee. The socket is then secured onto the liner,ost commonly by means of a shuttle lock, in which a pin

n the end of the liner engages automatically with a springoaded clasping mechanism located in the bottom of therosthetic socket. The ICEROSS uses a silicone sleeve thats flexible and elastic, conforming very closely to the am-utee’s residual limb so that air is excluded and effectiveetention is maintained throughout gait despite minor vol-me changes. Friction is transferred to the outer portion ofhe liner and socket interface with the skin, with the innerortion of the liner remaining relatively friction free. So,he ICEROSS socket allows the stump to conform to aoncompliant socket. Care should be taken in prescribinghe ICEROSS socket to the elderly because of their com-romised ability to remain independent, and it should beone only if adequate handling and maintenance are as-ured. In addition, the ICEROSS socket should not beecommended if the patient is unable to don the prosthesisnd maintain proper hygiene.38

The below-knee bypass prosthesis (Fig. 2) is generallyndicated for delayed healing amputations and has the ad-antage of preventing the sheer forces applied by the con-entional total contact socket. It is also used in amputeesith residual limb pain, stump dermatolopathology, recent

kin grafting, or bone overgrowth. The advantage of thisrosthetic design is that the rehabilitation process can con-inue despite stump complications. This is particularly im-ortant for bilateral amputees, in whom prolonged bed restecondary to stump complications can lead to severe mus-le atrophy and can hamper or delay later rehabilitation
ttempts.47

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mmediate postoperative prosthetic placementhe idea of immediate postoperative prosthetic placement

IPOP) was first proposed by Berlemont in the late 1950s,nd the procedure was subsequently modified by Weiss andssociates.48 Rigid plaster IPOPs were used in the Unitedtates starting in the 1960s and required significant skill topply. It was not usually removed for up to 7 days.49 Earlyesults from IPOP were mixed, with one study in 1968howing a beneficial outcome in patients with BKA, with a0% primary healing rate and only 10% requiring a highermputation because of suboptimal healing. But other stud-es at the time noted a deleterious effect of IPOP, with a 10imes greater reamputation rate in BKA performed for pe-ipheral vascular disease, perhaps from further compromisef marginal vascular supply.50 Another report found noifference in wound healing, wound infection, stump ne-rosis, need for reamputation, and postoperative mortalityhen compared with soft dressing.51

In recent years, after lower extremity amputation, pa-ients are often fitted with a soft stump dressing that fol-ows the stump contour. The stump wound is allowed toeal, with daily dressing and wound assessment. The pa-ient remains nonambulatory until the fitting of a perma-ent prosthesis 4 to 6 weeks after surgery and may delayhysical therapy and rehabilitation.52 Recent studies sup-ort the use of IPOP to facilitate operative recovery, reha-ilitation, and achieve independent ambulation.53,54 Thereppears to be significantly less wound infection, fewer non-

Figure 2. Below-knee bypass prosthesis.

ealing wounds, and less surgical wound dehiscence re- a

uiring surgical debridement or reamputation at a higherevel. Overall, patients using IPOP experienced feweround complications, with improved wound healing and

arlier prosthetic fitting and training.Conventional IPOPs use inflatable air cells placed inside

universally sized rigid shell that can be inflated to fit theimb stump (Air-limb [Aircast]) and is secured with straps.he Air-limb is inflated to 20 to 30 mmHg, and a knee

uspension sleeve is applied.54

rosthetic foothe prosthetic foot serves as an important, multifaceted

omponent of all lower extremity prostheses. The primaryurpose of the prosthetic foot is to serve as the anatomicnkle and foot. A prosthetic foot should provide the func-ions of joint simulation, shock absorption, a stable weightearing base of support, muscle simulation, and cosmesis.here are essentially four different designs of prosthetic feet

Fig. 3). The SACH (solid ankle cushion heel) foot is theost frequently used foot (Fig. 3A). It consists of a rigid

eel covered by a semi noncompressible foam, and a syn-hetic rubber heel wedge. The cushion heel compresseshen weight is applied, allowing the forefoot to approach

he floor. The amount of this simulated plantar flexionepends on the relative softness of the heel material andeight of the amputee. Because the keel is rigid, the SACH

oot does not provide dorsiflexion. SACH feet are relativelynexpensive and are manufactured in a wide range of sizes.

Articulated designs allow motion between the foot andhank that occurs around an articulation in the region cor-esponding to the anatomic ankle. There are two variationsf articulated design: single axis and multiple axis. Singlexis (Fig. 3B) includes a transverse ankle axis that permitshe foot to go into plantar flexion and dorsiflexion, with allotion taking place around a single axis. As the foot plan-

ar flexes, a posterior bumper (a synthetic rubber in a cy-indrical shape posterior to the ankle axis) is compressed,esisting the motion. The action of the compressed bumperimulates the action of the dorsiflexors of the native foot. Inhe opposite direction, the motion is resisted by the dorsi-lexion bumper, which is positioned anterior to the anklexis. Multiple-axis prosthetic feet (Fig. 3C) permit move-ents in any direction: plantar flexion, dorsiflexion, inver-

ion, eversion, and a slight amount of rotation around aertical axis. This type of prosthetic feet accommodates toneven walking surfaces and absorbs some of the torsionalorces created in walking, reducing torque to the limb byhe socket. Although there is greater latitude, the increasedotion may create instability in patients with marginal

oordination. An increase in function comes at the cost of
n increase in size and weight, and may require more main-

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enance. Newer versions are now fabricated of carbon com-osite structures to reduce weight.Prosthetic feet are predominantly designed for walking,

ut many young and active lower limb amputees have ex-ressed the need to be more active, resulting in a neweneration of prosthetic feet (energy storing feet, Fig. 3D).ut there are vast differences between force vectors foralking and running. During running, there is a period of

ree flight and a downward force at heel contact that ex-eeds the body weight two to three times. In walking, thisorce barely exceeds body weight.55 The energy storing feetncorporate a shock absorption mechanism in the form of alexible keel that stores energy to be used during toe off. Asn amputee’s cadence increases, the amount of time on theeel will decrease, and the amount of time on the forefootill increase. More time on the forefoot will increase the

orce exerted to the forefoot, causing an increase in theorsiflexion moment. Since the design of new materials,uch as graphite composite, Delrin (DuPont), KevlarDuPont), polyurethane elastomers, and flexible rubbers,he dorsiflexion moment allows the keel to compress, ab-orbing energy, which, during push-off, is released and aidsn propelling the amputee’s limb forward. In addition tohe energy storing and releasing capabilities, the feet allow

Figure 3. (A) SACH (solid ankle cushion heel) foot (CouOhio Willow Wood). (C) Poly axis foot. (D) LP Vari Flex

more fluid motion, which produces a more normal gait. u

oot amputationsidfoot and transmetatarsal amputations are typically per-

ormed for digital gangrene, osteomyelitis of the forefoot,r nonhealing ulcerations of the forefoot. Acute infection issually stabilized before primary closure, so midfoot orransmetatarsal amputations are often performed as stagedrocedures. The technique of maintaining a smooth meta-arsal or midfoot parabola and beveling the distal osseustructure lessens the likelihood of ulceration postopera-ively from excessive pressure once the patient begins reha-ilitation and ambulating. Custom molded shoes and in-

ays, which off-load and support excessive pressure areas,re often prescribed postoperatively once the patient hasompletely healed the amputation. Often, recurrent prob-ems are avoided with a well constructed shoe and inlay.he more proximal the amputation, the more tendon in-

ertions are at risk, which could result in an acquired equi-as or varus deformity as a result of a tendonous imbalance

f the tendons are sacrificed. These acquired deformitiesnd any osseous prominence often result in pressure pointseading to ulceration. Acquired equinas deformities withimited ankle dorsiflexion and subsequent plantar ulcer-tion of the forefoot respond well to an Achilles tendonengthening, reducing the forefoot pressure associated with

of Ohio Willow Wood). (B) Single axis foot (courtesy of(courtesy of Ossur).

rtesy

lceration. Partial foot amputations are limb salvage pro-

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edures that avoid more disabling energy inefficient highereg amputation. Patients with foot amputations consumeess energy in ambulation than individuals with more prox-mal leg amputations.56 Cardiac function and oxygen con-umption after midfoot, Syme’s, below-, through-, andbove-knee amputations are directly related to the level ofmputation. In addition, the ability to walk long or shortistances is decreased in patients with more proximal am-utations.30 Transmetatarsal and midfoot amputations are

imb salvage procedures, preserving the extremity and al-owing the patient to expend less energy throughout theait cycle.57,58

rostheticsn the management of partial foot amputations, the devices, at times, referred to as a “prosthosis,” which is a combi-ation of a prosthesis and an orthosis. Many prosthosisesigns include principles that are used in the fabricationnd design of a foot orthosis, ankle foot orthosis, and lowerimb prosthesis. With all levels of amputation, a number ofactors are assessed in determining the proper prosthosis.irst, the amputee’s ability to control the joints and muscleunction of the foot and ankle must be evaluated. Musclembalance and joint instability or deformity, either fixed ororrectable, should also be assessed. Skin integrity and sen-itivity and the level of scar adhesion must be evaluated andaken into account when determining the prosthosis designnd material composition. The patient’s weight bearingbility is assessed as well. Finally, the patient’s goals andspirations with regard to activity level and cosmetics of therosthosis must be considered.A transmetatarsal amputation eliminates the entire nor-al forefoot load-bearing capacity. This means that it is no

onger practical to transfer the total forefoot ground reac-ion force used during midstance to terminal stance ontohe plantar surface of the residual foot.59 Prosthetic designsor this level of amputation attempt to correct this and areimilar to the molded inner sole (foot orthotic), with theddition of a forefoot filler. This type of design serves toaintain the correct relation between the residual foot and

he patient’s shoe. To assist in reducing the increased fore-oot ground reaction force, a full length carbon graphitelate is placed under the toe filler. Shoe modifications, suchs the addition of a rocker sole, with its apex proximal tohe amputation site, can further reduce the plantar surfaceressure onto the residual limb.Tarsometatarsal and midtarsal amputations have func-

ional limitations similar to those of transmetatarsal ampu-ation. The reduced surface area makes the task of interfac-ng a prosthosis to the residual limb even more difficultith the absence of push-off at the end of stance phase,
hich compromises the quality of gait. The prosthosis for p
his more proximal level of amputation requires a higherupportive design, typically proximal to the ankle joint,hich allows a ground reaction force to imitate the sense ofush-off for the patient. One model incorporates an ankleoot orthosis incorporated with a forefoot filler. This designay also be used for nonamputees with inadequate plantar

lexion strength, allowing dorsiflexion resistance at the endf the stance phase, leading to a sense of push-off. Arosthosis based with the rigid ankle foot orthosis designrevents dorsiflexion by blocking the ankle joint motion athe appropriate angle. The socket interface resists dorsiflex-on anteriorly, effectively blocking this motion, which al-ows a more energy efficient gait cycle.56 A prosthosis con-tructed with an anterior shell and a posterior opening isore functional than the posterior shell ankle foot orthosis

esign. Some modern designs incorporate a full length en-rgy storing footplate of carbon composite with a strutxtending to an anterior shell (Fig. 4A). Other designs usehigh anterior shell and a carbon composite footplate withfoam material creating the desired foot shape (Fig. 4B).Silicone prosthetics were originally introduced to pro-

ide superior cosmetic appearance (Fig. 5A). Silicone pros-heses have also proved successful for amputees with fragilekin and adherent scar tissue. A silicone prosthesis allowsor successful restoration of balance and a more normalait, if sufficiently reinforced to obtain a degree of rigid-ty required for the patient’s activity level. In all patients,comfortable socket, a balanced foot, and an optimal

ait pattern are the objectives for users of partial foot

igure 4. (A) Ossur AFO Dynamic (courtesy of Ossur). (B) Partial footrosthesis (courtesy of Custom Composite).

rosthetics.

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igital and ray amputations with partial foot amputations, the goal of digital or

ay amputation is to maintain a functional foot thatllows the patient to ambulate with as little energy asossible. The digital amputation can be performed athree different levels: the distal interphalangeal jointdistal Syme’s), proximal interphalangeal joint, or meta-arsalphalangeal joint. The ray amputation, either par-ial or complete, is performed to the level of uninvolvedone, which may require a resection of the entire ray.esection of the entire first or fifth ray often leads to

endon imbalances and acquired deformities with newressure points as opposed to central ray amputations.he digital and ray amputations are extremely func-

ional, with few complications, in patients with ade-

Figure 5. (A) Partial foot silicone prosthesis (courtesyprovided by Alternative Prosthetics.

uate healing potential. w

rostheticshe consequence of amputation of one or more toes is a

unctional reduction in the forefoot load-bearing areas.igital amputation can lead to increased pressure at theetatarsal head level from transverse deviation of the adja-

ent digits, leading to an instability at the metatarsalpha-angeal joint and resulting in a more prominent metatarsalead. The increased pressure is greatest when the hallux ismputated. In normal gait, loss of a digit is not a functionalroblem. But at higher activities levels, the loss of the hal-

ux creates difficulties that result from the loss of activeush-off. Most prosthetics for toe amputations consist of aoe filler. The toe filler’s function is to maintain properhape and prevent deformation in the shoe.Toe fillers rangerom simply packing material placed in the shoe (ie, lamb’s

lternative Prosthetics). (B) Silicone “filler” prosthesis
of A
ool) to a modified foot orthotic made of silicone or foam

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Fig. 5B). Toe spacers also prevent deviation of the otheroes in the transverse plane and offer excellent cosmesisFig. 5), which can have a psychological benefit for theatient.

erspectivepproximately 75% of AKAs and BKAs occur in patientsged 65 or older. In this elderly population, arteriosclerosisccounts for 90% of amputations.60 Amputees with pe-ipheral vascular disease are often already operating at ap-roximately 80% of maximal capacity during “normal”alking pace. So there is a greatly decreased reserve for

ncreasing their level of activity. At successively higher lev-ls of amputation, the walking speed decreases, with anccompanying increase in oxygen and energy consump-ion. The result is a severe limitation of ambulation andctivity level, translating into decreased walking speed andistance.30

EFERENCES

1. Sanders GT. Amputation prosthetics. Philadelphia, PA: FADavis Company; 1986.

2. Padula PA, Friedmann LW. Acquired amputation and prosthesesbefore the sixteenth century. Angiology 1987;38:133–141.

3. Friedmann LW. The psychological rehabilitation of the ampu-tee. Springfield, IL: Charles C Thomas; 1978.

4. Boyd HB. Anatomic disarticulation of the hip. Surg GynecolObstet 1947;84:346–349.

5. Slocum DG. An atlas of amputation. St Louis, MO: CV MosbyCo; 1949.

6. Sugarbaker PH, Chretien PB. A surgical technique for hip dis-articulation. Surgery 1981;90:546–553.

7. Unruh T, Fisher DF, Unruh TA, et al. Hip disarticulation. An11-year experience. Arch Surg 1990;125:791–793.

8. Dénes Z, Till A. Rehabilitation of patients after hip disarticula-tion. Arch Orthoped Trauma Surg 1997;116:498–499.

9. Endean ED, Schwarcz TH, Barker DE, et al. Hip disarticula-tion: factors affecting outcome. J Vasc Surg 1991;14:398–404.

0. László G, Kullmann L. Hip disarticulation in peripheral vasculardisease. Arch Orthoped Trauma Surg 1987;106:126–128.

1. Kullmann L, László G, Kállay M, Borsay J. Lábszár amputációvalszerzett tapasztalataink. Orv Hetil 1982;23:2051–2055.

2. Chin T, Sawamura S, Shiba R, et al. Energy expenditure duringwalking in amputees after disarticulation of the hip. J Bone JointSurg 2005;87:117–119.

3. Traugh GH, Corcoran PJ, Reyes RL. Energy expenditure ofambulation in patients with above-knee amputations. ArchPhysical Med Rehab 1975;56:67–71.

4. Zaffer SM, Braddom RL, Conti A, et al.Total hip disarticulationprosthesis with suction socket: report of two cases. Am J PhysicalMed Rehab 1999;78:160–162.

5. Nowroozi F, Salvanelli ML, Gerber LH. Energy expenditure inhip disarticulation and hemipelvectomy amputees. Arch Physi-cal Med Rehab 1983;64:300–303.

6. Nietert M, Englisch N, Kreil P, Alba-Lopez G. Loads in hipdisarticulation prostheses during normal daily use. Prosthetics
Orthotics Int 1998;22:199–215.
7. Huang CT. Energy cost of ambulation with Canadian hip dis-articulation prosthesis. JAMA Alabama 1983;47–48.

8. Gosheger G, Hillmann A, Rödl R, et al. Stump lengthening afterhip disarticulation using a modular endoprosthesis in 5 patients.Acta Orthopedica Scandinavica 2001;72:533–536.

9. Waters RL, Perry J, Antonelli D, Hislop H. Energy cost ofwalking of amputees: the influence of level of amputation.J Bone Joint Surg 1976;58:42–46.

0. Michael JW. Modern prosthetic knee mechanisms. Clin Or-thoped Related Res 1999;361:39–47.

1. Buckley JG, Spence WD, Solomonidis SE. Energy cost of walk-ing: Comparison of “intelligent prosthesis” with conventionalmechanism. Arch Physical Med Rehab 1997;78:330–333.

2. Murray MP, Mollinger LA, Sepic SB, et al. Gait patterns inabove-knee amputee patients: Hydraulic swing control vsconstant-friction knee components. Arch Physical Med Rehab1983;64:339–345.

3. Isakov E, Susak Z, Becker E. Energy expenditure and cardiacresponse in above knee amputation while using prosthesis withopen and locked knee mechanisms. Scand J Rehab Med 1985;12:108–111.

4. Taylor MB, Clark E, Offord EA, Baxter C. A comparison ofenergy expenditure by a high level trans-femoral amputee usingthe intelligent prosthesis and conventionally damped prostheticlimbs. Prosthetics Orthotics Int 1996;20:116–121.

5. Pinzur MS, Bowker JH. Knee disarticulation. Clin OrthopedRelated Res 1999;361:23–28.

6. Schuch CM, Pritham CH. Current transfemoral sockets. ClinOrthoped Related Res 1999;361:48–54.

7. Burgess EM. Sites of amputation election according to modernpractice. Clin Orthoped Related Res 1964;37:17–22.

8. Barnes RW, Shanik GD, Slaymaker EE. An index of healing inbelow knee amputations. Leg blood pressure by Doppler ultra-sound. Surgery 1976;79:13–20.

9. Burgess E, Matsen R, Wyss C, Simmons C. Segmental transcu-taneous measurements of PO2 in patients requiring below theknee amputation for peripheral vascular insufficiency. J BoneJoint Surg 1982;64A:378–382.

0. Pinzur MS, Gold J, Schwartz D, et al. Energy demands forwalking in dysvascular amputees as related to level of amputa-tion. Orthopedics 1992;15:1033–1037.

1. Gonzalez EG, Corcoran PJ, Reyes RI. Energy expenditure inbelow-knee amputees: correlation with stump length. ArchPhysical Med Rehab 1974;55:111–119.

2. Fletcher DD, Andrews KL, Butters MA, et al. Rehabilitation ofthe geriatric vascular amputee patient: A population based study.Arch Physical Med Rehab 2001;82:776–779.

3. Moore TJ, Barron J, Hutchinson F III, et al. Prosthetic usagefollowing major lower extremity amputation. Clin OrthopedRelated Res 1989;238:219–224.

4. Francis W, Renton CJC. Mobility after major limb amputationfor arterial occlusive disease. Prosthetics Orthotics Int 1987;11:85–89.

5. Robinson K. Amputation in vascular disease. Ann Royal CollSurg Eng 1980;62:87–91.

6. Haynes IG, Middleton MD. Amputation for peripheral vasculardisease: experience of a district general hospital. Ann Royal CollSurg Eng 1981;63:342–344.

7. Bowker JH, Sam Giovanni TP, Pinzur MS. North Americanexperience with knee disarticulation with use of a posterior myo-
cutaneous flap. J Bone Joint Surg 2000;82-A:1571–1574.

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3

4

4

4

4

4

4

4

4

4

4

5

5

5

5

5

5

5

5

5

5

6


8. Kistinsson O. The ICEROSS concept: a discussion of a philos-ophy. Prosthetics Orthotics Int 1993;17:49–55.

9. Pinzur MS, Slosar PJ Jr, Reddy NK, Osterman H. Through-knee amputation in peripheral vascular insufficiency: functionaloutcome. Contemp Orthoped 1992;24:157–160.

0. Baumgartner R. Failures in through-knee amputation. Prosthet-ics Orthotics Int 1983;7:116–118.

1. Corcoran PJ, Brengelmann GL. Oxygen uptake in normal andhandicapped subjects, in relation to speed of walking besidevelocity-controlled cart. Arch Physical Med Rehab 1970;3:78–87.

2. Hoffman AD, Sheldahl LM, Buley KJ, Sandford PR. Physiolog-ical comparison of walking among bilateral above-knee amputeeand able-bodied subjects, and a model to account for the differ-ences in metabolic cost. Arch Physical Med Rehab 1974;78:385–392.

3. Abrahamson MA, Skinner HB, Effeney DJ, Wilson LA. Pre-scription options for the below knee amputee. A review. Ortho-pedics 1985;8:210–220.

4. Campbell WB, St Johnson JA, Kernick VF, Rutter EA. Lowerlimb amputation: striking the balance. Ann Royal Coll Surg Eng1994;76:420–421.

5. Hirai M, Tokuhiro A, Takechi H. Stump problems in traumaticamputation. Acta Med Okayama 1993;47:407–412.

6. Hachisuka K, Dozono K, Ogata H, et al. Total surface bearingbelow-knee prosthesis: Advantages, disadvantages, and clinicalimplications. Arch Physical Med Rehab 1998;79:783–789.

7. Cappa AJ. The below-knee bypass prosthesis. J Orthotists Pros-thetists 1992;4:166–170.

8. Weiss M, Gielzynski A, Wirski J. Myoplasty immediate fittingambulation. (Reprint of paper presented at the sessions of theWorld Commission on Research in Rehabiliation, 10th WorldCongress of the International Society, Wiesbaden, Germany,September, 1966).

9. Burgess EM, Romano RL. The management of lower extremity

amputees using immediate postsurgical prostheses. ClinOrthoped Related Res 1968;57:137–156.

0. Kane TJ, Pollack EW. The rigid versus soft postoperative dress-ing controversy: a controlled study in vascular below knee am-putees. Am Surg 1980;46:244–247.

1. Cohen SI, Goldman LD, Salzman EW, Glotzer ND. The dele-terious effect of immediate postoperative prosthesis in belowknee amputations for ischemic disease. Surgery 1974;76:992–1001.

2. Weinstein ES, Livingston S, Rubin JR. The immediate postop-erative prosthesis (IPOP) in ischemia and septic complications.Am Surg 1988;4:386–389.

3. Falsom D, King T, Rubin JR. Lower-extremity amputation withimmediate postoperative prosthetic placement. Am J Surg 1992;164:320–322.

4. Schon LC, Short KW, Soupiou O, et al. Benefits of early pros-thetic management of transtibial amputees: A prospective clin-ical study of a prefabricated prosthesis. Foot Ankle Int 2002;23:509–514.

5. Hittenberger, Drew A. The Seattle foot. Orthotics Prosthetics1986;40:17–23.

6. Waters RL, Perry J, Antonelli D, et al. Energy cost of walkingamputees: the influence of level of amputation. J Bone JointSurg 1976;58:42–46.

7. Sanders, LJ. Transmetatarsal and midfoot amputations. ClinPodiatric Med Surg 1997;14:741.

8. Sage R, Pinzur MS, Cronin R, P HF, Osterman H. Complica-tions following midfoot amputation in neuropathic and dysvas-cular feet. JAPMA 1989;79:277.

9. Kelly VE, Mueller MJ, Sinacore DR. Timing of peak plantarpressure during the stance phase of walking: A study of patientswith diabetes mellitus and transmetatarsal amputation. J AmPodiatr Med Assoc 2000;90:18–23.

0. Clark SC, Blue B, Bearer JB. Rehabilitation of the elderly am-
putee. J Am Geriatric Soc 1983;31:439–448.

Documents

Let Them Walk! Current Prosthesis Options for Leg and Foot Amputees