66. DeRubertis BG, Pierce M, Chaer RA, et al. Lesion severity and treatment complexity are associated

with outcome after percutaneous infra-inguinal intervention. J Vasc Surg 2007;46:709–716.

67. Schanzer A, Hevelone N, Owens CD, et al. Technical factors affecting autogenous vein graft failure:

observations from a large multicenter trial. J Vasc Surg 2007;46:1180–1190; discussion 1190.

68. Robinson WP 3rd, Owens CD, Nguyen LL, et al. Inferior outcomes of autogenous infrainguinal

bypass in Hispanics: an analysis of ethnicity, graft function, and limb salvage. J Vasc Surg

2009;49:1416–1425.

69. Conte MS. Critical appraisal of surgical revascularization for critical limb ischemia. J Vasc Surg

2013;57:8S–13S.

70. Rogers RK, Dattilo PB, Garcia JA, et al. Retrograde approach to recanalization of complex tibial

disease. Catheter Cardiovasc Interv 2011;77:915–925.

71. Markose G, Bolia A. Below the knee angioplasty among diabetic patients. J Cardiovasc Surg

2009;50:323–329.

72. Pentecost MJ, Criqui MH, Dorros G, et al. Guidelines for peripheral percutaneous transluminal

angioplasty of the abdominal aorta and lower extremity vessels. a statement for health

professionals from a Special Writing Group of the Councils on Cardiovascular Radiology,

Arteriosclerosis, Cardio-Thoracic and Vascular Surgery, Clinical Cardiology, and Epidemiology and

Prevention, the American Heart Association. J Vascu Interv Radiol 2003;14:S495–S515.

73. Srodon P, Matson M, Ham R. Contrast nephropathy in lower limb angiography. Ann R Coll Surg

Engl 2003;85:187–191.

74. Berkseth RO, Kjellstrand CM. Radiologic contrast-induced nephropathy. Med Clin North Am

1984;68:351–370.

75. Kandzari DE, Rebeiz AG, Wang A, et al. Contrast nephropathy : an evidence-based approach to

prevention. Am J Cardiovasc Drugs 2003;3:395–405.

76. MacNeill BD, Harding SA, Bazari H, et al. Prophylaxis of contrast-induced nephropathy in patients

undergoing coronary angiography. Catheter Cardiovasc Interv 2003;60:458–461.

77. Knight CG, Healy DA, Thomas RL. Femoral artery pseudoaneurysms: risk factors, prevalence, and

treatment options. Ann Vasc Surg 2003;17:503–508.

78. Lonn L, Olmarker A, Geterud K, et al. Prospective randomized study comparing ultrasound-guided

thrombin injection to compression in the treatment of femoral pseudoaneurysms. J Endovasc Ther

2004;11:570–576.

79. Quinn SF, Kim J. Percutaneous femoral closure following stent-graft placement: use of the perclose

device. Cardiovasc Intervent Radiol 2004; 27:231–236.

80. Muradin GS, Bosch JL, Stijnen T, et al. Balloon dilation and stent implantation for treatment of

femoropopliteal arterial disease: meta-analysis. Radiology 2001;221:137–145.

81. Laird JR, Katzen BT, Scheinert D, et al. Nitinol stent implantation vs. balloon angioplasty for

lesions in the superficial femoral and proximal popliteal arteries of patients with claudication:

three-year follow-up from the RESILIENT randomized trial. J Endovasc Ther 2012;19:1–9.

82. Schillinger M, Sabeti S, Loewe C, et al. Balloon angioplasty versus implantation of nitinol stents in

the superficial femoral artery. N Engl J Med 2006;354:1879–1888.

83. Vraux H, Hammer F, Verhelst R, et al. Subintimal angioplasty of tibial vessel occlusions in the

treatment of critical limb ischaemia: mid-term results. Eur J Vasc Endovasc Surg 2000;20:441–446.

84. Bosiers M, Hart JP, Deloose K, et al. Endovascular therapy as the primary approach for limb

salvage in patients with critical limb ischemia: experience with 443 infrapopliteal procedures.

Vascular 2006;14:63–69.

85. Randon C, Jacobs B, De Ryck F, et al. Angioplasty or primary stenting for infrapopliteal lesions:

results of a prospective randomized trial. Cardiovasc Intervent Radiol 2010;33:260–269.

86. Conte MS, Geraghty PJ, Bradbury AW, et al. Suggested objective performance goals and clinical

trial design for evaluating catheter-based treatment of critical limb ischemia. J Vasc Surg

2009;50:1462–1473 e1–e3.

87. Adam DJ, Beard JD, Cleveland T, et al. Bypass versus angioplasty in severe ischaemia of the leg

(BASIL): multicentre, randomised controlled trial. Lancet 2005;366:1925–1934.

88. Holm J, Arfvidsson B, Jivegard L, et al. Chronic lower limb ischaemia. a prospective randomised

controlled study comparing the 1-year results of vascular surgery and percutaneous transluminal

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angioplasty (PTA). Eur J Vasc Surg 1991;5:517–522.

89. van der Zaag ES, Prins MH, Jacobs MJ. [Treatment of intermittent claudication; prospective

randomized study in the BAESIC-Trial (bypass, angioplasty or endarterectomy patients with severe

intermittent claudication)]. Ned Tijdschr Geneeskd 1996;140:787–788.

90. Wolf GL, Wilson SE, Cross AP, et al. Surgery or balloon angioplasty for peripheral vascular disease:

a randomized clinical trial. Principal investigators and their Associates of Veterans Administration

Cooperative Study Number 199. J Vasc Interv Radiol 1993;4:639–648.

91. Bradbury AW, Adam DJ, Bell J, et al. Bypass versus angioplasty in severe ischaemia of the leg

(BASIL) trial: a survival prediction model to facilitate clinical decision making. J Vasc Surg

2010;51:52S-68S.

92. Nolan BW, De Martino RR, Stone DH, et al. Prior failed ipsilateral percutaneous endovascular

intervention in patients with critical limb ischemia predicts poor outcome after lower extremity

bypass. J Vasc Surg 2011;54:730–735; discussion 735–736.

93. Malone JM, Goldstone J, Moore WS. Autogenous profundaplasty: the key to long-term patency in

secondary repair of aortofemoral graft occlusion. Ann Surg 1978;188:817–823.

94. Reed AB, Conte MS, Belkin M, et al. Usefulness of autogenous bypass grafts originating distal to the

groin. J Vasc Surg 2002;35:48–54; discussion, 54–55.

95. Schanzer A, Owens CD, Conte MS, et al. Superficial femoral artery percutaneous intervention is an

effective strategy to optimize inflow for distal origin bypass grafts. J Vasc Surg 2007;45:740–743.

96. Veith FJ, Gupta SK, Ascer E, et al. Six-year prospective multicenter randomized comparison of

autologous saphenous vein and expanded polytetrafluoroethylene grafts in infrainguinal arterial

reconstructions. J Vasc Surg 1986;3:104–114.

97. Rosenthal D. Endoscopic in situ bypass. Surg Clin North Am 1995;75:703–713.

98. Eid RE, Wang L, Kuzman M, et al. Endoscopic versus open saphenous vein graft harvest for lower

extremity bypass in critical limb ischemia. J Vasc Surg 2014;59:136–144.

99. Bandyk DF, Johnson BL, Gupta AK, et al. Nature and management of duplex abnormalities

encountered during infrainguinal vein bypass grafting. J Vasc Surg 1996;24:430–436; discussion

437–438.

100. Gilbertson JJ, Walsh DB, Zwolak RM, et al. A blinded comparison of angiography, angioscopy, and

duplex scanning in the intraoperative evaluation of in situ saphenous vein bypass grafts. J Vasc Surg

1992;15:121–127; discussion 127-129.

101. Conte MS, Belkin M, Upchurch GR, et al. Impact of increasing comorbidity on infrainguinal

reconstruction: a 20-year perspective. Ann Surg 2001; 233:445–452.

102. Fogle MA, Whittemore AD, Couch NP, et al. A comparison of in situ and reversed saphenous vein

grafts for infrainguinal reconstruction. J Vasc Surg 1987;5:46–52.

103. Taylor LM Jr, Edwards JM, Porter JM. Present status of reversed vein bypass grafting: five-year

results of a modern series. J Vasc Surg 1990;11:193–205; discussion 205–206.

104. Hall KV. The great saphenous vein used in situ as an arterial shunt after extirpation of the vein

valves. a preliminary report. Surgery 1962;51:492–495.

105. Leather RP, Powers SR, Karmody AM. A reappraisal of the in situ saphenous vein arterial bypass:

its use in limb salvage. Surgery 1979;86:453–461.

106. Donaldson MC, Mannick JA, Whittemore AD. Femoral-distal bypass with in situ greater saphenous

vein. long-term results using the Mills valvulotome. Ann Surg 1991;213:457–464; discussion 464–

465.

107. Moody AP, Edwards PR, Harris PL. In situ versus reversed femoropopliteal vein grafts: long-term

follow-up of a prospective, randomized trial. Br J Surg 1992;79:750–752.

108. Wengerter KR, Veith FJ, Gupta SK, et al. Prospective randomized multicenter comparison of in situ

and reversed vein infrapopliteal bypasses. J Vasc Surg 1991;13:189–197; discussion 197–199.

109. Panetta TF, Marin ML, Veith FJ, et al. Unsuspected preexisting saphenous vein disease: an

unrecognized cause of vein bypass failure. J Vasc Surg 1992;15:102–110; discussion 110–112.

110. Marcaccio EJ, Miller A, Tannenbaum GA, et al. Angioscopically directed interventions improve arm

vein bypass grafts. J Vasc Surg 1993;17:994–1002; discussion 1003-1004.

111. Whittemore AD, Kent KC, Donaldson MC, et al. What is the proper role of polytetrafluoroethylene

grafts in infrainguinal reconstruction? J Vasc Surg 1989;10:299–305.

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112. Quinones-Baldrich WJ, Prego AA, Ucelay-Gomez R, et al. Long-term results of infrainguinal

revascularization with polytetrafluoroethylene: a ten-year experience. J Vasc Surg 1992;16:209–217.

113. Miller JH, Foreman RK, Ferguson L, et al. Interposition vein cuff for anastomosis of prosthesis to

small artery. Aust N Z J Surg 1984;54:283–285.

114. Chew DK, Owens CD, Belkin M, et al. Bypass in the absence of ipsilateral greater saphenous vein:

safety and superiority of the contralateral greater saphenous vein. J Vasc Surg 2002;35:1085–1092.

115. Sarac TP, Huber TS, Back MR, et al. Warfarin improves the outcome of infrainguinal vein bypass

grafting at high risk for failure. J Vasc Surg 1998;28:446–457.

116. Creager MA. Medical management of peripheral arterial disease. Cardiol Rev 2001;9:238–245.

117. Veith FJ, Weiser RK, Gupta SK, et al. Diagnosis and management of failing lower extremity arterial

reconstructions prior to graft occlusion. J Cardiovasc Surg 1984;25:381–384.

118. Bandyk DF, Schmitt DD, Seabrook GR, et al. Monitoring functional patency of in situ saphenous

vein bypasses: the impact of a surveillance protocol and elective revision. J Vasc Surg 1989;9:286–

296.

119. Santo VJ, Dargon PT, Azarbal AF, et al. Open versus endoscopic great saphenous vein harvest for

lower extremity revascularization of critical limb ischemia. J Vasc Surg 2014;59:427–434.

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Chapter 94

Lower Extremity Amputation

Matthew J. Sideman, Kevin E. Taubman, and Bradley D. Beasley

Key Points

1 The annual incidence of amputations is decreasing.

2 The vast majority of lower extremity amputations are performed for complications of diabetes or

arterial insufficiency.

3 Emergent amputation is indicated in the face of uncontrolled or ascending infection.

4 Primary amputation is occasionally indicated in cases of treatment for lower extremity trauma.

5 Revascularization is often performed in conjunction with a minor amputation, either simultaneously

or as a staged procedure.

6 The choice of amputation level depends on the indication for the procedure, the condition of the

patient, and the rehabilitation potential of the patient.

7 The energy required to ambulate following a lower extremity amputation increases with ascending

level of amputation.

1 Surgeons are often involved in treating patients requiring lower extremity amputation. Increasing

incidence of diabetes, peripheral arterial disease, and the aging population has put more patients at risk

for amputation. The explosion of endovascular interventions over the past decade has resulted in

decreasing numbers of amputations performed annually.1 A review of the Nation Hospital Discharge

Survey and Medicare claims data confirms this negative trend.2 Clinical judgment is critical to a

successful outcome. Factors to consider are primary amputation, revascularization, repeat

revascularization, level of amputation, and timing of amputation. The surgeon must remember that the

goal is to maintain maximal function of the patient not necessarily maximal length of the limb.

Consequently, experience of the surgeon has been shown to be key to a successful outcome.3

INDICATIONS

2 Most lower extremity amputations are performed for complications of diabetes or arterial

insufficiency (Table 94-1). Chronic infection and trauma account for less than 10% of the total number

of amputations. Other indications include neuroma, frostbite, malignancy, chronic pain, arterial

embolization, venous insufficiency, and cryoglobulinemia.4

Elective lower extremity amputation in diabetic and vascular patients is indicated for gangrene (dry

gangrene), gangrene with infection (wet gangrene), unremitting and unreconstructable rest pain, and

nonhealing ulcers. The goal of the operation is to remove all nonviable tissue, relieve ischemic rest

pain, ensure primary wound healing, and facilitate rehabilitation. Elective amputation should only be

performed following an evaluation for revascularization procedure by a surgeon capable of performing

such procedures. Veith et al.5 reported that 96% of patients who underwent lower extremity

arteriography for limb-threatening infrainguinal arteriosclerosis were candidates for arterial

reconstruction. Advances in percutaneous management have expanded treatment options to patients

who were not otherwise operative candidates. Not all patients are candidates for arteriography,

including those with chronic renal insufficiency, organic brain syndrome, nonfunctional limbs, fixed

joint contractures, insensate feet, and those with extensive gangrene.

Spinal cord stimulation (SCS) may offer a chance for limb salvage for patients with chronic ischemia

in whom reconstruction is not an option. Based on Melzack and Wall theory for the treatment of chronic

pain,6 the mechanism of pain relief and increased blood flow in end-stage peripheral vascular disease is

unclear. Despite this, there is peripheral vasodilatation on the microvascular level which leads to pain

relief,7 increased claudication distance,8 ulcer healing,9 and possible limb salvage.7,10,11 The 1-year foot

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salvage rate is 60% to 70% on average, according to a review of the literature.12 SCS is only

appropriate when surgery for revascularization is no longer possible. Furthermore, SCS only dilates

microvasculature and does nothing for the underlying, progressive peripheral vascular disease that is

causing the ischemia. SCS, therefore, is only a temporizing measure, but can potentially give an

extended functional period with a procedure that is well tolerated and relatively simple to perform.12

Recently, Gersbach et al. have shown that the benefits of SCS persist longer than initially thought.13

3 Emergent amputation is indicated in the face of uncontrolled or ascending infection. In the case of

uncontrolled sepsis, it can even be a life-saving maneuver. A diabetic patient with a foot abscess is a

surgical emergency. Frequently, incision and drainage with or without a toe or a combined toe and

metatarsal resection is sufficient to control the acute problem. The wounds should be left open in the

setting of acute infection. If the process extends beyond the foot, a staged amputation should be

performed proximal enough to control the infection. This can include an ankle disarticulation, a

guillotine below-knee amputation (BKA), a knee disarticulation, or a guillotine above-knee amputation

(AKA). Disarticulations have the advantage of preserving limb length and avoiding an open bone in the

incision. After the infection is controlled, the appropriate amputation can be completed. A one-stage

primary AKA can be considered in patients who are nonambulatory, have infection involving the entire

lower leg, have a fixed knee contracture, or those with a nonfunctional limb. Patients who are too

unstable for surgery can be temporized with a cryoamputation.14

INDICATIONS/CONTRAINDICATIONS

Table 94-1 Indications for Lower Extremity Amputation

4 Primary amputation is occasionally indicated as treatment for severe lower extremity trauma. Both

penetrating and blunt injuries of the lower extremities are frequently associated with vascular, nerve,

bone, and extensive soft tissue injuries. Several treatment guidelines have been developed for lower

extremity trauma. Lange15 recommended primary amputation for open tibial fractures with associated

vascular injuries if the posterior tibial nerve was disrupted in an adult or if the duration of warm

ischemia was greater than 6 hours in a crush injury. In addition, he suggested that primary amputation

was relatively indicated in patients with polytrauma, severe ipsilateral foot injuries, and in those with

an expected protracted postoperative course. These suggestions are supported in work by Bosse et al.16

demonstrating, in the case of high-energy lower extremity trauma, amputation, and reconstruction have

equal functional outcomes at 2 years. Additional guidelines have been provided by Johansen et al.17

who devised a Mangled Extremity Severity Score to predict the need for amputation based on the extent

of skeletal or soft tissue damage, limb ischemia, shock, and age. Unfortunately, none of these guidelines

are predictive of functional recovery in patients who undergo limb salvage.18 Therefore, treatment with

primary amputation is an extremely difficult decision and requires extensive clinical judgment as well as

multidisciplinary input. Contributing factors include the severity of the injury, the overall clinical status,

and the ultimate rehabilitation potential of the patient.

EVALUATION FOR REVASCULARIZATION

Modern vascular surgery techniques allow successful limb salvage in situations not previously possible.

All patients who present for possible lower extremity amputation, including minor amputations, should

have their peripheral vascular circulation evaluated preoperatively. Any patient with absent pedal

pulses or abnormal ankle–brachial indices should be evaluated by a vascular surgeon skilled in both

open and endovascular revascularization techniques. The evaluation may require only a thorough

2674

history and physical examination if there is an obvious contraindication to revascularization (e.g.,

nonfunctional limb, severe organic brain syndrome). Noninvasive vascular laboratory examinations are

a mandatory minimum for patients with abnormal vascular examinations. Additional imaging with

either multiple-slice computed tomographic angiography (CTA), magnetic resonance angiography

(MRA), or contrast angiography can be done based upon the patient’s initial evaluation and vascular lab

results. The information obtained from these tests is heavily dependent on the quality of the machinery,

the skill of the technologist, and the knowledge of the interpreting physician. All of these factors must

be taken into account when deciding which test to order. Contrast angiography with selective lower

extremity injections may be necessary to fully define the patient’s anatomy and suitability for

reconstruction; however, it is generally preferred to perform this invasive procedure for preoperative

planning or for planned percutaneous intervention. Contrast arteriography should not be considered a

diagnostic examination.

Exponential advances in endovascular techniques have occurred over the past 10 years. These have

found their way into the peripheral circulation and have applicability in limb salvage. Percutaneous

techniques include convention balloon angioplasty, stenting (including balloon expandable, selfexpanding nitinol, and covered stents), cryoplasty, and percutaneous atherectomy (including laser,

directional, and rotational). The BASIL trial showed no significant difference in amputation-free survival

among patients with critical limb ischemia when randomized to open or percutaneous

revascularization.19

In terms of surgical reconstruction, upper extremity20 and cryopreserved cadaver vein21 have

increased the options for conduit in limb salvage situations. Prosthetic grafts with vein cuffs

22,23 provide

other alternatives when appropriate autogenous conduit is not available. More recently, a heparinbonded prosthetic graft has been introduced and early studies show promising results.24 An operation

for limb salvage should never be denied only for lack of conduit.

5 Re vascularization is often performed in conjunction with a minor amputation, either

simultaneously or as a staged procedure. This allows management of the acute problem of sepsis and

the underlying chronic ischemia. Caution must be taken if there is active infection and the only

available conduit is prosthetic for fear of infecting the graft. Amputation with control of infection

followed by revascularization is the more prudent course. In extreme cases, a limited amputation can be

combined with revascularization and a tissue transfer (free or rotational flap) to achieve limb

salvage.25,26

CHOICE OF AMPUTATION LEVEL

General

6 The choice of amputation level depends on the indication for the procedure, the condition of the

patient, and the rehabilitation potential of the patient. The most common amputation levels are

illustrated in Figure 94-1. Because most amputations are performed for complications of diabetes or

arterial insufficiency, the selected level must remove all nonviable, painful tissue, allow primary

healing, and maximize rehabilitation potential. Selection of the amputation level for malignant disease

is dependent on the biologic characteristics of the neoplasm and will not be discussed further.

The general medical condition and the rehabilitation potential of the patient are important factors in

deciding to proceed with amputation and in selecting the appropriate level. If a patient is ambulatory

and independent preoperatively, the level with the greatest likelihood of maintaining function should be

selected. If the patient is not ambulatory or has significant comorbid conditions, the primary woundhealing rate should be the determining factor.

Specific Situations

Aggressive attempts to salvage a distal amputation level are not indicated for patients who are unlikely

to ambulate with a prosthesis.27 For example, patients with fixed joint contractures greater than 15

degrees at the knee or 10 degrees at the hip are unlikely to ambulate with a prosthesis. BKAs are

relatively contraindicated in patients with paraplegia because flexion contractures at the knee can lead

to stump ulceration.

2675

Figure 94-1. Common amputation levels for the lower extremity.

Energy Requirement

7 The energy required to ambulate following a lower extremity amputation increases with ascending

level of amputation. The more proximal the amputation, the less likely a patient will be able to

ambulate postoperatively. Table 94-2 illustrates the increased energy cost of the common lower

extremity amputations. In clinical practice, the most significant increase is between a BKA and an AKA.

Ambulation on an above-knee prosthesis requires the use of muscle groups poorly suited for that

purpose. These increased energy costs are minor issues for young trauma or cancer patients; however,

they represent a considerable obstacle for the older diabetic or vascular patient.

Clinical Assessment

The primary preoperative consideration for wound healing is the status of the skin and muscle blood

flow. Operative technique, the patient’s nutritional status, and the presence of infection also affect

wound healing. Clinical judgment by an experienced surgeon accurately predicts healing of a BKA in

approximately 80% of cases.28 A palpable pulse at the level immediately proximal to the proposed

amputation essentially ensures healing;29 however, the converse is not true. Noninvasive arterial testing

is the most common adjunctive test used to predict healing of a specific amputation level. Its usefulness

is limited when medial sclerosis prevents vessel compression, a condition common in diabetic patients.

Because the digital vessels are often spared from this process, digital pressure readings may be helpful

in this setting. Transcutaneous oxygen measurement has been shown to predict primary healing

although it is less able to predict failure to heal.30,31 It has become more widely available and has

supplanted previous less reliable tests that were more limited in availability. Tables 94-3 to 94-6

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summarize the results of various preoperative tests to predict wound healing for toe, foot and forefoot,

below-knee, and AKAs, respectively.

Table 94-2 Rehabilitation Energy Cost of Amputation at Various Levels

OPERATIVE TECHNIQUE

General Considerations

Diabetic patients who present septic require adequate fluid resuscitation, broad-spectrum antibiotics

(including anaerobic coverage), and an emergent operation. Whereas maintenance of limb length and

function is admirable, control of sepsis and wide débridement of all nonviable tissue are essential and

potentially lifesaving. All patients require atraumatic tissue handling. Avoid forceps on the skin edge.

Excessive skin flaps and dead space are also not desired. Amputations done in the face of active

infection are kept open and treated with dressing changes. Consider delayed primary closure in cases

where perfusion is intact.

RESULTS

Table 94-3 Preoperative Level Selection: Toe Amputation

RESULTS

Table 94-4 Preoperative Level Selection: Foot and Forefoot Amputation

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Postoperatively, the limb is elevated to minimize tissue edema and promote healing. Weight bearing

on the amputation is delayed until healing is assured. This patient population requires effective

prophylaxis against deep venous thrombosis and venous thromboembolism.

Digital and Ray Amputations

Digital amputations are indicated for some severe and irreducible deformities as well as gangrene or

osteomyelitis localized distal to the base of the proximal phalanx. A technique for partial digital

amputation is illustrated in Figure 94-2A. The circumferential or racquet-shaped skin incision is made

over the distal end of the proximal phalanx, and carried down to bone. Nerves and tendons are

transected under tension and allowed to retract. The proximal phalanx is divided with bone shears or

power saw and the transected end smoothed with a rongeur. Soft tissue coverage can be performed with

either medial/lateral flaps or dorsal/plantar flaps depending on skin tension and viability. The wound is

closed only with simple interrupted skin sutures. Judicious use of subcutaneous sutures is advised due to

danger of vascular compromise to the small remaining flaps. Non–weight bearing restrictions or

protected weight bearing on the heel only in a rigid soled postoperative shoe or walking boot until the

wound heals is recommended.

A ray amputation is indicated when the disease process extends to the metatarsal phalangeal joint.

The technique is similar to a digital amputation and is illustrated in Figure 94-2B. A circumferential

incision is made at the base of the involved toe and extended proximally on the dorsum of the foot over

the metatarsal. The incision is extended to bone. The periosteum is cleared circumferentially and the

bone is transected using a power saw at a level that will allow tension-free closure of the wound. In the

case of the first or fifth toe, the incision is extended on the medial or lateral aspect of the foot,

respectively. Care should be taken to bevel the distal metatarsal stump to minimize any prominence

that may lead to skin breakdown with weight bearing or shoe gear wear. Typically the first metatarsal

is beveled from proximal medial to distal lateral and proximal planter to distal dorsal. Metatarsals 2, 3,

and 4 should be beveled from proximal plantar to distal dorsal. The 5th metatarsal is beveled from

proximal lateral to distal medial and proximal plantar to distal dorsal.

In selected cases of neuropathic ulcers, the metatarsal head can be resected leaving the toe intact. A

dorsal longitudinal incision is made over the metatarsal bone and the metatarsal head is resected with a

power saw. Pulsed lavage and careful soft tissue inspection will help guide appropriate care for the

2678

plantar wound (i.e., packing, negative pressure therapy or ellipse of wound with closure). The dorsal

wound is typically closed unless severe infection is encountered.

RESULTS

Table 94-5 Preoperative Level Selection: Below-Knee Amputation

Transmetatarsal Amputation

Transmetatarsal amputation (TMA) is a useful procedure that maintains a patient’s ability to ambulate

without the aid of a prosthesis. It is indicated when the gangrenous or infectious process involves

multiple digits or a portion of the forefoot. Care must be taken to plan for the appropriate soft tissue

coverage if primary closure is desired. Maximizing the plantar flap is most common, but coverage can

also be gained from medial or laterally based flaps and even filleted toe flaps. If adequate soft tissue

coverage is not available and a more proximal foot amputation (i.e., Chopart joint amputation) is not

desired then an open amputation through the metatarsal bones can be performed. The wound is allowed

to close secondarily or covered with a skin graft. Skin grafts in this position, however, are susceptible to

breakdown secondary to the pressure related to ambulation.

RESULTS

Table 94-6 Preoperative Level Selection: Above-Knee Amputation

The technique is demonstrated in Figure 94-3. A skin incision is made on the dorsum of the foot

immediately proximal to the metatarsal heads and extended medially and laterally to a point midway

2679

between the plantar and dorsal surfaces. The plantar incision is made along the digital crease and

extended diagonally medially and laterally to connect to the dorsal incision. The dorsal incision is

deepened to the periosteum, which is cleared with a small periosteal elevator. The metatarsal bones are

transected 0.5 to 1.0 cm proximal to the dorsal skin incision. The plantar flap is fashioned by continuing

the dissection just superficial to the metatarsal heads. Care is taken to maintain plantar flap thickness.

The nerves and tendons are transected sharply under tension and allowed to retract. The plantar flap is

rotated anteriorly and assessed for length. Excess tissue is excised sharply and the deep tissue is

approximated with absorbable suture. The skin is closed without tension using monofilament suture or

skin staples.

Weight bearing is delayed for 1 month to allow adherence of the plantar flap. Either a soft dressing or

a short leg cast can be used for a postoperative dressing.

Staging a tendo-achilles lengthening (TAL) is important to consider following (or at the same time if

no infection is present) a partial foot amputation. Ulcer formation at the TMA stump site is often related

to equinus formation due to the ensuing flexion/extension imbalance that occurs after resection of the

forefoot. A simple triple-hemisection percutaneous TAL can effectively lengthen the achilles and reduce

future pressures at the stump site.32 Other tendon-balancing procedures may be needed to control varus

and valgus contraction deformities that can develop.

Figure 94-2. A: Digital amputation. A circumferential skin incision is made proximal to the gangrenous process. The proximal

phalanx is transected and the soft tissue approximated. B: Metatarsal head resection (ray amputation). A racquet-shaped skin

incision is made with the circular component extending circumferentially around the digit and the longitudinal component

extending proximal to the metatarsal head. The metatarsal is transected proximal to the head and the soft tissue approximated.

Syme Amputation

The Syme amputation is a foot amputation that preserves limb length and the epiphyseal growth plates,

and allows occasional ambulation without a prosthesis. It is indicated in cases of extensive foot trauma

or other nonviable tissue conditions distal to the hindfoot. The Syme amputation is contraindicated if a

2680

supple intact heel pad and a well-vascularized hindfoot tissue flap are not available.

The procedure can be performed in one or two stages, as illustrated in Figure 94-4. The initial steps

for both procedures are identical, except that the skin incision for the two-stage procedure is located 1.5

cm more distally. The skin incision for the one-stage procedure extends from the medial to the lateral

malleolus in the horizontal and vertical planes. The dorsal incision is extended to the bone, and the

tendons are transected under tension. The anterior tibial artery is identified, divided, and suture ligated.

The dissection is carried into the tibiotalar joint space as the foot is forcibly plantar flexed. The

ligaments are transected and the talus is dislocated. The plantar aspect of the incision is deepened to the

calcaneus, and the calcaneus is sharply dissected from the plantar fascia. The plantar fascia is densely

adherent and care must be taken to prevent damage to the heel pad, especially at the level of the

Achilles tendon. The posterior tibial artery must be preserved, because it perfuses the heel pad. The foot

is then removed. The two procedures differ from this point forward.

In the one-stage procedure, the medial and lateral malleoli are transected flush with the tibiotalar

joint space, and the heel pad is rotated over the ends of the tibia and fibula. The deep fascial layers are

approximated with absorbable suture and the skin is closed with monofilament suture or skin staples.

Securing the distal end of the remaining plantar fascia to a small drill-hole in the distal anterior tibia

will help anchor the plantar flap and reduce posterior migration. In the two-stage procedure, the heel

pad is similarly positioned and the wound is closed without further bone transection. In 6 weeks,

elliptical incisions are made over the medial and lateral malleoli and the distal ends of the tibia and

fibula are transected flush with the ankle joint. In addition, the distal flares of the tibia and fibula are

transected, creating the rectangular stump of the two-stage procedure. The wound is closed in a similar

fashion. For both procedures, weight bearing is delayed for at least 4 weeks to allow heel pad fixation.

A soft dressing or a short leg cast can be used.

Below-Knee Amputation

The complications of diabetes and arterial insufficiency constitute most of the indications for BKAs.

Tables 94-5 and 94-6 outline the criteria used to decide between a BKA and an AKA in this setting.

Figure 94-3. A: The skin incision for the transmetatarsal amputation is made on the dorsum of the foot immediately proximal to

the metatarsal heads and on the plantar surface within the digital crease. B: The metatarsal heads are transected proximal to the

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