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Chapter 38: Prosthetic Management After Partial Foot Amputation
63. Geertzen JH, Jutte P, Rompen C,
Salvans M: Calcanectomy, an alternative amputation? Two case reports.
Prosthet Orthot Int 2009;33(1):78-81.
Medline DOI
64. Sobel E, Japour CJ, Giorgini RJ,
Levitz SJ, Richardson HL: Use of
prostheses and footwear in 110 inner-city partial-foot amputees. J Am
Podiatr Med Assoc 2001;91(1):34-49.
Medline DOI
65. Göktepe AS, Cakir B, Yilmaz B,
Yazicioglu K: Energy expenditure
of walking with prostheses: Comparison of three amputation levels.
Prosthet Orthot Int 2010;34(1):31-36.
Medline DOI
66. El-Hilaly R, Elshazly O, Amer A:
e role of a total contact insole in
diminishing foot pressures following
partial rst ray amputation in diabetic patients. Foot (Edinb) 2013;23(1):6-
10. Medline DOI
67. Czerniecki JM, Turner AP, Williams RM, Hakimi KN, Norvell
DC: Mobility changes in individuals with dysvascular amputation
from the presurgical period to 12
months postamputation. Arch Phys
Med Rehabil 2012;93(10):1766-1773.
Medline DOI
68. Norvell DC, Turner AP, Williams
RM, Hakimi KN, Czerniecki JM:
Dening successful mobility aer
lower extremity amputation for
complications of peripheral vascular
disease and diabetes. J Vasc Surg
2011;54(2):412-419. Medline DOI
69. Quigley M, Dillon MP: Quality of
life in persons with partial foot or
transtibial amputation: A systematic
review. Prosthet Orthot Int 2014;
September 2 [Epub ahead of print].
Medline DOI
70. Peters EJ, Childs MR, Wunderlich RP, Harkless LB, Armstrong
DG, Lavery LA: Functional status
of persons with diabetes-related
lower-extremity amputations. Di-
abetes Care 2001;24(10):1799-1804.
Medline DOI
71. Boutoille D, Féraille A, Maulaz D,
Krempf M: Quality of life with diabetes-associated foot complications:
Comparison between lower-limb amputation and chronic foot ulceration.
Foot Ankle Int 2008;29(11):1074-1078.
Medline DOI
72. Eckman MH, Greeneld S, Mackey
WC, et al: Foot infections in diabetic
patients: Decision and cost-eectiveness analyses. JAMA 1995;273(9):712-
720. Medline DOI
73. McCallum R, Tagoe M: Transmetatarsal amputation: A case series and
review of the literature. J Aging Res
2012; 797218. Medline
74. Arndt B, Caldwell R, Fatone S: Use of
a partial foot prosthesis with vacuum-assisted suspension: A case study.
J Prosthet Orthot 2011;23:82-88. DOI
75. Livingstone W, Mortel TF, Taylor
B: A path of perpetual resilience:
Exploring the experience of a diabetes-related amputation through
grounded theory. Contemp Nurse
2011;39(1):20-30. Medline DOI
76. Stone PA, Back MR, Armstrong PA,
et al: Midfoot amputations expand
limb salvage rates for diabetic
foot infections. Ann Vasc Surg
2005;19(6):805-811. Medline DOI
77. Apelqvist J, Armstrong DG, Lavery
LA, Boulton AJ: Resource utilization
and economic costs of care based on
a randomized trial of vacuum-assisted closure therapy in the treatment
of diabetic foot wounds. Am J Surg
2008;195(6):782-788. Medline DOI
78. Dillingham TR, Pezzin LE, MacKenzie EJ: Limb amputation and limb
deciency: Epidemiology and recent
trends in the United States. South
Med J 2002;95(8):875-883. Medline
79. Ragnarson Tennvall G, Apelqvist
J: Health-economic consequences
of diabetic foot lesions. Clin Infect
Dis 2004;39(suppl2):S132-S139.
Medline DOI
© 2016 American Academy of Orthopaedic Surgeons Atlas of Amputations and Limb Deciencies, Fourth Edition
471
Chapter 39
Ankle Disarticulation and Variants:
Surgical Management
Tobin T. Eckel, MD Benjamin B. Chi, MD Scott B. Shawen, MD
Abstract
Ankle disarticulation has declined in favor because of improvements in transtibial prostheses
and concerns about wound healing complications in more distal lower limb amputation.
However, ankle disarticulations and Pirogo and Boyd amputations remain practical
options for some patients. Careful screening and medical optimization of the patient
before surgery may reduce the rate of early complications. ese types of distal lower limb
amputations oer the advantages of end weight bearing and decreased metabolic demand
during ambulation.
Keywords: amputation; Boyd amputation; hindfoot; Pirogoff
amputation; Syme ankle disarticulation
Introduction
With recent advancements in transtibial prostheses and concern for wound
healing with more distal amputations,
ankle disarticulation has declined in
favor but still remains a viable option
in select patients. An ankle disarticulation is commonly referred to as a Syme
disarticulation because James Syme is
credited with first describing this procedure in 1843.
account for nearly 25% of all lower limb
amputations, whereas only 10% of all
lower limb amputations are performed
about the foot and ankle.
At the time Syme described his novel
ankle disarticulation, he noted less risk
to life, a more comfortable residual limb,
and a limb that would be more “seemly and useful for progressive motion”
as advantages of the procedure.4 These
claims remain largely unchallenged.
Dr. Shawen or an immediate family member serves as a board member, owner, ocer, or committee member of the American Orthopaedic Foot & Ankle Society and the American Orthopaedic
Foot & Ankle Society Humanitarian Aid Committee. Neither of the following authors nor any
immediate family member has received anything of value from or has stock or stock options held
in a commercial company or institution related directly or indirectly to the subject of this chapter:
Dr. Eckel and Dr. Chi.
1,2
Transtibial amputations
3
The mortality rate with ankle disarticulation has been reported as 33% at 5
years compared with 33% at 2 years
with transtibial amputation.5 Some
physicians have attributed the lower
mortality rate to decreased blood loss
and the ability to perform the procedure
under regional anesthesia rather than
the decreased severity of the peripheral,
and thus likely central, vascular disease
that may make the procedure an option
in patients with vasculopathy.6 The advantages of a lower mortality rate must
be tempered by the high failure rate of
ankle disarticulation, with revision rates
ranging from 20% to 50%.
7
The Syme ankle disarticulation
may offer the patient more comfortable
weight bearing because the heel pad is
preserved. The heel pad contains fat
cells enclosed by dense fibrous septa,
which allow direct weight bearing. The
preservation of the heel pad affords
end weight bearing without a prosthe-
1,3-5
sis.
Although the ability to bear direct
weight without a prosthesis is a substantial advantage, it is important to realize
that the weight is absorbed by a single
bony surface compared with an entire
foot consisting of joints and surrounding musculature that are specialized to
bear weight and adapt to uneven surfaces. For these reasons, weight bearing
without a prosthesis is typically limited
to very short distances.
2,8
However, the
ability for end weight bearing is very
important in prosthetic design. The
Syme disarticulation allows sockets to
function in suspension, whereas transtibial sockets bear weight by indirect
load transfer and require revision to prevent skin breakdown if volume changes
occur in the residual limb.2 Syme sockets also typically do not involve the knee
and are less prone to popliteal impingement with knee flexion.
Syme’s claim that the disarticulation
resulted in a more cosmetically pleasing limb would be disputed by many
physicians and patients because the
residual limb tends to be bulbous, and
early prostheses were considered unsightly.9 The malleoli are trimmed to
help decrease the size of the residuum,
both for cosmetic reasons as well as to
facilitate prosthetic fitting.8 Nonetheless, this amputation is more useful for
locomotion because of the increased
mechanical efficiency, which leads to
a decreased metabolic ambulatory cost.
The mechanical benefit is a result of a
full-length prosthetic foot that provides
a normal lever arm for push-off. The use
© 2016 American Academy of Orthopaedic Surgeons Atlas of Amputations and Limb Deciencies, Fourth Edition
473
Section 3: Lower Limb
Figure 1
the midfoot was severely compromised and ultimately nonviable, precluding salvage. Large soft-tissue and skin defects over the mid and proximal
tibia prevented a primary transtibial amputation. To preserve optimal length of the residual limb and provide stable soft-tissue coverage, a Syme disarticulation was planned. A, The distal sh-mouth incision with removal of the talus and calcaneus has been performed at this stage. Preoperative
radiographic views of the tibia (B) and the forefoot (C) show segmental comminution and multiple fractures and dislocations.
of a prosthetic foot with energy storage
and return can further improve gait
and walking speed while decreasing
metabolic demand.
energy expenditure for ambulation is
particularly advantageous in individuals with diabetes because they generally
have poorer baseline health and would
be less likely to ambulate with a transtibial prosthesis.
Indications
The indications for ankle disarticulation
are trauma, nonhealing diabetic and/
or dysvascular ulcers, Charcot arthropathy, crush injury, frostbite, congenital
malformations, and diabetic infection
(the most common indication). Approximately 7% of the US population
has diabetes, and this population has a
tenfold increased incidence of amputation. Individuals with diabetes account
for more than two-thirds of all lower
limb amputations. Because a preserved
heel pad with adequate blood flow is
a prerequisite for ankle disarticulation
regardless of the etiology, the only absolute contraindication to this procedure
is a compromised heel pad, which may
be the result of inadequate blood flow,
infection, or soft-tissue loss.
A, Intraoperative photograph of the lower limb of a patient who sustained severe injury from an e xplosion. The soft tissue surrounding
2,10
The decrease in
3
Candidates for ankle disarticulation
often have decreased perfusion. A major
challenge is determining which patients
have enough arterial flow to allow healing of an amputation at such a distal
level. Because many of these patients
lack a palpable posterior tibial pulse, the
ankle-brachial index can be measured.
Typically, an ankle-brachial index of
0.5 or higher indicates adequate blood
flow; however, patients with diabetes
often have calcified arteries that may
falsely elevate this measure.
1,3
Systolic
toe pressures are less affected by arterial
calcification and are an alternative noninvasive measurement to assess perfusion and wound healing capability, with
values less than 30 mm Hg indicative
of critical ischemia.11 Another perhaps
more accurate measurement of perfusion is the transcutaneous partial pressure of oxygen, with values between 20
and 30 mm Hg indicative of adequate
perfusion necessary for tissue healing.
Other laboratory tests that have been
used to help predict tissue healing capacity include a serum albumin level of
at least 2.5 g/dL and a total lymphocyte
count of greater than 1,500 mm3. Although healing rates as low as 50% have
1,5
been reported, studies have shown that
when all the aforementioned criteria
are met, healing rates can be as high as
12,13
88%.
If concerns about blood flow
persist, consultation with a vascular
surgeon is warranted, with options to
include angioplasty or even arterial bypass surgery to increase perfusion and
facilitate limb salvage at the more distal
amputation level (Figure 1).
Surgical Technique
For ankle disarticulation surgery, the
patient is placed supine with a thigh
tourniquet. An anterior fish-mouth incision is made with the apices located
at the anterior midpoints of the malleoli
and the distal plantar apex reaching a
few centimeters anterior to the tibia. The
incision is carried sharply to bone, although the peroneal and any saphenous
nerve branches should be cut under
tension to allow retraction and prevent
symptomatic neuroma formation at
1,3
the level of the incision. Subperiosteal dissection and removal of the talus
and calcaneus are then performed, with
care not to violate the posterior skin,
the heel pad, or damage the posterior
tibial vasculature, which is essential for
heel pad perfusion. Dissection can be
facilitated with the use of a large bone
Atlas of Amputations and Limb Deciencies, Fourth Edition © 2016 American Academy of Orthopaedic Surgeons
474
Chapter 39: Ankle Disarticulation and Variants: Surgical Management
hook on the talus and (subsequently) on
the calcaneus to forcefully plantarflex
the foot and stretch the soft tissues.
2,5,12
A traction bow also can be used with a
pin through the talus. This method offers an advantage over the use of a bone
hook because it does not require manual traction and may improve surgical
visualization.
14
The malleolar flares are then removed at the level of the tibial articular
surface and are beveled and smoothed
medially and laterally. This narrows the
residual limb, making it less bulbous
and more cosmetically pleasing, and it
also provides a broad surface of metaphyseal bone for soft-tissue adherence,
which helps in securing the flap.8 The
heel pad is then secured to the anterior
Figure 2
performed sharply under a tourniquet. A, Incision of skin and fascia is carried straight through to
the capsule. Major vessels are ligated with suture ties. B, Traction neurectomy of major identied
nerves is performed while the talus is disarticulated and calcaneus removed. C, The nal disarticulated foot. D, Soft-tissue coverage is planned with the talus and calcaneus removed. Tibial articular
cartilage can be seen at the distal end. The lateral malleolus is seen here but will be resected to
provide an even surface for weight bearing. E, The proposed position of closure allows a viable fat
pad of the heel to provide a cushioned surface. F, The skin is closed and suction drains are placed.
G, The lower leg after skin closure demonstrating a large lateral soft-tissue wound.
tibia through drill holes to help prevent heel pad migration. Securing the
Achilles tendon to the posterior tibia
with tenodesis through drill holes to
help secure the heel pad in place and
negate the posterior and proximal pull
of the triceps surae is also advocated.15
Additional techniques to prevent heel
pad migration, particularly varus migration, include tenodesis of the peroneal
tendons to the lateral heel pad or securing the lateral band of the plantar fascia
to the lateral aspect of the tibia.
Suction drains are optional before closure and the application of gentle com-
Intraoperative photographs of ankle disarticulation surgery. Disarticulation can be
the patient can be fitted with an initial
prosthesis.
2,12
As a method to assess flap
viability and minimize infection, Wagner17 described a two-stage technique
in which the malleolus was resected in
the first stage, and skin closure was performed in a second surgical procedure.
However, this technique has largely
been replaced with a single-stage procedure in which bony resection and skin
closure are performed in one setting.
Healing rates are similar between the
2,6,12,16
one- and two-stage procedures, and the
morbidity associated with a second procedure is avoided.
18
pressive dressings and a cast. Interval
casting is continued until the wound
is healed and the residual limb volume
has stabilized (Figure 2). At this point,
Outcomes
Historically, outcomes after ankle disarticulation were poor, particularly in
© 2016 American Academy of Orthopaedic Surgeons Atlas of Amputations and Limb Deciencies, Fourth Edition
475
Section 3: Lower Limb
Figure 3
articulation. B, Follow-up radiograph taken 3 months after surgery shows healing of the residual
limb. Additional procedures during the Syme ankle disarticulation included bulectomy, proximal
tibiobular xation, and retrograde intr amedullary nailing. The patient progre ssed to weight bearing with a prosthetic shoe.
patients with diabetes. Failure often required revision within the first year in
20% to 50% of patients.7 More recent
data indicate more promising outcomes.
A retrospective review by Pinzur et al12
reported a 90% success rate after Syme
ankle disarticulation in patients with
diabetes. These improved outcomes are
A, Immediate postop erative AP radiograph of the lower limb after a Syme ankle dis-
a transfemoral amputation.
3,13
A Syme
ankle disarticulation also permits end
weight bearing without a prosthesis.
Although this allows ambulation for
short distances only, as many as 70%
of patients with a Syme disarticulation
are able to use end weight bearing at
home7 (Figure 3).
likely the result of careful patient selection, ensuring adequate arterial blood
flow, and imposing sufficient nutrition
parameters before surgery.
The most common early complication
is delayed wound healing or infection,
which occurs in approximately 25% of
patients, but can usually be managed
with local wound care. Heel pad migration is the most common late complication, occurring in approximately 30%
of patients. Rates of heel pad migration
may be reduced by using the previously
described techniques.
2,12
Ankle disarticulation affords several
advantages over amputation at higher
levels, including earlier weight bearing;
minimal prosthetic gait training; improved gait velocity, cadence, and stride
length; and less energy expenditure
and cardiovascular demand with ambulation. These patients also have a decreased 5-year mortality rate compared
with those treated with a transtibial or
Alternative Hindfoot
Amputations
The previously described methods of
ankle disarticulation refer to a softtissue procedure. In procedures such as
Boyd or Pirogoff amputations, calcaneal
bone stock is retained and fused to the
distal tibial. These procedures provide
several advantages over ankle disarticulation without osteoplasty. Preservation
of calcaneal bone retains greater limb
length and prevents subluxation of the
heel pad if osseous union is obtained.19
In low-demand patients, maintenance of
limb length and heel pad preservation
allows for the use of very rudimentary
prostheses. A limitation of these methods is that the already limited space for
advanced prosthetic ankle components
or running legs is substantially reduced.
The technique used in the osteoplasty modification is only slightly different from the traditional Syme ankle
disarticulation. In the Boyd amputation, the talus and anterior calcaneus
are removed, as well as the calcaneal
surface of the subtalar joint. Tibiofibular and tibiocalcaneal fusion is then
performed.20 In the Pirogoff amputation,
the anterior two-thirds of the calcaneus is excised and the residual calcaneal
fragment, with the Achilles tendon attached, is rotated and fixed distally to
the tibia. Calcaneal rotation allows the
preservation of limb length.
19,21
Fixation
of the bone and heel pad fragment has
been described using several modalities,
including Ilizarov-type frames and internal fixation with compression screws
placed in a crossed configuration.
22
Indications for use of a Boyd or Pirogoff amputation are the same as for the
Syme ankle disarticulation; however,
they require healthy osseous and soft
tissue at the calcaneus. Clinical results
are dependent on union of the calcaneal and tibial fragments. Outcomes after
a Boyd or a Pirogoff amputation have
poorer rates of union and healing in pa
tients with vascular disease and diabetes
than those performed in patients with a
traumatic injury. A thorough assessment
of the overall clinical status of a patient
being considered for a Pirogoff or Boyd
amputation is recommended.
19
Postoperative care is the same as that
given for patients treated with a Syme
ankle disarticulation, but the patient can
be fitted with an “elephant boot” to allow
distal weight bearing with minimal loss
of limb length. In areas where more sophisticated ankle-foot prostheses are not
available, Pirogoff and Boyd amputation
techniques provide a viable alternative
treatment.
Summary
Ankle disarticulation and Pirogoff and
Boyd amputations remain viable options
for lower limb amputation. Early complications can be mitigated with careful
screening and medical optimization of
the patient before surgery. The advantages of end weight bearing and the
-
Atlas of Amputations and Limb Deciencies, Fourth Edition © 2016 American Academy of Orthopaedic Surgeons
476
Chapter 39: Ankle Disarticulation and Variants: Surgical Management
decreased metabolic demand of ambulation cannot be overstated in a patient
population that often has many medical comorbidities and little functional
reserve.
References
1. Philbin TM, Berlet GC, Lee TH:
Lower-extremity amputations in
association with diabetes mellitus.
Foot Ankle Clin 2006;11(4):791-804.
Medline DOI
2. Pinzur MS: Syme’s ankle disarticulation. Foot Ankle Clin
2010;15(3):487-494. Medline DOI
3. Smith DG: Amputation: Preoperative assessment and lower extremity
surgical techniques. Foot Ankle Clin
2001;6(2):271-296. Medline DOI
4. Harris RI: Syme’s amputation: e
technical details essential for success.
J Bone Joint Surg Br 1956; 38(3):614-
632. Medline
5. Philbin TM, Deluccia DM, Nitsch RF,
Maurus PB: Syme amputation and
prosthetic tting challenges. Tech
Foot Ankle Surg 2007;6(3):147-155.
DOI
6. Bibbo C: Modication of the Syme
amputation to prevent postoperative
heel pad migration. J Foot Ankle Surg
2013;52(6):766-770. Medline DOI
7. Gaine WJ, McCreath SW: Syme’s
amputation revisited: A review
of 46 cases. J Bone Joint Surg Br
1996;78(3):461-467. Medline
8. Fergason J, Keeling JJ, Bluman EM:
Recent advances in lower extremity amputations and prosthetics
for the combat injured patient.
Foot Ankle Clin 2010;15(1):151-174.
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9. Diveley RL, Kiene RH: An improved
prosthesis for a syme amputation:
Rex L. Diveley MD (1893-1980),
Richard H. Kiene MD. Clin Or-
thop Relat Res 2008;466(1):127-129.
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10. Mulder IA, Holtslag HR, Beersma LF,
Koopman BF: Keep moving forward:
A new energy returning prosthetic
device with low installation height
aer Syme or Pirogo amputation.
Prosthet Orthot Int 2014;38(1):12-20.
Medline DOI
11. Romanos MT, Raspovic A, Perrin
BM: e reliability of toe systolic
pressure and the toe brachial index in
patients with diabetes. J Foot Ankle
Res 2010;3:31. Medline DOI
12. Pinzur MS, Stuck RM, Sage R, Hunt
N, Rabinovich Z: Syme ankle disarticulation in patients with diabetes.
J Bone Joint Surg Am 2003;85(9):1667-
1672. Medline
13. Frykberg RG, Abraham S, Tierney E,
Hall J: Syme amputation for limb salvage: Early experience with 26 cases.
J Foot Ankle Surg 2007;46(2):93-100.
Medline DOI
14. Oznur A: Syme ankle disarticulation:
A simplied technique. Foot Ankle
Int 2001;22(6):484-485. Medline
15. Smith DG, Sangeorzan BJ, Hansen
ST Jr, Burgess EM: Achilles tendon tenodesis to prevent heel pad
migration in the Syme’s amputation.
Foot Ankle Int 1994;15(1):14 -17.
Medline DOI
16. Smith NC, Stuck R, Carlson RM,
Dux K, Sage R, Pinzur M: Correction of varus heel pad in patients
with Syme’s amputations. J Foot
Ankle Surg 2012;51(3):394-397.
Medline DOI
17. Wagner FW Jr: Amputations of the
foot and ankle. Current status. Clin
Orthop Relat Res 1977;122:62-69.
Medline
18. Pinzur MS, Smith D, Osterman H:
Syme ankle disarticulation in peripheral vascular disease and diabetic
foot infection: e one-stage versus
two-stage procedure. Foot Ankle Int
1995;16(3):124-127. Medline DOI
19. Taniguchi A, Tanaka Y, Kadono K,
Inada Y, Takakura Y: Pirogo ankle
disarticulation as an option for ankle
disarticulation. Clin Orthop Relat Res
2003;414:322-328. Medline DOI
20. Tosun B, Buluc L, Gok U, Unal C:
Boyd amputation in adults. Foot
Ankle Int 2011;32(11):1063-1068.
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21. Langeveld AR, Meuels DE, Oostenbroek RJ, Hoedt MT: e Pirogo amputation for necrosis of the
forefoot: Surgical technique. J Bone
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22. Gessmann J, Citak M, Fehmer T,
Schildhauer TA, Seybold D: Ilizarov
external frame technique for Pirogo
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© 2016 American Academy of Orthopaedic Surgeons Atlas of Amputations and Limb Deciencies, Fourth Edition
477
Chapter 40
Syme Ankle Disarticulation: Prosthetic Management
JoAnne L. Kanas, PT, CPO, DPT Phillip M. Stevens, MEd, CPO, FAAOP
Abstract
A Syme ankle disarticulation is arguably the most functional amputation level in the lower
limb. e procedure typically allows for an optimal gait pattern because of the preservation
of a long residual limb and good muscle strength in the hip and knee proximal to the amputation. However, prosthetic ttings can be challenging because of the long and bulbous
shape of the residual limb, which can result in less than optimal cosmesis and limitations
on options for prosthetic componentry and feet.
Keywords: lower limb prosthesis; prosthetic design; Syme ankle
disarticulation; through-ankle disarticulation
Introduction
An amputation through the ankle joint
was originally described by Syme1 in
1843. Although his initial surgical
technique has undergone changes and
refinements over time, it remains an ankle disarticulation in which the distal
prosthetic foot options. This chapter reviews the anticipated outcomes associated with a Syme ankle disarticulation
along with its inherent advantages and
disadvantages. Variations in socket and
suspension designs as well as compo-
nent considerations are discussed.
heel tissue is reattached to the limb to
allow direct weight bearing through its
distal end (Figure 1). Although an ankle disarticulation is arguably the most
functional amputation level;2 only 5% of
patients treated by certified prosthetists
in the United States have undergone a
Syme ankle disarticulation.3 These di
vergent observations are the result of
the striking advantages and disadvantages associated with this amputation
level. The inherent advantages include
full distal weight bearing, a long lever
arm, anatomic suspension, and minimal
disturbance to growth plates. The disadvantages are the difficulty in creating
a cosmetically acceptable prosthesis and
the reduced space available for modern
Mr. Stevens or an immediate family member is an employee of Hanger Clinic and serves as a
board member, owner, ocer, or committee member of the American Academy of Orthotists and
Prosthetists. Neither Ms. Kanas nor any immediate family member has received anything of value
from or has stock or stock options held in a commercial company or institution related directly or
indirectly to the subject of this chapter.
Anticipated Outcomes
Ankle disarticulation is indicated for
several different adult patient popula-
tions: those with vascular compromise,
diabetes mellitus with gangrenous tis-
sue, severe Charcot foot arthropathy,
-
nonhealing dysvascular ulcers, severe
diabetic ulcers, trauma, crush injuries,
severe frostbite, and malignancy.
expected outcomes associated with this
disarticulation level vary with the un-
derlying etiology and overall health and
well-being of the patient.
Siev-Ner et al5 reported on the results
of ankle disarticulations in 70 patients.
The procedure was performed in 51 of
the patients because of diabetic vascular
4,5
The
Figure 1
patient after a right ankle disarticulation.
Photograph of the limb of a
disease. A successful outcome was defined as one in which revision amputation was not needed in the first year
postoperatively and the patient received
a prosthesis and completed prosthetic
gait training. Using these criteria, success rates of 94% were reported for the
© 2016 American Academy of Orthopaedic Surgeons Atlas of Amputations and Limb Deciencies, Fourth Edition
479
Section 3: Lower Limb
19 patients without vascular disease
and 49% for those with vascular disease. Further classification based on age
in those with vascular disease showed
the success rate was 68% for patients
younger than 65 years, 31% for those
65 to 69 years, and 14% for those older
than 70 years.
Yu et al4 reported on a cohort of
mixed etiology, including Charcot
arthropathy, osteomyelitis, crush injury, and elective amputation of severe
clubfoot. Nine of 10 patients achieved
ambulation with a prosthesis by 4 to
6 months after a Syme ankle disarticulation, and 7 patients reported improved
quality of life and return to activities of
daily living.
In a retrospective study of patients
treated with a Syme ankle disarticulation, Pinzur et al6 evaluated 97 patients
with diabetes mellitus with a mean age
of 53 years and at least 2 years of follow-up. Of 82 patients whose wounds
healed, 80 were able to use a prosthesis, a higher rate than that generally
observed among patients with diabetes
who have more proximal amputations.
Of these, 50% were classified as household walkers and 50% as community
walkers.
Frykberg et al7 reported on a cohort
of 26 patients who underwent a Syme
ankle disarticulation. Prior to surgery,
these patients had an infection and/or
substantial peripheral arterial disease
and 92% had diabetes. Even with prior
recommendation for transtibial or transfemoral amputation in all patients and
a high rate of postoperative complications, including dehiscence, recurrent
osteomyelitis, infection, and pressure
ulcers, 65% of the patients successfully
attained initial ambulation with a prosthesis. However, several of the patients
required more proximal amputations at
a mean of 28 weeks after the ankle disarticulation because of progressive sepsis or recurrent ulcers. Ultimately, 46%
of the patients were functioning well
with an ankle disarticulation prosthesis
approximately 1 year postoperatively.
The preoperative patient criteria were
less strict than in other published standards and may have resulted in the comparatively high failure rate, but several
patients who would have been excluded
using stricter criteria went on to ambulate successfully with a prosthesis
after ankle disarticulation. Thus, the
success of prosthetic ambulation after
ankle disarticulation varies, depending on the causative etiology and other
medical considerations. Traumatic amputees appear to do quite well, whereas
the success of amputees with vascular
comorbidities is more varied.
Clinical Considerations
A few unique clinical considerations differentiate ankle disarticulation from the
more common transtibial amputation.
These include the defined benefits and
drawbacks of the associated shape and
length of the residual limb, the preservation of the distal heel pad with the
associated ability to bear weight distally,
and the cosmetic challenges associated
with the disarticulation prosthesis.
Residual Limb Shape and Length
After ankle disarticulation, the residual
limb is characterized by an often pronounced bulbous contour secondary to
the shape of the distal tibia and fibula.
In addition, the heel pad is spared from
the ablated foot during surgery and reattached distal to the tibia and fibula.
Proponents of ankle disarticulation cite
several associated benefits to this characteristic limb shape and length. Because
of the absence of any transected long
bones, coupled with the preservation
of the heel pad of the foot, the residual
limb often has the potential to provide
distal end bearing with increased proprioception following ankle disarticulation. In addition, by preserving the
entire length of the tibia and fibula, one
of the most important and unique advantages of ankle disarticulation is that
it permits limited ambulation without
a prosthesis, albeit with a considerable
limb-length discrepancy. Although this
limb-length discrepancy and the stability of the distal heel pad preclude ambulation over extended distances, limited
direct end bearing can be useful for
short-distance ambulation in the home
(for example, for a nightly bathroom visit) or at a swimming pool. In addition,
the extended length of the residual limb
after ankle disarticulation provides a
long lever arm for control of a prosthesis.
When the position or stability of the distal heel pad is compromised and distal
weight bearing is poorly tolerated, the
extended length of the residual limb also
provides a large surface area over which
proximal weight-bearing forces can be
distributed. The bulbous shape of the
ankle disarticulation also provides the
ability to self-suspend the prosthesis.
These benefits notwithstanding, several clear disadvantages are associated
with the prosthetic management of a
patient after an ankle disarticulation.
The extended length of the residual
limb can limit prosthetic component
options. In an adult treated with ankle
disarticulation, the available space is
inadequate to fit a higher profile prosthetic foot capable of energy storage and
return and shock absorption. Similarly,
space is limited for modular components
that can be used in more proximal limb
prostheses for alignment adjustability.
Providing a cosmetically acceptable
ankle disarticulation prosthesis can be
challenging, especially for an individual
with a more bulbous residual limb.
Heel Pad
The heel pad is optimally positioned in
line with the long bones of the lower
leg to provide a physiologic cushion
at the distal end of the residual limb.
Depending on the surgical procedure
used, the heel pad can become unstable,
migrating from the preferred position.
If a displaced heel pad remains mobile,
a well-fitted prosthesis can maintain its
position at the distal aspect of the limb.
Atlas of Amputations and Limb Deciencies, Fourth Edition © 2016 American Academy of Orthopaedic Surgeons
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