Ankle Arthrodesis Using Ring External Fixation - Orthofix.com

performed with Ilizarov external fixation for ankle
pathology associated with extensive periarticular bone
loss and severe deformity. All joints were fused in
anatomical alignment, and patients had greatly
improved their functional status. Sakurakichi et al 7
noted that complex ankle arthrodesis could be effectively
be performed with simultaneous proximal tibial
lengthening using the Ilizarov external fixator. Although
the series included only 6 patients, all patients healed
their arthrodesis sites and gained 2 to 3 mm with
simultaneous lengthening.
Probably the most compelling article is Katsenis
et al’s 8,9 report of 21 revision ankle arthrodeses
performed using the Ilizarov external fixator to manage
nonunions/malunions about the ankle. Despite the
patients having complex hindfoot pathology, all 21
healed and with a plantigrade foot. At an average
follow-up of 12 years, 18 of 21 had good to excellent
results. The authors pointed out that external fixation
requires considerable attention and reported 20 major
complications intraoperatively and 7 postoperatively.
We conducted a similar study at our institution (on
a program for American Orthopaedic Foot and Ankle
Society Summer Meeting, San Diego, CA, July 2006).
We analyzed 22 consecutive revision ankle arthrodesis
performed for nonunions using ring external fixation
(Figs. 25AYC). All patients had at least 1 prior attempt
at arthrodesis using internal fixation. The average
number of surgeries before revision arthrodesis was 2
(range, 1Y8). External fixation was maintained for an
average of 15 weeks (range, 12Y44 weeks). Union (time
to removal of external fixation) was suggested by
evidence of bridging trabeculation at the arthrodesis
site in 3 standard radiographic views of the ankle. In
cases where union could not be adequately determined
on radiographic views or the arthrodesis site was
obscured by the external fixator, a limited CT scan
was obtained to assess union. All 22 patients were
available for follow-up at an average of 51 months
(range, 15Y62 months). The average American Orthopaedic
Foot and Ankle Society ankle-hindfoot score
improved from 26 points (range, 0Y45 points) preoperatively
to 64 points (range, 0Y87 points) at final follow-up.
Tibiotalar fusion was achieved in 19 (86%) of 22
patients. In the 3 patients with persistent nonunions, one
had avascular necrosis of the talus and two had persistent
osteomyelitis. Two of these patients underwent rerevision
arthrodesis and one opted for amputation. Over the
course of treatment with external fixation, 34 minor
complications (pin tract infections [n = 24], broken pins
[n = 3], and cellulitis [n = 7]) were managed effectively
with local wound care, oral antibiotics, and/or pin
removal in the clinic setting. Four major complications
(deep infection [n = 2] and wound dehiscence [n = 2])
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Special Focus: Easley et al
were surgically addressed, while maintaining compression
at the arthrodesis site by external fixation. Three
patients had symptomatic malunions: varus (n = 2),
excessive valgus (n = 1), and equinus (n = 1). Hindfoot
motion was less than physiological in all patients
(compared with the contralateral extremity), despite
the external fixator being constructed to protect the
subtalar joint from concomitant compression.
Possible Concerns and Future
of This Technique
External fixation techniques are not practical for all
patients or surgeons. However, it is our opinion that
surgeons managing complex foot and ankle disorders
should have external fixation in their armamentarium
because there are situations when internal fixation
techniques are limited or contraindicated. Specifically,
revision arthrodesis and cases of septic arthritis/osteomyelitis
frequently lend themselves poorly to internal
fixation. With some focused training in learning
centers and residency training programs, most surgeons
can acquire skills to apply external fixation to ankle
arthrodesis. The future of this technique depends on
adequate teaching being made available and userfriendly
external fixation systems being developed. A
limiting factor remains that many surgeons without
formal external fixation training are intimidated by the
complexity of the traditional Ilizarov system (Figs.
26AYF). Newer systems have been introduced that tend
to be more forgiving, although they may forfeit some of
the versatility of the seemingly endless combinations of
external fixation constructs afforded by the original
systems. Although these newer systems may appear
simpler, surgeons must become familiar at least with the
fundamentals of the original Ilizarov method to consistently
and successfully use external fixation in
treating their patients with complex foot and ankle
disorders. We foresee that basic external fixation
techniques will become part of most residency training
programs, more courses will be offered through learning
centers as interest in external fixation grows, and
surgeons will become more facile with techniques of
external fixation. With emphasis on minimally invasive
approaches and the evolution of computer-assisted
surgery, external fixation will continue its development
as an integral part of precise surgical management of
complex disorders of the foot and ankle.
| REFERENCES
Techniques in Foot and Ankle Surgery
1. Monroe MT, Beals TC, Manol A 2nd. Clinical outcome of
arthrodesis of the ankle using rigid internal fixation with
cancellous screws. Foot Ankle Int. 1999;20:227Y231.
[526Y535].
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