Foot & Ankle International - July 2018 - 792

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Foot & Ankle International 39(7)

Figure 7. Weightbearing, lateral radiograph of the ankle
showing a 2.1-mm periprosthetic radiolucent line through
the entire extension of the tibial implant-bone interface. The
patient was asymptomatic at the last follow-up visit, and the
radiolucency did not progress in comparison to previous
radiographs.

(3.1%) around the talar component. In both cases, the radiolucencies were smaller than 0.5 mm and the patients were
asymptomatic.
One case (1.5%) of cyst formation was noted. The patient
developed a 9-mm cyst in the medial aspect of the distal
tibia (Figure 8), which was noted at the 18-month follow-up
visit. The patient was asymptomatic and the lesion was still
being monitored.

Clinical outcomes
One-year postoperative patient-reported outcome scores as
measured with the Foot and Ankle Outcome Score (FAOS)21
demonstrated significant improvement for all the components analyzed (pain, symptoms, activities of daily living,
and quality of life) when compared to the preoperative time
point (Table 3).

Discussion
The main objective of the present study was to evaluate the
early complications, reoperations and survivorship of the
Infinity TAA. To our knowledge, this is the first report to
provide the early clinical results of this implant.
Complications were noted in 21.8% of the ankles, though
most did not require revision nor were they deemed failures. The most common complication was gutter impingement, which represented 29% of the complications observed

Figure 8. Weightbearing, anteroposterior radiograph of the
ankle showing cystic formation in the medial aspect of the distal
tibia. The patient was asymptomatic at the last follow-up visit
and is currently being monitored.

in this study. Several studies10,12,24,33 do not include gutter
impingement as a complication in their results, which can
dramatically reduce the reported rates of adverse outcomes.
Early complication rates following TAA range from 22% to
54% when gutter impingement is included,14,18,22,27 in accordance to our results. Asymptomatic periprosthetic cyst was
also included as a complication, because this condition
often leads to the need for reoperation.3,25 In agreement with
our results, gutter impingement is reported to be the most
common cause of reoperations in TAA.20,24,27,29 Therefore,
we believe that the cases observed in this study were due to
the inherent risk of impingement after TAA, and not caused
by the specific implant or operative technique issues.
In the present study, 12 reoperation procedures were necessary in 11 ankles (17.1%), in accordance with the rates
reported in previous short-term follow-up studies,4,14,24,31
that range from 7.7% to 24%. Tan et al31 reported a reoperation rate of 20% at an average follow-up of 18 months with
the use of a novel fixed-bearing TAA. Even though the relatively high rate of reoperations after TAA remains a concern,15 in most cases the required procedures are relatively
simple and caused by minor complications that do not put
the implant at risk of failure.

Table of Contents for the Digital Edition of Foot & Ankle International - July 2018