Foot & Ankle International - September 2019 - 1041

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Yano et al

Figure 4. Kaplan-Meier survival curve for FINE total ankle
arthroplasties showing estimated survival of 88.4% (95% CI,
0.76-1.0) at 10 years, with removal of implant as the end point.
Each case was censored (as indicated by a vertical line) at the
time of the latest follow-up.

prosthesis designed to be mobile bearing.2 Preyssas et al
also described radiolucency in 125 of the 173 cases (72%)
after 3-component mobile-bearing TAA in a multisurgeon
and multicenter study.17 Nishikawa et al also found a high
radiolucency rate in patients with RA, similar to our
results.16 In addition, that study demonstrated angular
migration of the tibial component in 21.1% of ankles,
defined as a minimum change of 5 degrees in the component position. In contrast, Hirao et al described no cases of
tibial component migration after TAA using the FINE
Total Ankle System in RA patients.3 In that study, hydroxyapatite augmentation of the distal part of the tibia was performed,3,21 a procedure that may be important for avoiding
migration of the tibial component.
All radiolucencies in our study occurred within 2 years
after surgery. As this duration was relatively short, it may
indicate a problem with primary fixation or cementing techniques. Subsidence is a common problem after TAA and in
our study, talar component subsidence occurred in 11
(28.9%) of the 38 ankles. Hirao et al proposed that subsidence may be caused by a decrease in blood supply to the
talar dome after subtalar joint arthrodesis for RA patients.3
However, we found that 3 of 9 ankles that received subtalar
arthrodesis simultaneously developed subsidence, compared
to 8 of 30 ankles without arthrodesis, with this difference
between the groups being statistically insignificant (P =
1.0). Future studies may be necessary to assess the relationship between talar subsidence and subtalar joint arthrodesis.
Delayed wound healing was observed in 10 (25.6%)
ankles. Raikin et al reported that 27 (25.5%) of 106 ankles

had anterior incisions that required local wound care or oral
antibiotics without subsequent consequences, whereas 9
(8.5%) of 106 ankles required additional treatment in the
operating room. Multivariate logistic regression in their
study also demonstrated underlying inflammatory arthritis,
mostly RA, to be the only significant risk factor for major
wound complications, with an odds ratio of 14.03 for an
increased risk of requiring reoperation.19 In fact, in the present study delayed wound healing occurred in 10 (25.6%)
ankles, with one ankle developing a deep infection after
delayed wound healing. Because patients with RA have a
high risk of wound complications, all the patients in this
study used more conservative postoperative protocols than
the manufacturer recommended. However, although delaying the timing of initial ambulation and the removal of the
cast might have decreased wound complications, we still
had a high rate. A further troublesome problem in our study
was the relatively long mean duration of wound healing of
greater than 3 months (14.7 ± 16.7 weeks). Four ankle
prostheses were removed in this study. A Kaplan-Meier survival analysis showed a cumulative survival of 88.4% after
10 years, a rate consistent with a previous report on the
FINE Total Ankle System.3
The current study had some limitations. First, it was a
retrospective study of consecutive patients in a single
institution. Second, the cohort of patients was small,
which limits the generalizability of our results. One of the
reasons for the small sample size in this study was that
only 0.2 TAA per 100 000 inhabitants was performed
annually in Japan. This was very low compared with 1.9 to
4.0 per 100 000 inhabitants in the United States.10,18 Third,
preoperative clinical assessment of some patients was
insufficient, an unavoidable situation because the SAFE-Q
was only developed by the Japanese Society for Surgery
of the Foot in 2013. Finally, the follow-up period was not
very long. A longer follow-up period is therefore necessary to more comprehensively assess the outcomes of the
FINE Total Ankle System.
In conclusion, the midterm patient-reported outcomes
and implant survival rate after mobile-bearing TAA in RA
patients were satisfactory. However, a low radiographic
implant success rate was observed.
Declaration of Conflicting Interests
The author(s) declared the following potential conflicts of interest
with respect to the research, authorship, and/or publication of
this article: Koichiro Yano, MD, PhD, reports personal fees from
Teijin-Nakashima Medical, during the conduct of the study.
ICMJE forms for all authors are available online.

Funding
The author(s) received no financial support for the research,
authorship, and/or publication of this article.

Foot & Ankle International - September 2019

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