Foot & Ankle International - July 2018 - 826

826

Foot & Ankle International 39(7)

Table 4. Odds of ESRD Patients Receiving Operative Treatment
for Achilles Tendon Ruptures Within 14 Days of Injury, US Renal
Data System and Centers for Medicare & Medicaid Services, 19992013.
Parameters
ESRD treatment
Transplanted
Nonwaitlisted
Waitlisted
Age group, y
0-49
50-64
65-69
70-100
Race
White
Black
Other
Sex
Female
Male
Body mass index, kg/m2
0-24.99
25.00-29.99
30.00-39.99
≥40
Cause of ESRD
Glomerulonephritis
Diabetes mellitus
Hypertension
Other/missing

Adjusted OR (95% CI)

P Value

Referent
1.52 (0.97-2.39)
1.35 (0.83-2.20)

.1
.2

1.53 (0.92-2.54)
1.08 (0.66-1.76)
Referent
0.64 (0.37-1.11)
Referent
1.04 (0.71-1.52)
0.36 (0.11-1.22)

.1
.8
.1

.9
.1

Referent
0.86 (0.62-1.20)

Referent
1.11 (0.70-1.75)
0.79 (0.49-1.26)
0.75 (0.38-1.50)

.7
.3
.4

Referent
0.65 (0.37-1.13)
0.55 (0.29-1.03)
0.98 (0.53-1.80)

.1
.1
.9

Abbreviations: CI, confidence interval; ESRD, end-stage renal disease; OR,
odds ratio.

patients (6.07 per 10 000 person-years) and transplant recipients (5.22 per 10 000 person-years) compared with nonwaitlisted patients (2.91 per 10 000 person-years). These differences
persisted after adjustment for potential confounders.
There were no significant differences in ATR rates
between waitlisted patients and transplant recipients. This
suggests that the steroids and immunosuppressive medications taken by patients after transplant do not substantially
increase the risk of ATR. A second possibility is that the
transplant medications and metabolic abnormalities of dialysis are equally deleterious to the Achilles tendon, leading
to similar rupture rates in similarly active patients.
The risk factors for ATR identified in our study differ
from those in the general population. The risk of ATR was
higher in women than men. This is in contrast to studies of
the general population, which reported a higher risk in
men12,16,19,20,22,24,28,33 or no difference between the sexes.8
ATR incidence was also higher in white patients than black
patients. Studies of military personnel have shown a greater

Figure 1. Proportion of 1091 patients with end-stage renal
disease treated operatively for Achilles tendon rupture, 19992013. Bars indicate 95% confidence intervals.

risk of ATR in black patients than in those of other races.6,34
This discordance may suggest that the cause of ATR in
patients with ESRD is different from the cause in the general population. ATR typically occurs in "weekend warriors" playing recreational sports. We speculate that ATR in
the ESRD population is less attributable to sports and more
attributable to other factors such as metabolic abnormality,21,27 use of fluoroquinolones and steroids,5,30 lower levels
of regular physical activity,2 or preinjury tendinosis.14,35
Although there is evidence supporting both operative
and nonoperative treatment, less than 20% of the patients in
our study were treated operatively. In another study of
Medicare patients with ATR, nearly 30% of patients older
than 65 years were treated operatively.8 Our findings suggest that surgeons may favor nonoperative treatment for
patients with ESRD. However, whether ESRD is a true contraindication for surgery is unknown.
We hypothesized that waitlisted patients would be less
likely to receive surgery because surgery could harm their
chances for a transplant. For example, patients who undergo
surgery and develop SSI may be prevented from receiving a
transplant because of active infection.26 Our results do not
support this hypothesis. The rates of surgery for the waitlisted and transplanted groups were similar.
The rates of surgery did not change significantly during the
study period. This is in contrast to our hypothesis that operative
rates would decrease in response to studies showing equivalence between nonoperative and operative treatment. Such a
decrease has been documented in the general population.23 It is
difficult to determine why operative rates did not decrease over
time for patients with ESRD. It is possible that the rates were
already so low that the new evidence of the equivalence of
nonoperative treatment had little effect.
Other studies have found an association of ATR with
fluoroquinolone use and corticosteroid use.5,30 The use of

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