Foot & Ankle International - June 2017 - 629

Cho et al
and Ankle Outcome Score (FAOS), and Foot and Ankle
Ability Measure (FAAM) scores. These scores were measured prior to surgery, at 1 year postoperatively, and at final
follow-up. The AOFAS ankle-hindfoot rating score is a 100point physician-based scale comprised 3 subcomponents:
pain (40 points), alignment (15 points), and function (45
points). FAOS14 is a self-estimated test that consists of 42
questions and 5 subscales evaluating pain, other symptoms,
activities of daily living, sports activities, quality of life.
FAAM7 is composed of 2 subscales evaluating activities of
daily living (21 questions) and sports activities (8 questions).
Results were represented as scores changed on the basis of
100 points.
Both active and passive range of motion (ROM) of the
ankle joint with the knee extended were measured using a
goniometer prior to surgery, at 1 year postoperatively, and
at final follow-up. Gait was assessed by observation of the
patient while walking. In addition, patient's subjective satisfaction scores regarding operation, complications, and
reoperation rates were documented at final follow-up.
The grade of manual muscle power (ankle dorsiflexors,
plantarflexors, invertors and evertors) were evaluated on a
scale of 0 to 5 prior to surgery, at 1 year postoperatively and
final follow-up. To assess the changes of muscle strength
more objectively, examinations using Biodex-II isokinetic
testing machine (Biodex Medical Systems, Shirley, NY)
were performed prior to surgery and at final follow-up.
Peak torque of ankle dorsiflexors, plantarflexors, invertors,
and evertors were measured at 60 degrees/sec and 90
degrees/sec angular velocities. Deficit ratio of muscle
strength relative to the contralateral side was analyzed. All
measurements were compared to the data from the sex- and
age-matched controls.
Radiographic evaluation for the changes of postoperative foot alignment included Meary angle (talo-first metatarsal angle), calcaneal pitch angle, hindfoot alignment
angle, and navicular height (distance of the most plantar
aspect of the navicular to a line joining the plantar fifth
metatarsal head to the plantar calcaneus) measured prior to
surgery, at 1 year postoperatively, and at final follow-up. All
measurements were independently performed by 2 orthopedic surgeons. Measures were repeated twice, and subsequently averaged.
Statistical analysis was performed using SPSS (version 20.0; SPSS Inc, Chicago, IL, USA), and P values
less than .05 were considered statistically significant. All
data showed a normal distribution in the KolmogorovSmirnov test. Differences between preoperative and postoperative functional and radiologic outcome variables in
each individual were analyzed using Wilcoxon signedrank test. Functional outcomes at final follow-up were
also compared to the matched control group using MannWhitney test.

629

Results
Mean AOFAS scores significantly improved from 65.1 points
(range, 52-77 points) preoperatively to 86.2 points (range,
76-98 points) at final follow-up (P < .001). There was a statistically significant difference in the function subscale between
preoperative and postoperative AOFAS scores (Table 1). The
mean FAOS significantly improved from 55.6 points (range,
41-72 points) preoperatively to 87.8 points (range, 78-96
points) at final follow-up (P < .001). There were statistically
significant differences between preoperative and postoperative scores in all FAOS subscales except for the pain subscale.
Mean FAAM scores significantly improved from 45.7 points
(range, 30-65 points) preoperatively to 84.4 points (range,
75-96 points) at final follow-up (P < .001). There were statistically significant differences in both daily living and sports
activities between preoperative and postoperative FAAM
scores. The mean patient satisfaction score was 94.5 points
(range, 80-100 points) at final follow-up visit.
Mean active dorsiflexion of the ankle joint significantly
improved from -32.5 degrees (range, -40 to -20 degrees)
preoperatively to 11.8 degrees (range, -5 to 20 degrees) at
final follow-up (P < .001), and mean active plantarflexion
was 33.5 degrees (range, 25-40 degrees) at final follow-up.
Mean passive dorsiflexion significantly improved from 6.8
degrees (range, -10 to 20 degrees) preoperatively to 17.5
degrees (range, 10-20 degrees) at final follow-up (P < .001),
and mean passive plantarflexion was 35.2 degrees (range,
30-40 degrees) at final follow-up (Table 2). There were no
statistically significant differences in plantarflexion, inversion, or eversion between preoperative and postoperative
ROM.
Mean grade of muscle power of ankle dorsiflexors significantly improved from 1.1 preoperatively to 3.9 at final
follow-up (P < .001). In contrast, the muscle power of
plantarflexors was slightly reduced from grade 4.8 preoperatively to grade 4.4 at final follow-up (P = .584). All
patients demonstrated the ability to dorsiflex the foot during the swing phase.
On assessment of muscle strengths using isokinetic
dynamometer at final follow-up, mean peak torque in 60
degrees/sec angular velocity was 7.1 Nm for ankle dorsiflexors, 39.2 Nm for plantarflexors, 9.8 Nm for invertors,
and 7.3 Nm for evertors (Table 3). Mean deficit ratios relative to the contralateral side in 60 degrees/sec angular
velocity were 65.4% for ankle dorsiflexors, 32.8% for plantarflexors, 36.8% for invertors, and 42.9% for evertors.
Radiographic evaluation revealed that there were no significant changes between preoperative and postoperative
foot alignment (Meary angle, calcaneal pitch angle, hindfoot alignment angle, and navicular height) (Table 4).
Comparison of functional and radiologic results with the
normal control group is shown in Table 5.

Table of Contents for the Digital Edition of Foot & Ankle International - June 2017