Table 1. Subject demographics of each group
|
R-RHK
n=6, 6 knees
|
uniCR
n=4, 4 knees
|
bilCR
n=10, 20 knees
|
|
|
|
|
Mean± SD
(95% CI)
|
Mean± SD
(95% CI)
|
Mean± SD
(95% CI)
|
F value
|
P-value
|
η2
|
Age
|
73.00±6.83
(62.13- 83.87)
|
67.67±0.58
(66.23- 69.10)
|
71.67±5.13
(58.91- 84.41)
|
0.22
|
0.81
|
0.02
|
Post surgery TKA (months)
|
22.00±17.37
(0.42- 43.58)
|
9.60±3.28
(5.52-13.69)
|
10.80±2.68
(7.47- 14.13)
|
3.67
|
0.05
|
0.24
|
The number of using AS bearing
|
-
|
3/4 knees
|
12/20 knees
|
-
|
-
|
-
|
Height (cm)
|
150.88±5.32
(144.26- 157.50)
|
154.20±8.00
(144.26- 164.14)
|
145.92±4.60
(140.21- 151.63)
|
1.22
|
0.31
|
0.11
|
Weight (kg)
|
65.28±9.15
(53.92- 76.64)
|
63.20±7.39
(54.03- 72.38)
|
58.00±10.40
(45.09- 70.92)
|
0.03
|
0.98
|
0.00
|
BMI (kg/m2)
|
28.56±2.47
(25.49- 31.63)
|
26.54±1.72
(24.40- 28.67)
|
27.20±4.54
(21.26- 32.84)
|
0.57
|
0.58
|
0.05
|
TKA, total knee arthroplasty; BMI, body mass index; R-RHK, revision TKA was due to aseptic loosening with the rotator hinge knee type; uniCR, unilateral primary TKA with the cruciate retaining type; bilCR, bilateral primary TKA with the cruciate retaining type; CI, confidence interval
Table 2. Spatio- temporal parameters of each group
|
R-RHK
|
uniCR
|
bilCR
|
|
|
|
|
Mean± SD
(95% CI)
|
Mean± SD
(95% CI)
|
Mean± SD
(95% CI)
|
F value
|
P-value
|
η2
|
Gait speed (m/s)
|
0.79±0.02
(0.77- 0.82)
|
0.99±0.04
(0.94- 1.05)
|
1.02±0.14
(0.80- 1.23)
|
9.31
|
<0.01
|
0.47
|
Cadence (steps/min)
|
114.50±15.54
(89.76- 139.24)
|
112.00±2.44
(108.10- 118.90)
|
119.75±12.50
(99.86- 139.64)
|
1.31
|
0.29
|
0.11
|
Step length (cm)
|
43.50±7.55
(31.49- 55.51)
|
54.50±3.70
(48.62- 60.38)
|
52.14±5.53
(48.94- 55.34)
|
6.69
|
0.01
|
0.39
|
Step width (cm)
|
17.00±3.56
(11.34- 22.66)
|
14.67±4.08
(10.38- 18.95)
|
14.67±4.37
(10.08- 19.25)
|
2.48
|
0.11
|
0.18
|
R-RHK, revision TKA was due to aseptic loosening with the rotator hinge knee type; uniCR, unilateral primary TKA with the cruciate retaining type; bilCR, bilateral primary TKA with the cruciate retaining type; CI, confidence interval
Among the spatiotemporal parameters, gait speed in the R-RHK group was significantly slower and step length in the R-RHK group was significantly longer than those in the uniCR and bilCR groups.
Table 3. Kinetics and kinematics data during gait
|
R-RHK
|
uniCR
|
bilCR
|
|
|
|
|
Mean± SD
(95% CI)
|
Mean± SD
(95% CI)
|
Mean± SD
(95% CI)
|
F value
|
P-value
|
η2
|
maximum flexion angle (deg)
|
40.24±7.07
(31.47- 49.01)
|
41.21±9.20
(29.78- 52.63)
|
35.42±7.13
(26.57- 44.28)
|
0.24
|
0.79
|
0.01
|
minimum flexion angle (deg)
|
9.30±8.91
(-1.76- 20.36)
|
9.61±4.73
(3.73- 15.50)
|
5.20±5.74
(-1.93- 12.33)
|
0.92
|
0.41
|
0.05
|
maximum varus angle (deg)
|
1.65±2.14
(-1.76- 5.06)
|
-0.64±2.75
(-5.01- 3.72)
|
1.50±1.81
(-1.39- 4.39)
|
0.55
|
0.58
|
0.03
|
maximum inner rotation angle (deg)
|
-2.11±15.13
(-26.20- 21.98)
|
-8.98±4.75
(-16.54- -1.41)
|
-5.86±7.18
(-17.28- 5.57)
|
1.17
|
0.32
|
0.06
|
maximum external rotation angle (deg)
|
10.99±8.57
(-2.67- 24.60)
|
15.37±5.09
(7.26- 23.47)
|
11.78±5.80
(2.54- 21.01)
|
1.41
|
0.26
|
0.07
|
amount of rotation angle (deg)
|
5.60±3.30
(0.35- 10.86)
|
6.40±2.88
(1.81- 10.98)
|
5.92±2.47
(1.99- 9.85)
|
0.26
|
0.77
|
0.01
|
KAM(Nm/kg)*
|
0.55±0.34
(0.18- 0.57)
|
0.37±0.16
(0.18- 0.57)
|
0.35±0.11
(0.22- 0.48)
|
0.74
|
0.71
|
0.07
|
R-RHK, revision TKA was due to aseptic loosening with the rotator hinge knee type; uniCR, unilateral primary TKA with the cruciate retaining type; bilCR, bilateral primary TKA with the cruciate retaining type; CI, confidence interval; KAM, maximum knee adduction moment during stance phase
The knee joint angles were compared among the three groups, the R-RHK , the uniCR, and the bilCR groups by using analysis of variance (ANOVA) and the post-hoc Tukey test.
*KAM was compared inter groups by analysis of covariance (ANCOVAs) controlling for gait speed.
Table 4. Kinetics and kinematics data from initial contact to loading response
|
R-RHK
|
uniCR
|
bilCR
|
|
|
|
|
Mean± SD
(95% CI)
|
Mean± SD
(95% CI)
|
Mean± SD
(95% CI)
|
F value
|
P-value
|
η2
|
tibialis translation (mm)
|
1.46±0.52
(0.81- 2.10)
|
1.45±2.20
(-1.29- 4.18)
|
0.99±1.63
(-1.02- 3.01)
|
0.01
|
0.99
|
0.00
|
amount of tibial rotation angle (deg)
|
0.98±1.50
(-1.39- 3.36)
|
1.69±2.51
(-2.31- 5.69)
|
0.67±0.48
(-0.1- 1.40)
|
1.26
|
0.30
|
0.07
|
R-RHK, revision TKA was due to aseptic loosening with the rotator hinge knee type; uniCR, unilateral primary TKA with the cruciate retaining type; bilCR, bilateral primary TKA with the cruciate retaining type; CI, confidence interval
Tibial translation; The plus means anterior.
Rotation; The plus means internal rotation