Is It Time to Phase Out the Austin Moore Hemiarthroplasty? A Propensity Score Matched Case Control Comparison versus Cemented Hemiarthroplasty
Table 2
Outcomes compared between cemented versus AMA groups before and after PS matching.
Outcomes before and after PS matching
Before PS matching
After PS matching
Relative risk (95% CI)
NNT (95% CI)
Cemented
AMA
value
Cemented
AMA
value
146 cases
304 cases
128 cases
128 cases
Mean
or (range, SD)
Mean
or (range, SD)
Mean
or (range, SD)
Mean
or (range, SD)
Duration of Surgery
69.1 mins
(21–171, 23.6)
53.7 mins
(20–135, 21.4)
0.000
67.7 mins
(21–139, 22.5)
56.1 mins
(21–135, 21.6)
0.000
General anaesthesia
26.7%
36
17.4%
53
0.022
25.8%
33
18.0%
23
0.131
Received blood transfusion
35.6%
52
38.2%
116
0.602
35.9%
46
32.0%
41
0.510
Died at 1 month
2.1%
3
3%
9
0.577
2.3%
3
0.0%
0
0.082
Died at 3 months
4.8%
7
7.9%
24
0.225
4.7%
6
3.1%
4
0.521
Died at 6 months
8.2%
12
11.8%
36
0.244
8.6%
11
8.6%
11
1.000
Died at 12 months
12.3%
18
19.1%
58
0.074
12.5%
16
15.6%
20
0.474
Total length of stay (mean, SD)
29.3 days
(2–292, 26.9)
29.6 days
(5–130, 16.8)
0.880
29.8 days
(2–292, 28.4)
31.8 days
(12–130, 18.0)
0.508
Fulfill clinical analysis criteria
88.4%
129
86.5%
263
0.585
88.3%
113
91.4%
117
0.410
post-op functional walker
83.7%
108
74.9%
197
0.053
81.4%
92
80.3%
94
0.868
post-op recreational walker
21.7%
28
5.3%
14
0.000
15.9%
18
9.4%
11
0.165
Unable to maintain walking function
42.6%
55
44.9%
118
0.746
45.1%
51
49.6%
58
0.512
post-op thigh pain
6.2%
8
22.4%
59
0.000
7.1%
8
24.8%
29
0.000
3.50 (1.67–7.33)
5.6 (3.7–11.8)
Fulfill complication analysis criteria
80.1
117
81.3
247
0.779
79.7%
102
82.0%
105
0.635
Cracks from attempted AMA
4.3%
5
4.9%
5
Complications
4.3%
5
21.9%
54
0.000
4.9%
5
21.9%
23
0.000
4.47 (1.77–11.30)
5.9 (3.8–12.5)
Loosening
2.6%
3
23.1%
57
0.000
2.9%
3
24.8%
26
0.000
8.42 (2.63–26.95)
4.6 (3.2–7.8)
Loosening before 1 year
2.6%
3
21.9%
54
0.000
2.9%
3
22.9%
24
0.000
7.77 (2.41–25.01)
5.0 (3.5–9.0)
Revision surgeries
3.4%
4
6.9%
17
0.233
3.9%
4
7.6%
8
0.374
Intraoperative crack
0.9%
1
5.3%
13
0.043
1.0%
1
6.7%
7
0.065
Dislocations
0.9%
1
3.2%
8
0.282
1.0%
1
3.8%
4
0.369
Infections
0.9%
1
2.8%
7
0.445
1.0%
1
2.9%
3
0.621
Traumatic periprosthetic fractures
0.9%
1
1.2%
3
1.000
1.0%
1
0.0%
0
0.493
NNT: number needed to treat. Double sided Fisher’s exact test for dichotomous variables. Two-tailed Independent sampled -test for continuous variables.
