Small and similar amounts of micromotion in an anatomical stem and a customized cementless femoral stem in regular-shaped femurs

Figures & data

Figure 1. The implants: the ABG-I stem on the left and the Unique stem on the right.

Figure 2. Consort flow chart.

Table 1. Study samples

	ABG-I	Unique
No. of patients	43	47
Age	53	55
Male/female	14/29	19/28
Primary osteoarthritis	21	31
Hip dyplasia	19	9
Sequelae Perthes’ disease	1	3
Posttraumatic	1	3
Avascular head necrosis	1	1

Table 2. Migration data and RSA precision data measurement at five-year follow-up. The p-values refer to statistical testing of differences in motion between the 2 types of stem and the effect of time versus motion

	Implant	Median 5-year	Range	95%CI of the median	p-value, difference in motion	Difference in motion 95%CI	p-value, time vs. motion	RSA precision
x-rot [deg]	ABG-I	–0.14	–1.10 to 1.02	–0.26 to –0.07	0.64	–0.14 to 0.09	0.03	0.52
	Unique	0.02	–1.67 to 1.45	–0.09 to 0.06
y-rot [deg]	ABG-I	0.15	–0.89 to 2.93	–0.01 to 0.36	0.41	–0.14 to 0.33	0.08	1.36
	Unique	–0.08	–1.66 to 4.43	–0.30 to 0.56
z-rot [deg]	ABG-I	–0.12	–0.87 to 0.58	–0.17 to –0.08	0.31	–0.04 to 0.11	0.01	0.24
	Unique	–0.20	–0.94 to 0.49	–0.35 to –0.14
x-trans [mm]	ABG-I	–0.03	–0.41 to 0.33	–0.10 to 0.03	0.20	–0.08 to 0.02	0.4	0.19
	Unique	–0.05	–1.02 to 0.78	–0.13 to 0.04
y-trans [mm]	ABG-I	–0.03	–0.50 to 0.27	–0.09 to –0.01	0.15	–0.07 to 0.42	0.02	0.21
	Unique	–0.13	–5.36 to 0.59	–0.18 to –0.05
z-trans [mm]	ABG-I	0.06	–0.36 to –0.78	0.01 to 0.11	0.32	–0.05 to 0.14	<0.01	0.37
	Unique	0.07	–0.80 to 1.94	0.01 to 0.16

Figure 3. Translation along the y-axis. The whiskers show the 10th and 90th percentiles.

Figure 4. Rotation around the y-axis.

Figure 5. Translation along the z-axis.

Figure 6. Rotation around the z-axis.

Figure 7. Translation along the x-axis.

Figure 8. Rotation around the x-axis