5-year experience of highly cross-linked polyethylene in cemented and uncemented sockets: Two randomized studies using radiostereometric analysis

Figures & data

Figure 1. Graph showing the degree of penetration of the femoral head (proximally) into the cemented acetabular component, in 28 hips with highly cross-linked PE (Durasul) and in 27 hips with conventional (control) PE. The examination was done with the patient in the supine position. Mean ± SE.

Table 1.  Supine examination (at 0–5 years) for the “cemented” study

Wear in various directions (mm)	n	Mean (signed)	95% CI ^a	Range	P-value
Medial (+) / lateral (–)
Highly cross-linked	28	–0.019	–0.06 to 0.02	–0.19 to 0.21	0.3
Control	27	–0.05	–0.09 to 0.01	–0.28 to 0.12
Proximal (+) / distal (–)
Highly cross-linked	28	0.15	0.09 to 0.22	–0.10 to 0.86	< 0.001
Control	27	0.36	0.27 to 0.45	–0.27 to 1.12
Anterior (+) / posterior (–)
Highly cross-linked	28	–0.01	–0.06 to 0.04	–0.25 to 0.27	0.5
Control	27	0.02	–0.03–0.07	–0.22 to 0.32
Three-dimensional
Highly cross-linked	28	0.23	0.17 to 0.29	0.02 to 0.91	< 0.001
Control	27	0.41	0.32 to 0.50	0.14 to 1.21

^a95% confidence interval of the mean

Figure 2. Graph showing the degree of penetration of the femoral head (proximally) into the cemented acetabular component, in 22 hips with highly cross-linked PE (Durasul) and in 24 hips with conventional (control) PE. This examination was done with the patient in the standing position. Mean ± SE.

Table 2.  Standing examination (at 3 months to 5 years) for the “cemented” study

Wear in various directions (mm)	n	Mean (signed)	95% CI ^a	Range	P-value
Medial (+) / lateral (–)
Highly cross-linked	22	0.03	–0.01 to 0.07	–0.16 to 0.24	0.2
Control	24	0.002	–0.03 to 0.04	–0.21 to 0.17
Proximal (+) / distal (–)
Highly cross-linked	22	0.10	0.02 to 0.18	–0.02 to 0.83	< 0.001
Control	24	0.29	0.22 to 0.36	0.03 to 0.69
Anterior (+) / posterior (–)
Highly cross-linked	22	0.05	–0.004 to 0.1	–0.15 to 0.27	0.3
Control	24	0.01	–0.03 to 0.06	–0.16 to 0.25
Three-dimensional
Highly cross-linked	22	0.20	0.13 to 0.27	0.05 to 0.85	0.001
Control	24	0.32	0.26 to 0.39	0.07 to 0.69

^a95% confidence interval of the mean

Figure 3. Graph showing the degree of penetration of the femoral head (proximally) into the uncemented acetabular component, in 19 patients with bilateral total hip arthroplasty. The examination was done with the patient in the supine position. Mean ± SE.

Table 3.  Supine examination (at 0–5 years) for the hybrid study

Wear in various directions (mm)	n	Mean (signed)	95% CI ^a	Range	P-value
Medial (+) / lateral (–)
Highly cross-linked	19	0.001	–0.05 to 0.05	–0.25 to 0.20	0.2
Control	19	–0.04	–0.12 to 0.04	–0.41 to 0.35
Proximal (+) / distal (–)
Highly cross-linked	19	0.08	0.04 to 0.11	–0.02 to 0.24	< 0.001
Control	19	0.34	0.21 to 0.48	0.09 to 1.41
Anterior (+) / posterior (–)
Highly cross-linked	19	0.09	0.02 to 0.17	–0.16 to 0.60	0.4
Control	19	0.03	–0.04 to 0.11	–0.27 to 0.25
Three-dimensional
Highly cross-linked	19	0.20	0.15 to 0.26	0.10 to 0.61	< 0.001
Control	19	0.41	0.30 to 0.52	0.19 to 1.24

^a95% confidence interval of the mean

Table 4.  Standing examination (at 3 months to 5 years) for the hybrid study

Wear in various directions (mm)	n	Mean (signed)	95% CI ^a	Range	P-value
Medial (+) / lateral (–)
Highly cross-linked	12	0.01	–0.07 to 0.10	–0.21 to 0.38	0.4
Control	12	–0.06	–0.15 to 0.03	–0.32 to 0.18
Proximal (+) / distal (–)
Highly cross-linked	12	0.08	–0.07 to 0.23	–0.18 to 0.75	0.001
Control	12	0.28	0.19 to 0.37	0.12 to 0.56
Anterior (+) / posterior (–)
Highly cross-linked	12	0.05	–0.12 to 0.23	–0.46 to 0.63	0.8
Control	12	0.04	–0.09 to 0.16	–0.28 to 0.43
Three-dimensional
Highly cross-linked	12	0.31	0.15 to 0.47	0.09 to 0.96	0.2
Control	12	0.37	0.28 to 0.46	0.17 to 0.59

^a95% confidence interval of the mean