Secondary analysis comparing 1-year and long-term metal ion levels
| Metal ion | Study cohort (n = 35 patients)* | p value | ||
|---|---|---|---|---|
| Mean ± SD | Range | 95% CI | ||
| 1-year chromium level, μg/L (ppm) | 2.46 ± 2.1 | 0.78–11.06 | 1.76–3.16 | 0.16 |
| Unilateral | 2.32 ± 2.0 | 0.78–11.06 | 1.61–3.00 | |
| Bilateral | 3.14 ± 2.0 | 0.92–7.71 | 1.33–4.79 | |
| Long-term chromium level, μg/L (ppm) | 3.03 ± 3.2 | 0.66–16.64 | 1.97–4.09 | 0.08 (unilateral) 0.73 (bilateral) |
| Unilateral | 3.04 ± 3.5 | 0.66–16.64 | 1.74–4.61 | |
| Bilateral | 2.93 ± 1.1 | 1.71–4.72 | 1.92–3.88 | |
| 1-year cobalt level, μg/L (ppm) | 1.73 ± 1.8 | 0.33–9.09 | 1.13–2.33 | 0.09 |
| Unilateral | 1.64 ± 1.9 | 0.33–9.09 | 0.89–2.95 | |
| Bilateral | 2.08 ± 0.9 | 0.94–4.49 | 1.01–3.08 | |
| Long-term cobalt level, μg/L (ppm) | 4.02 ± 8.4 | 0.58–43.68 | 1.24–6.8 | 0.07 (unilateral) 0.06 (bilateral) |
| Unilateral | 4.32 ± 9.3 | 0.58–43.68 | 1.18–7.69 | |
| Bilateral | 2.49 ± 1.3 | 1.51–3.77 | 1.65–3.25 | |
BHR = Birmingham Hip Resurfacing; CI = confidence interval; SD = standard deviation.
↵* Unilateral BHR, n = 29; bilateral BHR, n = 6.