Table 1.
Comparison of four component designs
| Design | Head diameter (millimeters) | Shell outer diameter (millimeters) | Posterior horizontal dislocation distances (millimeters) | Correlation of head size to posterior horizontal dislocation distance for each design type |
|---|---|---|---|---|
| Hemispheric fixed bearing | 28 | 48 | 8.6 | |
| 36 | 54 | 11.1 | ||
| 40 | 60 | 12.4 | ||
| 40 | 66 | 12.4 | ||
| Average (SD) | 11.1 (1.8) | p < 0.001; R2 = 0.98; 95% CI, 0.99–1.00 | ||
| Subhemispheric dual mobility | 42 | 48 | 9.2 | |
| 48 | 54 | 10.5 | ||
| 54 | 60 | 12.3 | ||
| 60 | 66 | 14.2 | ||
| Average (SD) | 11.6 (2.2) | p = 0.004; R2 = 0.98; 95% CI, 0.83–0.99 | ||
| Modular Dual Mobility (MDM™) | 36 | 48 | 14.6 | |
| 42 | 54 | 16.5 | ||
| 46 | 60 | 17.8 | ||
| 52 | 66 | 19.6 | ||
| Average (SD) | 17.1 (2.1) | p < 0.001; R2 = 0.99; 95% CI, 0.99–1.00 | ||
| Anatomic Dual Mobility (ADM™) | 42 | 48 | 17.8 | |
| 48 | 54 | 19.8 | ||
| 54 | 60 | 21.8 | ||
| Average (SD) | 19.8 (2.0) | p = 0.0000; R2 = 1 |
MDM™ and ADM™, Stryker Orthopaedics, Mahwah, NJ, USA.