Malfunctions of interspinous process devices.
| Implant Malfunctions | Across Implantsa | Within Implantsb | |||||
| Coflex | Superion | X-Stop | Overall, % (n) | Coflex | Superion | X-Stop | |
| Spindle cap malfunction during deployment | 0.0% | 100.0% | 0.0% | 52.1% (195) | 0.0% | 53.4% | 0.0% |
| Broke on deployment or broke off of inserter/connector | 0.0% | 100.0% | 0.0% | 35.8% (134) | 0.0% | 36.7% | 0.0% |
| Fragmentation/bending | 24.2% | 75.8% | 0.0% | 8.8% (33) | 100.0% | 6.8% | 0.0% |
| Not specified | 0.0% | 91.7% | 8.3% | 3.2% (12) | 0.0% | 3.0% | 100.0% |
↵a Across group analysis demonstrates that the proportion of total implant malfunctions for a given malfunction type is attributed to each implant manufacturer.
↵b Within groups analysis demonstrates the contribution of malfunction type to the total pool of implant malfunctions for a given manufacturer/implant.