Table 2.
Porcine Spines: Change in Range of Motion (ROM) in Flexion-Extension (FE), Lateral Bending (LB), and Axial Rotation (AR), With Mean and SD Expressed as Percent (%).a
| ROM (% Change) | Posterior Concave Distraction Device vs Untreated | Rigid PS vs Untreated | Rigid PS vs Posterior Concave Distraction Device | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Porcine | Mean | SD | P | Mean | SD | P | Mean | SD | P |
| FE | |||||||||
| Proximal adjacent | 2.1 | 7.4 | 1.000 | 1.0 | 6.3 | 1.000 | −1.0 | 2.8 | 1.000 |
| Bridged | −55.9 | 7.1 | <.001 | −94.0 | 23.0 | .001 | −86.4 | 46.6 | .018 |
| Distal adjacent | −7.7 | 5.5 | .056 | −8.3 | 7.1 | .105 | −0.6 | 6.4 | 1.000 |
| LB | |||||||||
| Proximal adjacent | −4.7 | 6.9 | .455 | −5.8 | 3.9 | .045 | −1.1 | 6.8 | 1.000 |
| Bridged | −17.9 | 7.7 | .007 | −92.2 | 26.2 | .001 | −90.4 | 28.0 | .002 |
| Distal adjacent | −4.1 | 4.8 | .268 | −6.8 | 7.7 | .244 | −2.8 | 6.4 | .970 |
| AR | |||||||||
| Proximal adjacent | 0.7 | 10.4 | 1.000 | −9.4 | 22.1 | 1.000 | −10.0 | 14.6 | .459 |
| Bridged | −3.9 | 3.3 | .104 | −86.9 | 23.2 | .001 | −86.3 | 21.8 | .001 |
| Distal adjacent | 17.9 | 18.2 | .183 | 23.9 | 15.4 | .038 | 5.1 | 17.3 | 1.000 |
aData of the 3 bridged motion segments is averaged. Boldfaced values indicate statistical significance (P < .05). Rigid PS: bilateral rigid pedicle screw-rod instrumentation.