Table 3.
Torsional biomechanical testing at 4 weeks
| Mechanical parameter | Experimental groups | |||
|---|---|---|---|---|
| Nondiabetic | Diabetic | |||
| Sham surgery* | Sham surgery* | 0 μg OP-1 + carrier | 25 μg OP-1 + carrier | |
| Failure torque (Nm) | ||||
| Fractured femur | 0.191 ± 0.033 | 0.147 ± 0.016 | 0.161 ± 0.024 | 0.210 ± 0.073 |
| Intact contralateral femur | 0.471 ± 0.027† | 0.227 ± 0.019†,‡ | 0.296 ± 0.021†,‡ | 0.293 ± 0.041‡ |
| Energy to failure (Nm/0) | ||||
| Fractured femur | 1.106 ± 0.211 | 1.169 ± 0.364 | 0.617 ± 0.101 | 0.940 ± 0.462 |
| Intact contralateral femur | 2.728 ± 0.255 | 1.328 ± 0.095 | 1.911 ± 0.282 | 1.874 ± 0.263 |
| Torsional stiffness (Nm/0) | ||||
| Fractured femur | 0.024 ± 0.008 | 0.021 ± 0.005 | 0.027 ± 0.004 | 0.045 ± 0.013 |
| Intact contralateral femur | 0.046 ± 0.005 | 0.026 ± 0.007 | 0.032 ± 0.005 | 0.033 ± 0.006 |
Values are given as mean and standard error of the mean; *control animals in which closed fracture was created and fracture site was opened then closed without treatment; †intact femurs greater than fractured femurs for same experimental group (p < 0.012); ‡less than intact nondiabetic sham surgery controls (p < 0.009); OP-1 = osteogenic protein-1.