Table 1.
The biomechanical behavior of the over-drilled angle-stable IM nail was compared to a traditional interlocked IM nail and an anglestable IM nail without over-drilling. See Figure 1 and text for additional details.
| Axial Compression (N/mm) | Toggle (°) | Total Angular Deformation (°) | Positive Stiffness (N-mm/°) | Negative Stiffness (N-mm/°) | Bending Stiffness (N-mm/mm) | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Prefatigue | Postfatigue | Prefatigue | Postfatigue | Prefatigue | Postfatigue | Prefatigue | Postfatigue | Prefatigue | Postfatigue | Prefatigue | Postfatigue | |
| Traditional Nail (Figure 1(a)) | 1,171±15, 1%#@ | 1,334±14.9, 11%@ | 4.6±1.3, 29%@ | 4.7±1.4, 30%@ | 8.2±1.19, 14%@ | 8.3±1.29, 16%@ | 830±71, 9%@ | 843±79, 9%@ | 809±16, 2%@ | 802±45, 6%@ | 13,141±1,175, 8.9%∧ | -§ |
| Angle-Stable Nail w/o overdrilling (Figure 1(b)) | 1,445±28, 2%*@ | 1,664±201, 12%*@ | 0*@ | 0*@ | 2.7±0.1, 6%*@ | 2.6±0.1, 2%*@ | 1,137±68, 6%*@ | 1,185±13, 1%*@ | 1,157±63, 5%*@ | 1,189±15, 1% *@ | 11,967±2,675, 22.3%∧ | -§ |
| Overdrilled Angle-Stable Nail (Figure 1(c)) | 1351±167, 12%* | 1461±123, 8%! | 0* | 0* | 4.3±0.2, 6%*! | 4.2±0.2, 5%*! | 762±74, 10%! | 774±73, 9%! | 765±78, 10%! | 801±83, 10%! | 11,133±1,221, 11% | 10,723±497, 4.6% |
*
Significantly different than traditional nail;
!
Significantly different than angle stable nail w/o over-drilling;
#
Data is presented as mean ± 1 SD (standard deviation); the coefficient of variation (ratio of SD to mean) is presented as an additional measure of data dispersion;
@
From Garlock et al.,
∧
From Donovan et al.;
§
Not tested