The Analysis of Biomechanical Properties of Proximal Femur after Implant Removal
Table 1
Anatomical, radiological, and biomechanical data of the PFNA-II and DHS groups.
Control group (intact femur)
Experiment group
p value†
PFNA-II group
DHS group
(1) Anatomical factors
Femoral head diameter (cm)
4.8 ± 0.3
4.69 ± 0.30
4.70 ± 0.32
0.874
Femoral neck diameter (cm)
3.2 ± 0.2
3.20 ± 0.43
3.22 ± 0.39
0.395
Shaft diameter (cm)
2.6 ± 0.1
2.57 ± 0.20
2.60 ± 0.21
0.910
Neck-shaft angle (°)
132.6 ± 1.8
133.93 ± 2.25
133.13 ± 3.29
0.395
(2) Radiological factors
BMD of the whole femur (mg/cm2)
1.1 ± 0.2
0.94 ± 0.25
1.39 ± 1.97
0.182
BMD of the greater trochanter (mg/cm2)
0.7 ± 0.2
0.67 ± 0.22
0.67 ± 0.25
0.738
BMD of the neck (mg/cm2)
0.7 ± 0.2
0.68 ± 0.18
0.67 ± 0.20
0.67
(3) Biomechanical factors
Ultimate load (N)
6227.8 ± 1694.1
4085.6 ± 1628.03
4001.9 ± 1588.3
0.014
Stiffness (N/mm)
990.5 ± 99.8
718.3 ± 117.2
656.3 ± 155.3
<0.001
For statistical analysis Kruskal-Wallis test was used and values under 0.05 are considered significant. The values were described as mean ± standard deviation. DHS and PFNA-II mean dynamic hip screw and proximal femoral nail antirotation. N, cm, (°), and mg mean newton, centimeter, degree, and milligram.
