The Analysis of Biomechanical Properties of Proximal Femur after Implant Removal
Table 2
Radiological and biomechanical data between the specimen over and under 65 years.
Control group
Experimental group
Over 65 years ()
Under 65 years ()
Over 65 years ()
Under 65 years ()
p values†
Age (year)
70.0 ± 1.4
52.4 ± 3.6
78.7 ± 10.3
59.4 ± 4.8
0.376 (Over 65 years) 0.067 (Under 65 years)
(1) Radiological factors
BMD of the neck (mg/cm2)
0.6 ± 0.1
0.9 ± 0.1
0.54 ± 0.14
0.83 ± 0.10
0.494 (Over 65 years) 0.201 (Under 65 years)
BMD of the greater trochanter (mg/cm2)
0.6 ± 0.1
0.9 ± 0.1
0.49 ± 0.15
0.87 ± 0.11
0.178 (Over 65 years) 0.841 (Under 65 years)
BMD of the whole femur (mg/cm2)
1.0 ± 0.1
1.2 ± 0.1
1.23 ± 1.93
1.09 ± 0.17
0.90 (Over 65 years) 0.109 (Under 65 years)
(2) Biomechanical factors
Ultimate load (N)
4742.7 ± 758.5
7712.8 ± 667.9
3115.8 ± 1182.6
5104.2 ± 1300.3
0.027 (Over 65 years) 0.001 (Under 65 years)
Stiffness (N/mm)
920.2 ± 52.4
1060.8 ± 82.5
675.1 ± 158.5
641.1 ± 116.8
0.002 (Over 65 years) 0.012 (Under 65 years)
PFNA ()
DHS ()
PFNA ()
DHS ()
p values‡
Ultimate load (N)
3028.6 ± 1151.3
3203.1 ± 1286.1
5293.7 ± 1202.3
4914.8 ± 1460.8
0.57 (Over 65 years) 0.81 (Under 65 years)
Stiffness (N/mm)
672.2 ± 121.3
675.1 ± 158.5
770.9 ± 94.0
641 ± 116.8
0.96 (Over 65 years) 0.54 (Under 65 years)
For statistical analysis Mann-Whitney test was used and values under 0.05 were considered to be significant. The age, radiological factors, and biomechanical factors between control and experimental group were compared and analyzed statistically according to aged group. ‡For statistical analysis Mann-Whitney test was used and values under 0.05 were considered to be significant. Only PFNA and DHS subgroups over and under 65 years in experimental group were analyzed statistically. The values were described as mean ± standard deviation. Data were reported as mean (standard deviation (SD)). DHS: dynamic hip screw. PFNA-II: proximal femoral nail antirotation. N: newton. cm: centimeter. °: degree. mg: milligram.
