Biomechanical study of a low-cost external fixator for diaphyseal fractures of long bones

Table 1 ANOVA results of stiffness, expressed as mean ± SD or median [1st–3rd quartiles], after oblique, transversal, and comminuted fractures

Type of configuration	UUEF1	UUEF2	H3-SR	p value	UUEF1 vs. UUEF 2	UUEF1 vs. H3-SR	UUEF2 vs. H3-SR
					p value	p value	p value
Oblique fracture
Axial stiffness N mm⁻¹	78.3 ± 5.1	119.7 ± 16.8	67.2 ± 8.1	< 0.001	< 0.001	0.3	< 0.001
ML bending stiffness N mm⁻¹	6.2 ± 0.2	8.5 ± 0.7	7.4 ± 0.1	0.004	0.02	0.3	0.3
Torsional stiffness Nm degree⁻¹	1.6 ± 0.3	1.5 ± 0.3	0.9 ± 0.2	0.05	0.8	0.06	0.17
Transversal fracture
Axial stiffness N mm⁻¹	1260.1 ± 63.0	1240.1 ± 139.8	1326.2 ± 141.4	0.516	–	–	–
ML bending stiffness N mm⁻¹	7.9 ± 0.4	6.0 ± 0.4	5.5 ± 0.9	0.009	0.027	0.009	0.6
Torsional stiffness Nm degree⁻¹	1.8 ± 0.3	1.8 ± 0.2	1.4 ± 0.3	0.21	–	–	–
Comminuted fracture
Axial stiffness N mm⁻¹	48.9 ± 3.4	71.8 ± 2.2	35.0 ± 2.1	< 0.001	< 0.001	< 0.001	< 0.001
ML bending stiffness N mm⁻¹	4.4 ± 0.0	4.7 ± 0.3	6.5 ± 0.1	< 0.001	0.2	< 0.001	< 0.001
Torsional stiffness Nm degree⁻¹	1.8 ± 0.4	1.6 ± 0.2	0.8 ± 0.1	0.016	0.7	0.017	0.042

ISSN: 1749-799X