Biomechanical analysis of a synthetic femoral spiral fracture model: Do end caps improve retrograde flexible intramedullary nail fixation?

Table 1 Summary of the results 2 ESIN vs. 2 ESIN with End Caps

	2 Titanium Nails (2E)		2 Titanium Nails with End Caps (2EEC)	p-value
	Mean value (SD)		Mean value (SD)
2 ESIN with End Caps *more* stable than 2 ESIN
Posterior-anterior	1.78 (1.31) Nm/mm	<	4.11 (2.24) Nm/mm	< 0.001
2 ESIN with End Caps *less* stable than 2 ESIN
Anterior-posterior	0.77 (0.29) Nm/mm	>	0.27 (0.08) Nm/mm	< 0.001
Medial-lateral	1.10 (0.40) Nm/mm	>	0.80 (0.35) Nm/mm	< 0.01
Lateral-medial	0.86 (0.33) Nm/mm	>	0.53 (0.13) Nm/mm	< 0.001
Internal Rotation	0.14 (0.04) Nm/°	>	0.11 (0.01) Nm/°	< 0.05
No statistical significant difference
External Rotation	0.32 (0.18) Nm/°	~	0,37 (0.11) Nm/°	0.13
Compression in 9°-Position	2.18 (1.37) mm	~	1.29 (1.61) mm	0.20