Comparison of theoretical fixation stability of three devices employed in medial opening wedge high tibial osteotomy: a finite element analysis

Table 4 Stresses along the screw channels in bone

Fixation	Screw channel (from proximal)	Surface of the channel	_maxσ_x(compression stress)	_minσ_x(tensile stress)
First generation Puddu plate	1	Upper	2.16
	1	Lower		2.07
	2	Upper		2.57
	2	Lower		4.6
Second generation Puddu plate	1	Upper	1.50
	1	Lower		6.04
	2	Upper		1.47
	2	Lower		5.23
TomoFix with bone graft	1	Upper		0.34
	1	Lower		0.41
	2	Upper	0.78
	2	Lower		2.58
	3	Upper		0.28
	3	Lower		1.20
	4	Upper		0.55
	4	Lower		1.08
	5	Upper		0.34
	5	Lower		0.87
	6	Upper		0.25
	6	Lower		0.48
TomoFix without bone graft	1	Upper		0.53
	1	Lower		0.58
	2	Upper	0.78
	2	Lower		7.15
	3	Upper		2.20
	3	Lower		4.70
	4	Upper		1.24
	4	Lower		2.10
	5	Upper		0.46
	5	Lower		0.98
	6	Upper		0.35
	6	Lower		0.76

Note: the values exceeding the maximum allowable threshold for the stresses on the screw are in bold.

ISSN: 1471-2474