In vivo measurement of bending stiffness in fracture healing

Table 4 Predictive values of bending stiffness

		Changes in actual bending stiffness between weeks				Coefficients of linear regression analysis of logarithmic data
Target weeks	Parameters	2 to 3	3 to 4	4 to 5	2 to 4	Intercept	Slope
10	r	0.473	0.710	0.765	0.721	0.718	0.419
	r²		0.504	0.585	0.519	0.515
	t	n.s.	3.189	3.752	3.287	3.260	n.s.
	p		0.010	0.004	0.008	0.009
7	r	0.131	0.928	0.873	0.826	0.702	0.364
	r²		0.862	0.763	0.682	0.492
	t		7.058	5.073	4.140	2.785
	p	n.s.	< 0.001	< 0.001	0.003	0.024

Statistical data obtained from linear regression analysis. Future development of bending stiffness can be estimated from the third week on. The best predictive value at the seventh week is obtained from the change in bending stiffness between the third and the fourth week. Prediction of stiffness at the tenth week can best be estimated from change in fracture stiffness between the fourth and fifth weeks. Linear regression analysis of logarithmic transformed stiffness data versus time revealed that predictive values can be obtained from the intercept of the fitted line rather than from the slope.

ISSN: 1475-925X