. Author manuscript; available in PMC: 2014 Jul 8.

Published in final edited form as: Am J Sports Med. 2013 Mar 7;41(4):815–825. doi: 10.1177/0363546512475205

Table 4.

Multiple linear regressions relating kinematics and mean contact stress for sectors exhibiting abnormal contact stress following ACL reconstruction.

	Compartment Sector Applied Load Flexion Angle	Lateral middle, central Abduction, Internal 5°			Lateral middle, peripheral Anterior 15°			Medial posterior, central Anterior 30°			Medial anterior, peripheral Anterior 30°
		β	p	r²	β	p	r²	β	p	r²	β	p	r²
Coefficient	Med (kPa/mm)	−140	0.022	0.66			0.59	58	0.001	0.85			0.53
	Med (kPa/mm)	(−223, −57)	0.022					(40, 75)	0.001
	Ant (kPa/mm)							24	0.028
	Ant (kPa/mm)							(8,39)	0.028
	Int (kPa/°)				37	0.009		−25	0.001		−13	0.016
	Int (kPa/°)				(17, 58)	0.009		(−34, −17)	0.001		(−21, −5)	0.016
	Abd (kPa/°)	343	0.034
	Abd (kPa/°)	(118, 574)	0.034

Compartment, sector, applied load, and flexion angle where abnormal stress was observed are identified in the first four rows. Applied loads were: combined abduction and internal rotation moments (Abduction, Internal), and anterior force (Anterior). ° = regression coefficients in units of mm per kilopascal (kPa) or degress per kPa, for translations or rotations, respectively. 95% confidence intervals for the regression coefficients are in parentheses. Med=Medial translation; Ant=anterior translation; Int=internal rotation; Abd=abduction. r2 = adjusted coefficient of determination. A dash (-) indicates p°0.05. Using the first column of results as an example, after reconstruction, contact stress in the middle, central sector of the lateral compartment in response to combined abduction and internal rotation moments (abduction, internal) at 5° flexion increased on average by 140kPa (p=0.022) and 343kPa (p=0.034) for every 1mm decrease in medial translation and 1° increase in abduction, respectively. The coefficient of determination (r2=0.66) indicates that differences in ab/adduction and medial/lateral translation following reconstruction explained 66% of the variation in mean contact stress.