Pelvic Incidence: A Predictive Factor for Three-Dimensional Acetabular Orientation—A Preliminary Study

Table 3

The regression equations: direction cosines of acetabulum axis (𝑋,𝑌,𝑍).

Predicted (dependent) variable	Predictor (independent) variable	Regression coefficient	𝑃-level	Standardized coefficient
𝑋 right acetabulum axis (cos𝑋_𝑟)	Intercept	1.100105		0.0
	(cos𝑍_𝑟)	−0.6262985	0.0007	−0.857
	𝑅-squared	0.73
𝑌 right acetabulum axis (cos𝑌_𝑟)	Intercept	−2.764875𝐸−02		0.0
	(cos𝑌_𝑙)	1.161577	0.006	0.76
	𝑅-squared	0.58
𝑍 right acetabulum axis (cos𝑍_𝑟)	Intercept	1.167902		0.0
	(cos𝑋_𝑟)	−0.7642675	0.0006	−0.85
	𝑅-squared	0.739
𝑋 left acetabulum axis (cos𝑋_𝑙)	Intercept	−1.062165		0.0
	(cos𝑍_𝑙)	0.5204172	0.006	0.76
	𝑅-squared	0.58
𝑌 left acetabulum axis (cos𝑌_𝑙)	Intercept	0.2052325		0.0
	(cos𝑌_𝑟)	0.3206353𝐸−03	0.002	0.81
	𝑅-squared	0.67
𝑍 left acetabulum axis (cos𝑍_𝑙)	Intercept	0.790657		0.0
	Pelvic incidence	−2.888895𝐸−03	0.0071	0.75
	𝑅-squared	0.567