Table 1.

Clinical results

Variable	Knees with high tibial osteotomy	Knees without high tibial osteotomy	Correlation (p value)		p Values			Raw observed difference (paired data)	Observed power	Patients needed for power ≥ 0.80	Required difference for power ≥ 0.80 at present number
			Spearman (nonparametric)	Pearson (parametric)	Wilcoxon signed-rank (nonparametric)	Paired t-test (parametric)	F-test indicating inequality of variance
Followup (years)	16.7 ± 2.4 (12.7,21.0)	16.6 ± 2.9 (2.5,22.4)			0.5000	0.2559
Knee score (points)	87.2 ± 15.4 (33,100)	90.3 ± 7.6 (69,100)	0.16 (0.3414)	0.03 (0.8713)	0.5042	0.2364	< 0.0001	3.4 points	0.220	198	8.1 points
Alignment (degrees)	4.6 ± 4.0 (−10,14)	4.6 ± 2.8 (−7,10)	0.50 (0.0017)	0.15 (0.3712)	0.9790	0.9711	0.0399	0.0 degrees	0.050	178608	2.2 degrees
Pain (points)	47.0 ± 8.7 (0,50)	49.1 ± 3.5 (30,50)	0.56 (0.0003)	0.33 (0.0473)	0.0313	0.1252	< 0.0001	2.2 points	0.353	112	3.9 points
Range of motion
Extension (degrees)	−0.1 ± 4.7 (−20,10)	−0.3 ± 3.7 (−20,10)	0.77 (< 0.0001)	0.85 (< 0.0001)	1.0000	1.0000	0.1892	0.0 degrees	0.050	487966	1.2 degrees
Flexion (degrees)	110.6 ± 11.7 (80,130)	112.6 ± 10.2 (90,130)	0.82 (< 0.0001)	0.82 (< 0.0001)	0.0740	0.0779	0.4197	1.9 degrees	0.387	101	3.2 degrees
Function score (points)	70.1 ± 23.2 (0,100)	72.6 ± 20.5 (25,100)	0.99 (< 0.0001)	0.99 (< 0.0001)	0.5000	0.1601	0.1804	0.5 points	0.112	530	2.0 points
Walking score (points)	37.9 ± 15.6 (0,50)	39.2 ± 14.6 (10,50)	0.98 (< 0.0001)	0.99 (< 0.0001)	1.0000	0.3240	0.6862	0.3 points	0.117	487	1.2 points
Stairs score (points)	32.2 ± 11.7 (0,50)	33.4 ± 10.5 (0,50)	0.97 (< 0.0001)	0.99 (< 0.0001)	1.0000	0.3240	0.5460	0.4 points	0.147	342	1.0 points

Values are expressed as means, with ranges in parentheses