Table 1.

Intra-observer and inter-observer reliability for all five lateral tibial slope measurement methods.

	Intra-observer		Inter-observer
	Typical Error	ICC	Typical Error	ICC
Midpoint method, 20 cm	± 0.92° (CI 0.75° - 1.18°)	0.92	± 0.86° (CI 0.44° - 0.99°)	0.85
Midpoint method, 15 cm	± 1.08° (CI 0.89° - 1.39°)	0.9	± 0.85° (CI 0.43° - 0.97°)	0.87
Midpoint method, 10 cm	± 1.18° (CI 0.97° - 1.52°)	0.89	± 1.08° (CI 0.55° - 1.23°)	0.79
Circle method	± 0.84° (CI 0.69° - 1.08°)	0.92	± 0.75° (CI 0.38° - 0.86°)	0.93
Full tibia method	± 0.64° (CI 0.53° - 0.83°)	0.91	± 0.89° (CI 0.45° - 1.01°)	0.85

Abbreviations: ICC: Intra-class coefficients; CI: 95% confidence intervals