Table 1.

Kappa coefficients for the inter-observer reliability of the Schatzker, AO/OTA and three-column classification

	Schatzker	AO/OTA	Three-column
Observer 1/2	0.576	0.710	0.731
Observer 1/3	0.582	0.635	0.706
Observer 1/4	0.570	0.603	0.890
Observer 2/3	0.513	0.586	0.721
Observer 2/4	0.589	0.510	0.730
Observer 3/4	0.572	0.692	0.818
Mean	0.567	0.623	0.766