ABSTRACT
Objective To evaluate intra-and interobserver reliability of analysis of lower limb alignment on DR digital images using AutoCAD.Methods Angles on AP view and long leg view were measured three times by two trained observers separately using these two methods in 140 knees.The intra-and interobserver intraclass correlation coefficients with 95% CIs of two methods were calculated and compared with Fisher z transformation and Z test.Paired t test was used in comparing time consumption.Results For AutoCAD method,inter ICCs were 0.942? 0.993 ,intra ICCs were 0.937～0.999.For X-ray films method,inter ICCs were 0.736～0.981,intra ICCs were 0.759～0.951.Corresponding ICCs of AutoCAD method were higher than those of X-ray films method,most of which had significant differences(P<0.01).The consuming time of two observers in measuring one knee using AutoCAD method was 89.6 seconds and 94.3 seconds shorter than those using X-ray films method respectively.Both had significant differences(P<0.01).Conclusion It was a fast reliable method to assess lower limb alignment on DR digital images using AutoCAD.