Designing and validating a comparison card method for quantification of glenoid bone defect

To design and investigate a comparison card to evaluate the glenoid bone defect compared with Sugaya method. 33 patients with bony Bankart lesions were included. The comparison card and Sugaya method were performed on two occasions by three participants. The intra-group correlation coefficient (ICC) analysis and the inter-group correlation coefficient analysis of two measurements was performed. The concordance of the two methods was assessed using Bland–Altman analysis. Firstly, the percentage of defect measured by Sugaya method was 10.32 ± 8.38, and the comparison card method was 10.26 ± 8.41, 10.15 ± 8.23, and 10.62 ± 8.48, separately. There was no statistically significant difference ( P > 0.05). The second measurement showed it was 10.37 ± 8.39 for Sugaya method, and 10.23 ± 8.37, 10.15 ± 8.35, 10.54 ± 8.49 for the comparison card, without a statistically significant difference ( P > 0.05). For the comparison card, the intra- and inter-observer ICC values were all > 0.75. In the first measurement, Bland–Altman analysis demonstrated agreement between the two methods (bias, −0.03; SD, 0.48; − 0.97– 0.91; 95% CI, − 0.1999– 0.1413). Agreement was also found between them (bias, 0.07; SD, 0.61; − 1.13– 1.26; 95% CI, − 0.1509– 0.2812) in the second measurement. The comparison card method has similar accuracy with Sugaya method, which is of great reliability and convenience.