Assessing the accuracy of arthroscopic and open measurements of the size of rotator cuff tears: A simulation-based study

Table 1 The dimensions of the simulated tears measured by the surgeons (Layouts in Figure 2)

ID	Description	Standardized technique	Computerized dimensions (mm)
A1	Basis length	Anterior to posterior	15.2
A2	Contour length	Anterior to posterior	53.5
A3	Height	Medial to lateral, most distal length	22.9
B1	Basis length	Anterior to posterior	20.3
B2	Contour length	Anterior to posterior	31.9
B3	Height	Medial to lateral, most distal length	10.2
C1	Medial contour length	Upper in Figure 2	31.9
C2	Lateral contour length	Lower in Figure 2	31.6
C3	Medial to lateral height	Short height in Figure 2	7.6
C4	Anterior to posterior height	Long height in Figure 2	31.0

Table 2 Overall mean difference between the groups of measurements

Groups	mean difference, mm	P1 value
Arthroscopic vs computerized	-2.4 ± 3.2	< 0.001
Arthroscopic vs open	-2 ± 2.6	< 0.001
Open vs computerized	-0.4 ± 1.6	0.014

¹Wilcoxon signed ranks test, level of significance P = 0.016 (Bonferroni correction).

Table 3 Comparison of mean differences between arthroscopic versus computerized, and arthroscopic and open measurements in millimeters (mean ± SD)

Dimension	Arthroscopic vs computerized	P1 value	Arthroscopic vs open	P1 value
A1	-0.5 ± 1.2	0.92	-0.3 ± 1.2	0.92
A2	-7.6 ± 5.8	0.03	-3.7 ± 4.9	0.12
A3	-2.1 ± 2.7	0.17	-2.0 ± 2.5	0.14
B1	-2.3 ± 1.9	0.03	-1.9 ± 1.9	0.04
B2	-3.1 ± 3.1	0.12	-3.2 ± 2.3	0.04
B3	-0.7 ± 0.8	0.05	-0.5 ± 0.8	0.20
C1	-1.8 ± 1.6	0.05	-2.5 ± 2.4	0.05
C2	-1.8 ± 1.8	0.05	-2.8 ± 2.1	0.03
C3	-0.1 ± 0.5	0.91	-0.3 ± 0.4	0.18
C4	-4.5 ± 3.1	0.03	-3.1 ± 3.5	0.06

¹Wilcoxon Signed Ranks Test, level of significance P = 0.05.