Usefulness of the acromioclavicular joint cross-sectional area as a diagnostic image parameter of acromioclavicular osteoarthritis

Table 1 Comparison of the demographic data of the control and acromioclavicular joint osteoarthritis groups

Variable	Control group, n = 30	ACJO group, n = 35	Statistical significance
Gender (male/female)	9/21	14/21	NS
Age (yr)	57.30 ± 7.56	60.60 ± 9.31	NS
ACJSW (mm)	3.51 ± 0.58	2.02 ± 0.48	P < 0.001
ACJCSA (mm2)	39.88 ± 10.60	18.80 ± 5.13	P < 0.001
Location (Rt/Lt)	13/17	22/13	NS

ACJO: Acromioclavicular joint osteoarthritis; ACJSW: Acromioclavicular joint space width; ACJCSA: Acromioclavicular joint cross-sectional area; NS: Not statistically significant (P > 0.05).

Table 2 Sensitivity and specificity of each acromioclavicular joint cross-sectional area cutoff point

ACJCSA (mm2)	Sensitivity (%)	Specificity (%)
9.75	2.9	100
15.55	22.9	100
18.43	60.0	100
26.14a	91.4	90.0
29.32	94.3	76.7
40.08	100	46.7

^aThe most suitable cutoff point in the receiver operating characteristic curve. ACJCSA: Acromioclavicular joint cross-sectional area.

Table 3 Sensitivity and specificity of each acromioclavicular joint space width cutoff point

ACJSW (mm)	Sensitivity (%)	Specificity (%)
1.41	8.6	100
1.86	34.3	100
2.04	54.3	100
2.37a	88.6	96.7
3.32	97.1	60.0
3.68	100	33.3

^aThe most suitable cutoff value in the receiver operating characteristic curve. ACJSW, acromioclavicular joint space width.