Table 2.

Comparison of cartilage thickness measurements by US and JSW, assessed by radiography.

	Radiography, Right: n = 73; Left: n = 74	Ultrasound, Right: n = 74; Left: n = 72	Correlation Coefficient^{^*}	Cronbach’s Alpha Coefficient	Intraclass Correlation Coefficient^**
Right knee spots
Intercondylar		2.95 (± 0.7)
Medial condyle	6.73 (± 1.6)	2.82 (± 0.8)	0.76	0.772	0.629
Lateral condyle	6.96 (± 1.2)	3.04 (± 0.8)	0.52	0.628	0.458
Left knee spots
Intercondylar		3.00 (± 0.7)
Medial condyle	6.9 (± 1.7)	2.81 (± 0.9)	0.81	0.838	0.721
Lateral condyle	6.75 (± 1.2)	3.09 (± 0.9)	0.55	0.696	0.534
Right
MCP	2.2 (± 0.53)	1.14 (± 0.48)	0.82	0.893	0.806
PIP	1.44 (± 0.29)	0.56 (± 0.20)	0.50	0.582	0.411
Left
MCP	2.23 (± 0.52)	1.18 (± 0.47)	0.86	0.927	0.863
PIP	1.40 (± 0.30)	0.56 (± 0.20)	0.55	0.563	0.392

Cartilage thickness given as mm, mean (± SD).
↵* Spearman’s rank: p < 0.001.
↵** Intraclass correlation coefficient: p < 0.001. US: ultrasound; JSW: joint space width; MCP: metacarpophalangeal; PIP: proximal interphalangeal.