Table 3

The agreement between osteophytes detected by ultrasound and CR, MRI as well as BE in finger joints from patients with HOA

Modality	Osteophyte grade	Ultrasound osteophyte grade				Total	Validity of ultrasound
Modality	Osteophyte grade	0	1	2	3	Total	Validity of ultrasound
MRI^* n=851	0	86	24	4	1	215	PEA 50.4% PCA 96.1%
	1	127	190	109	4	448	Sensitivity 0.83^†
	2	1	17	22	97	171	Specificity 0.75^†
	3	1	56	15	97	117
	Total	215	235	184	217	851
CR^‡ n=3395	0	1544	559	218	55	2376	PEA 57.3% PCA 88.3%
	1	37	169	208	115	529	Sensitivity 0.96^†
	2	4	19	79	211	313	Specificity 0.65^†
	3	0	4	18	155	177
	Total	1585	751	523	536	3395
BE^‡ n=3763	0	1637	484	188	64	2373	PEA 76.6% Sensitiv ity 0.90^†
	1	144	338	393	515	1390	Specificity 0.69^†
	Total	1781	822	581	579	3763	Specificity 0.69^†

↵* Interphalangeal joints of second to fifth finger in dominant hand.
↵† Sensitivity and specificity of ultrasound with the reference being the comparative modality.
↵‡ CMC1, MCP, (P)IP and DIP joints in both hands.
BE, bony enlargement; CR, conventional radiography; HOA, hand osteoarthritis PEA, percentage exact agreement; PCA, percentage close agreement.