The effect of variation in interpretation of the La Trobe radiographic foot atlas on the prevalence of foot osteoarthritis in older women: the Chingford general population cohort

Table 2 Frequency of radiographic foot OA according to Technique 1 and Technique 2 scoring methods

Foot	Joints	Radiographic view	Technique 1%OA^a (n)	Number of ungradable joints^b	Technique 2%OA^a (n)	Technique 1–2 Difference %OA	Total number of participants
Left	1st MTPJ	Dorsoplantar	27.1 (59)	0	27.1 (59)	0.0	218
		Lateral	22.9 (50)	21	13.7 (27)	7.2	197
		Combined	35.8 (78)	0	31.2 (68)	4.6	218
	1st CMJ	Dorsoplantar	45.0 (98)	5	43.2 (92)	1.8	213
		Lateral	10.1 (22)	5	8.5 (18)	1.6	213
		Combined	49.1 (107)	0	45.9 (100)	3.2	218
	2nd CMJ	Dorsoplantar	49.5 (108)	74	30.6 (44)	18.9	144
		Lateral	57.3 (125)	75	27.3 (39)	30.0	143
		Combined	74.3 (162)	21	38.1 (75)	36.2	197
	N1stCJ	Dorsoplantar	19.3 (42)	3	18.1 (39)	1.2	215
		Lateral	11.0 (24)	35	8.7 (16)	2.3	183
		Combined	24.3 (53)	1	21.2 (46)	3.1	217
	TNJ	Dorsoplantar	7.3 (16)	0	7.3 (16)	0.0	218
		Lateral	21.1 (46)	1	19.8 (43)	1.3	217
		Combined	24.3 (53)	0	22.9 (50)	1.4	218
Right	1st MTPJ	Dorsoplantar	33.0 (72)	1	32.7 (71)	0.3	217
		Lateral	27.5 (60)	25	16.1 (31)	11.4	193
		Combined	42.2 (92)	1	35.9 (78)	6.3	217
	1^st CMJ	Dorsoplantar	47.2 (103)	3	46.0 (99)	1.2	215
		Lateral	9.2 (20)	3	7.4 (16)	1.8	215
		Combined	49.5 (108)	0	46.3 (101)	3.2	218
	2nd CMJ	Dorsoplantar	47.7 (104)	80	29.7 (41)	18.0	138
		Lateral	56.4 (123)	76	22.5 (32)	33.9	142
		Combined	70.6 (154)	29	34.4 (65)	36.2	189
	N1stCJ	Dorsoplantar	17.9 (39)	3	16.7 (36)	1.2	215
		Lateral	8.7 (19)	35	6.6 (12)	2.1	183
		Combined	22.5 (49)	2	20.4 (44)	2.1	216
	TNJ	Dorsoplantar	7.8 (17)	0	7.8 (17)	0.0	218
		Lateral	15.1 (33)	1	14.7 (32)	0.4	217
		Combined	18.3 (40)	0	17.9 (39)	0.4	218
Both	ALL 5 joints	Dorsoplantar	81.2 (177)	0	78.4 (171)	2.8	218
		Lateral	83.5 (182)	0	57.3 (125)	26.2	218
		Combined	89.9 (196)	0	83.5 (182)	6.4	218

Key: 1st MTPJ first metatarsophalangeal joint, 1 ^st CMJ the first cuneiform-metatarsal joint, 2nd CMJ the second cuneiform-metatarsal joint, N1stCJ the navicular-first cuneiform joint, TNJ talo-navicular joint
^aPositive diagnosis of radiographic osteoarthritis (AFA grade ≥ 2)
^b to be counted as an ‘ungradable’ joint issues with the scoring of both OP and JSN features in the view being examined had been documented

ISSN: 1757-1146