Table 3. Comparison of ultrasonographic findings of the entheses between groups.

Enthesis		ASG N=100 n (%)	CG N=60 n (%)	p (χ2)	OR
Calcaneal (Achilles) tendon
	Calcification			0.097
	0	52 (52)	30 (50.0)
	1	13 (13)	6 (10.0)
	2	25 (25)	23 (38.3)
	3	10 (10)	1 (1.7)
	Bursitis	10 (10)	5 (8.3)	0.787
	Erosion	17 (17)	0	<0.001
	Power Doppler signal	6 (6)	0	0.084
	Thickening	36 (36)	15 (25.0)	0.148
	Structural change	17 (17)	5 (8.3)	0.123
Plantar fascia
	Calcification			0.296
	0	69 (69)	44 (73.3)
	1	12 (12)	3 (5.0)
	2	17 (17)	13 (21.7)
	3	2 (2)	0
	Erosion	7 (7)	0	0.040
	Power Doppler signal	0	0	1.000
	Thickening	38 (38)	9 (15.0)	0.002	3.473 (0.003)
	Structural change	27 (27)	10 (16.7)	0.133
Proximal patellar tendon
	Calcification			0.470
	0	95 (95)	59 (98.3)
	1	3 (3)	1 (1.7)
	2	2 (2)	0
	3	0	0
	Erosion	0	0	1.000
	Power Doppler signal	0	0	1.000
	Thickening	61 (61)	33 (55)	0.455
	Structural change	3 (3)	3 (5.0)	0.519
Distal patellar tendon
	Calcification			0.822
	0	88 (88)	52 (86.7)
	1	9 (9)	6 (10.0)
	2	2 (2)	2 (3.3)
	3	1 (1)	0
	Bursitis	6 (6)	2 (3.3)	0.711
	Erosion	2 (2)	0	0.528
	Power Doppler signal	1 (1)	0	1.000
	Thickening	69 (69)	37 (61.7)	0.342
	Structural change	8 (8)	9 (15.0)	0.164
Quadriceps femoralis tendon
	Calcification			0.001	5.262 (0.000)
	0	59 (59)	53 (88.3)
	1	14 (14)	3 (5.0)
	2	16 (16)	4 (6.75)
	3	11 (11)	0
	Erosion	2 (2)	0	0.528
	Power Doppler signal	1 (1)	0	1.000
	Thickening	45 (45)	23 (38.3)	0.409
	Structural change	14 (14)	6 (10.0)	0.459
Triceps Brachii	Calcification			0.337
	0	72 (72)	50 (83.3)
	1	10 (10)	5 (8.3)
	2	16 (16)	4 (6.7)
	3	2 (2)	1 (1.7)
	Erosion	0	1 (1.7)	0.375
	Power Doppler signal	0	0	1.000
	Thickening	70 (70)	41 (68.3)	0.825
	Structural change	7 (7)	2 (3.3)	0.331

ASG: ankylosing spondylitis group; CG: control group; OR: odds ratio for belonging to the AS group. The χ² and Fisher tests were used.