Table 3.

Statistical comparison of MRI features in different hip pain subgroups.

AS -hip pain	Number of individuals	BME lesions in trochanters	Superficial BME lesions in femoral heads	Superficial BME lesions in acetabula	Deep BME lesions in femoral heads	Deep BME lesions in acetabula	Cysts in femoral heads	Cysts in acetabula
Minimal/mild a	103	8%*	12%*	13%*	5%*	6%*	0%	4%*
Moderate	142	3%	13%	11%	3%	1%	0%	1%
Severe	55	1%	31%#	12%	21%#	6%	0%	5%

HC, Healthy control; AS, Ankylosing Spondylitis; OA, Osteoarthritis; BME, bone marrow edema. * indicates that the particular minimum/mild hip pain group value is statistically higher than the healthy control group; # represents statistically significant difference between the severe hip pain group and the minimal/mild hip pain; ^a42% of this group has at least one MRI sign. All MRI lesions were observed with the STIR sequences.