Table 3.

Comparison of types of craniocervical involvement in the rheumatoid arthritis, spondyloarthritis, and control groups.

	RA (n = 204)	SpA (n = 200)	Healthy control (n = 78)	p: RA vs. SpA vs. control	p: RA vs. control	p: SpA vs. control	p: RA vs. SpA
Female, n (%)	166 (81.4)	124 (62)	55 (70.5)	<0.001	0.048	0.18	<0.001
Age at the time of CT	50 (41–60)	38 (32–47)	46 (18–86)	<0.001	<0.001	0.45	<0.001
Any type of involvement	101 (49.5)	53 (26.5)	4 (5.1)	<0.001	<0.001	<0.001	<0.001
Odontoid process involvement	69 (33.8)	24 (12)	0	<0.001	<0.001	0.001	<0.001
Odontoid process resorption	62 (30.4)	19 (9.5)	0	<0.001	<0.001	0.005	<0.001
Odontoid process pannus	37 (18.1)	9 (4.5)	0	<0.001	<0.001	0.065	<0.001
Atlantoaxial subluxation	17 (8.3)	10 (5)	0	0.022	0.004	0.067	0.018
Spinal cord compression due to AAS	5 (2.5)	1 (0.5)	0	0.12
Vertical subluxation	24 (11.8)	20/197 (10.2)	3 (3.8)	0.13
Brainstem compression due to VS	6 (2.9)	1 (0.5)	0	0.06
Subaxial subluxation	12 (5.9)	4 (2)	1 (1.3)	0.054
Spinal cord compression due to SAS	3 (1.5)	1 (0.5)	0	0.38
Atlantoaxial joint involvement	23/186 (12.4)	13 (6.5)	0	0.002	0.001	0.023	0.32
Atlantooccipital joint involvement	6/187 (3.2)	3 (1.5)	0	0.19

AAS: atlantoaxial subluxation; VS: vertical subluxation; SAS: subaxial subluxation; RA: rheumatoid arthritis; SpA: spondyloarthritis; PsA: psoriatic arthritis.