Inter- and intra-rater reliability of vertebral fracture classifications in the Swedish fracture register

Table 2 Distribution of fractures according to the gold standard

			Number of patients	Number of patients with signs of ankylosing spinal disorder
Cervical spine	C1-Th1		50	6
	C1	Posterior arch	2	0
		Burst	5	1
		Lateral mass	1	0
	C2	Odontoid	11	1
		Hangman’s	2	0
		Unclassifiable	4	0
	C3-Th1	Compression	13	3
		Burst	0	0
		Translation/rotation	7	2
		Other	11	0
		Unclassifiable	2	0
Thoracolumbar spine	Th2-L5	Injury through axial compression (A-type injuries)	40	6
		Injury through anterior and posterior structures causing displacement (C-type injuries)	10	10
	Th2-L5 A-type injuries	Wedge shaped compressions	17	2
		Fracture through the middle part of the vertebral body	2	0
		Burst fracture	21	4
	Th2-L5 B-type injuries1	No injury of posterior structures	24	1
		Rupture of the posterior tension band structures through bone	9	4
		Rupture of the posterior ligament	5	0
		Unable to assess	2	1
	Th2-L5 C-type injuries	Hyperextension injury without translation	9	9
		Translation injury/dislocation through bone or disc/ligament	1	1

¹Classification of B-type injuries are only assessed in patients with A-type injuries. C: Cervical vertebra; L: Lumbar vertebra; Th: Thoracic vertebra.