Table 4.

Latent class analysis and surgeons’ accuracy in classifying subtypes of A-type compression fractures (n = 86)

	Likely injury subtype
	A1	A3	A4
	Cluster 1	Cluster 2	Cluster 3
Cluster size (%)	36.3	28.5	35.3
Surgeon 1
1 Wedge/impaction (%)	92.0	6.9	3.8
2 Split/pincer type (%)	7.3	5.1	3.5
3 Incomplete burst (%)	0.3	77.2	0.2
4 Complete burst (%)	0.5	10.8	92.5
Surgeon 2
1 Wedge/impaction (%)	89.8	0.5	0.4
2 Split/pincer type (%)	0.0	0.0	0.0
3 Incomplete burst (%)	9.8	94.9	0.4
4 Complete burst (%)	0.4	4.6	99.3
Surgeon 3
1 Wedge/impaction (%)	90.4	4.4	0.4
2 Split/pincer type (%)	0.0	0.0	0.0
3 Incomplete burst (%)	9.2	91.0	0.5
4 Complete burst (%)	0.4	4.6	99.2
Surgeon 4
1 Wedge/impaction (%)	95.5	5.5	0.4
2 Split/pincer type (%)	0.0	0.0	3.3
3 Incomplete burst (%)	4.1	89.8	0.3
4 Complete burst (%)	0.5	4.7	96.0
Surgeon 5
1 Wedge/impaction (%)	84.7	17.2	0.4
2 Split/pincer type (%)	3.6	0.0	0.0
3 Incomplete burst (%)	0.2	57.7	0.2
4 Complete burst (%)	11.5	25.0	99.4
Classification accuracies
Median (%)	90.4	89.9	99.2
Range	84.7–95.6	57.7–94.9	92.5–99.4

Only one case was clearly identified as an A2 (split/pincer type) fracture by the surgeons. Hence, this analysis was implemented after excluding this case. The model was consistent with three fracture classes including A1, A3 and A4 fractures. Incorrect classification into the A2 category was, however, possible