Table 2.

Alignment of the interphalangeal (IP) and metacarpophalangeal (MP) joints of the main thumb according to the system of Wu et al. [11]

IP and MP alignment		Deviation level				Total
		No	IP	MP	Both
Wu et al. type C3 CTD subtypes	I	53 (100)	-	-	-	53 (24.0)
	II	-	-	136 (100)	-	136 (61.5)
	III	-	-	21 (100)	-	21 (9.5)
	IV	-	2 (18.2)	-	9 (81.8)	11 (5.0)
Total		53 (24.0)	2 (0.9)	157 (71.0)	9 (4.1)	221
chi-squared		300.430				-
p value		0.000				-