Table 2.

Risk factors and measurements of osseous deformity.

	PHHA*		Version*		SHEAR*		No finger movement at birth
Birth weight	Avg %	P	Avg deg	P	Avg %	P	%	P
>4.5 kg	15 ± 23	0.06	−33 ± 17	0.001	14 ± 16	0.97	65(51–77)	0.82
<4.5 kg	22 ± 21		−26 ± 16		13 ± 11		68(61–74)
Delivery
Instrument†	23 ± 19	0.45	−27 ± 16	0.79	15 ± 12	0.04	69(59–77)	0.91
Spontaneous	20 ± 22		−27 ± 17		11 ± 11		67(59–74)
Shoulder Dystocia
Yes	20 ± 21	0.61	−28 ± 16	0.25	13 ± 12	0.87	68(62–74)	0.47
No	28 ± 10		−19 ± 6		12 ± 14		50(22–78)

All patients suffered permanent obstetric brachial plexus injury. Averages are given with standard deviation and were compared with Mann Whitney U-test. Proportions were compared with Fisher's exact test and provided with 95% confidence intervals.

*PHHA: percent humeral head anterior to the scapular line. Version: degree the glenoid is rotated from normal (retroversion). SHEAR: scapular hypoplasia, elevation, and rotation as measured by percent scapula superior to clavicle.

^†Included forceps, vacuum, or both.