Scoring system for poor limb perfusion after limb fracture in children

Table 1 Characteristics of the patients

	Normal perfusion, n = 85	Poor perfusion, n = 76	P value
Age in yr			0.532
mean ± SD	6.7 ± 3.2	6.8 ± 2.9
Median (IQR)	6.3 (3.9, 8.7)	6.7 (5.1, 9.0)
Age stratification in yr, n (%)			0.898
≤ 3	12 (14.1)	10 (13.2)
3-6	28 (32.9)	23 (30.3)
> 6	45 (53.0)	43 (56.6)
Sex, n (%)			0.975
Female	30 (35.3)	27 (35.5)
Male	55 (64.7)	49 (64.5)
BMI in kg/m2			0.978
mean ± SD	17.4 ± 3.3	17.5 ± 3.4
Median (IQR)	16.6 (15.2, 18.8)	16.5 (15.2, 18.8)
BMI-for-age, z score			0.939
mean ± SD	0.75 ± 1.79	0.64 ± 1.31
Median (IQR)	0.49 (-0.37, 1.81)	0.52 (-0.32, 1.58)
≥ 1, n (%)	31 (36.5)	28 (36.8)	0.961
< 1, n (%)	54 (63.5)	48 (63.2)
Ethnicity, n (%)			1
Han	84 (98.8%)	75 (98.7%)
Other	1 (1.2%)	1 (1.3%)
Cause of fracture, n (%)			0.422
Fall	82 (96.4)	72 (94.7)
Hit	2 (2.4)	4 (5.3)
Falling	1 (1.2)	0
Method of postoperative fixation, n (%)
Tubular plaster	83 (97.6)	76 (100.0)	0.498
Non-tubular plaster	2 (2.4)	0
Site of fracture, n (%)			0.26
Radius or ulna	21 (24.7)	17 (22.4)
Humerus	57 (67.1)	49 (64.5)
Tibia or fibula	5 (5.9)	10 (13.2)
Femur	2 (2.4)	0
Degree of self-perceived pain, score, n (%)			1
1	3 (5.3)	3 (5.2)
2	53 (93.0)	54 (93.1)
3	1 (1.8)	1 (1.7)
Maximum oxygen saturation of the affected limb among the six follow-ups, n (%)			0.248
≥ 95%	82 (96.5)	76 (100.0)
90%-95%	3 (3.5)	0
< 90%	0	0
Skin temperature of the affected limb, n (%)			0.048
Like the healthy contralateral limb	85 (100.0)	72 (94.7)
Different from the healthy contralateral limb	0	4 (5.3)
Skin color, n (%)			< 0.001
1 = Red	85 (100.0)	45 (59.2)
2 = Dark red	0	31 (40.8)
Degree of swelling of the affected limb, n (%)			1
1 = No	1 (1.2)	0
2 = Presence of mild skin texture	84 (98.8)	76 (100.0)
Range of motion of the affected limb, n (%)			0.103
2 = Mildly restrained	85 (100.0)	73 (96.1)
3 = Restrained with numbness	0	3 (3.9)
Arterial pulsation, n (%)
1 = Present	85 (100.0)	76 (100.0)
Degree of pain of the affected limb
1 = Painless	30 (35.3)	19 (25.0)
Capillary refill time, n (%)
1 = 1-2 s	85 (100.0)	76 (100.0)
2 = < 1 s	0	0
3 = > 2-3 s	0	0

BMI: Body mass index; IQR: Interquartile range; SD: Standard deviation.

Table 2 Univariable analyses for factors associated with poor limb perfusion

	RR	95%CI	P value
Skin temperature of the affected limb			0.048
Like the healthy contralateral limb	1
Different from the healthy contralateral limb	2.181	(1.840, 2.585)
Skin color			< 0.001
1 = Red	1
2 = Dark red	2.889	(2.281, 3.659)
Range of motion of the affected limb			0.103
2 = Mildly restrained	1
3 = Restrained with numbness	2.164	(1.829, 2.561)

CI: Confidence interval; RR: Relative risk.

Table 3 Grading scale based on the key risk factors

Factor	Score
Skin temperature
Like the healthy contralateral limb	1
Different from the healthy contralateral limb	0
Skin color
Red	0
A color other than red	1
Range of motion of the affected limb
Restrained with numbness	1
Restrained without numbness	0

Table 4 Occurrence of the outcome according to each score

Score	Occurrence of the outcome
0	41/126 (32.5%)
1	32/32 (100%)
2	3/3 (100%)