Topical cutaneous application of carbon dioxide via a hydrogel for improved fracture repair: results of phase I clinical safety trial

Table 8 Sub-group analysis regarding the influence of affected bone on the increase in blood flow by the CO₂ therapy in the fractured limb of patients

Measuring site	Treatment day	Affected bone	n	Mean (range) [95%CI]	p-value (1)	p-value (2)
Fracture level	1	Femur	8	1.518 (1.153–2.846) [1.054–1.982]	0.008	0.59
	1	Tibia	11	1.339 (0.970–1.825) [1.164–1.514]	0.002	0.59
	14	Femur	8	2.162 (1.158–3.152) [1.637–2.687]	0.008	0.015
	14	Tibia	11	1.474 (1.156–2.145) [1.283–1.665]	< 0.001	0.015
	28	Femur	8	2.468 (1.277–4.471) [1.548–3.387]	0.008	0.30
	28	Tibia	11	1.897 (1.236–5.100) [1.153–2.641]	< 0.001	0.30
5 cm from the fracture level	1	Femur	8	1.428 (1.060–2.000) [1.198–1.659]	0.008	0.28
	1	Tibia	11	1.514 (1.010–2.000) [1.321–1.707]	< 0.001	0.28
	14	Femur	8	2.073 (1.168–2.660) [1.578–2.567]	0.008	0.20
	14	Tibia	11	1.697 (1.206–2.346) [1.478–1.917]	< 0.001	0.20
	28	Femur	8	2.167 (1.038–3.431) [1.489–2.845]	0.008	0.48
	28	Tibia	11	1.874 (1.215–2.625) [1.565–2.182]	< 0.001	0.48

Blood flow increase is demonstrated by the ratio of blood flow measured after 20 min of CO₂ therapy to that at pre-treatment. n: number of patients. p-value (1): calculated using Wilcoxon signed rank test with a null hypothesis that the population mean of the blood flow ratio is 1. p-value (2): calculated using Mann–Whitney U test to compare the two groups (femur versus tibia)

ISSN: 1471-2474