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

Table 7 Sub-group analysis regarding the influence of weight bearing on the increase in blood flow by the CO₂ therapy in the fractured limb of patients

Measuring site	Treatment day	Weight bearing (weeks)	n	Mean (range) [95%CI]	p-value (1)	p-value (2)
Fracture level	1	≤5	7	1.490 (1.080–2.846) [0.922–2.057]	0.016	0.77
	1	> 5	12	1.371 (0.970–1.825) [1.215–1.526]	< 0.001	0.77
	14	≤5	7	2.119 (1.158–3.152) [1.439–2.800]	0.016	0.14
	14	> 5	12	1.556 (1.156–2.145) [1.355–1.758]	< 0.001	0.14
	28	≤5	7	2.190 (1.277–3.148) [1.455–2.925]	0.016	0.64
	28	> 5	12	2.107 (1.236–5.100) [1.284–2.929]	< 0.001	0.64
5 cm from the fracture level	1	≤5	7	1.449 (1.060–2.000) [1.177–1.721]	0.016	0.74
	1	> 5	12	1.495 (1.010–2.000) [1.317–1.673]	< 0.001	0.74
	14	≤5	7	2.116 (1.168–2.660) [1.544–2.688]	0.016	0.19
	14	> 5	12	1.703 (1.206–2.346) [1.500–1.906]	< 0.001	0.19
	28	≤5	7	2.397 (1.038–3.431) [1.682–3.112]	0.016	0.047
	28	> 5	12	1.764 (1.215–2.585) [1.510–2.018]	< 0.001	0.047

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 (weight bearing initiated ≤5 weeks versus > 5 weeks)

ISSN: 1471-2474