The relationship between grade of open fracture and time to radiological union.

Table 8: The relationship between grade of open fracture and time to radiological union.

Grade of Open Fracture	Total cases	< 6 wks	% UR	6-12 Wks	% UR	12-18 Wks	% UR	18-24 Wks	% UR	> 24 Wks	% UR	Total	% UR	χ²	P	Def.	%
Open I	500	68	45.6	111	25.6	134	21.0	107	34.5	39	37.9	459	26.1	11.108^*	*0.025*	41	8.2
Open II	587	44	29.5	195	45.0	217	34.1	77	24.8	32	31.1	565	32.1	7.321	0.120	22	3.7
Open III-A	411	37	24.8	73	16.9	174	27.3	93	30.0	19	18.4	396	22.5	5.521	0.238	15	3.6
Open III B	182	Nil	Nil	40	9.2	95	14.9	26	8.4	11	10.7	172	9.8	14.093^*	*0.007*	10	5.5
Open III C	78	Nil	Nil	14	3.2	17	2.7	7	2.3	2	1.9	40	2.3	3.0	0.558	Nil	0.0
Total	1758	149	8.5	433	24.6	637	36.2	310	17.6	103	5.9	1632	92.8			88	5.0
χ²		81.426^*		54.099^*		28^*		40.9^*		42.7^*
P		*< 0.00001*		*< 0.00001*		*< 0.00001*		*< 0.00001*		*< 0.00001*
Amputations												38	2.2
The loss to follow-up including the cases that were referred to other centers and those that died.												88	5.0

%UR = % Union rate for particular type of open fracture, Def. = Defaults.