Table 4:

Analysis of refractures within 1 year

	Percentage of Patients Having a Second Treatment Session Within 1 y of Initial Procedure			Percentage of Refractured Patients Having a Third Treatment Session Within 1 y of Initial Procedure			Average Available Cement Volumes for Patients Refracuring Within 1 y of Initial Procedure (cc)	Average Time Between Treatment Sessions for Refracturing Patients Within 1 y of Initial Procedures
	No. of Patients Having Initial Procedure	No. Refractured (2nd Procedure)	% Refracturing	No. Refractured (2nd Procedure)	No. Refractured (3rd Procedure)	% of Refractured Patients Having 3rd Procedure		Δt Between 1st and 2nd procedure wk	Δt Between 2nd and 3rd procedure wk
Primary osteoporosis	350	72	20.6	72	23	31.9%	5.18 ± 2.58	11.3	12
Steroid-induced osteoporosis	37	14	37.8	14	6	42.9%	5.97 ± 3.02	7.93	10.8
Total	387	86	22.2	86	29	33.7%
Relative risk			1.84			1.34†
P value			.0163			.3094

* Chi-squared analysis.

^†Fisher exact test.