Table 1.

Characteristics of patients.

	ISI (N = 59)	Non-ISI (N = 91)	P-value
Age, yrs	66.05 ± 9.65	67.77 ± 10.50	0.16
Sex
Men	34 (57.6%)	39 (42.9%)	0.08
Women	25 (42.4%)	52 (57.1%)
Histologic grade
Chondrocyte proliferation
C1	7 (11.9%)	10 (11.0%)	0.92
C2	17 (28.8%)	24 (26.4%)
C3	35 (59.3%)	57 (62.6%)
Granular matrix change
M1	11 (18.6%)	27 (29.7%)	0.13
M2	48 (81.4%)	64 (70.3%)
Pfirrmann grade
P3	7 (11.9%)	18 (19.8%)	0.40
P4	47 (79.7%)	64 (70.3%)
P5	5 (8.5%)	9 (9.9%)

Values are presented as number (%), or mean ± standard deviation unless otherwise indicated.

ISI, intradiscal steroid injection.

Categorical variables were analyzed using the chi-square test.

Continuous variables were analyzed using Student's t-test.