Table 1

Characteristics of enrolled subjects.

CharacteristicNon-Surgical Management (n=46)SI Joint Fusion (n=102)P-value*
Age, mean (SD, range)
  ≥ 65 years old, n (%)
54.0 (11.0, 29.5-76.0)
8 (17.4%)
50.2 (11.4, 25.6-71.7)
10 (9.8%)

0.0561
Women, n (% female)28 (60.9%)75 (73.5%)0.1279
Race, n (%)
 White
 Black
 American Indian
 Other

43 (93.5%)
2 (4.3%)
0 (0%)
1 (2.2%)

97 (95.1%)
3 (2.9%)
1 (1.0%)
1 (1.0%)


0.6759
Ethnicity
 Hispanic or Latino, n (%)

4 (8.7%)

4 (3.9%)

0.2552
Body mass index, mean(SD, range)30.6 (6.6, 19.4-48.9)30.3 (6.5, 14.1-49.5)0.7961
Smoking status, n (%)
 Current smoker
 Former smoker
 Never smoker

3 (6.5%)
13 (28.3%)
30 (65.2%)

26 (25.5%)
30 (29.4%)
46 (45.1%)

0.0117
Ambulatory without assistance (n,%)41 (89.1%)89 (87.3%)1.0
Work status (n,%)
 Working full time
 Working part time
 Not working, student
 Not working, retired
 Not working due to back pain
 Not working, other reason

21 (45.7%)
4 (8.7%)
0 (0%)
9 (19.6%)
8 (17.4%)
4 (8.7%)

45 (44.1%)
9 (8.8%)
1 (1.0%)
21 (20.6%)
20 (19.6%)
6 (5.9%)



0.9850
Prior lumbar fusion (n,%)17 (37.0%)39 (38.2%)1.0
Underlying diagnosis
 Degenerative sacroiliitis
 Sacroiliac joint disruption

40 (87.0%)
6 (13.0%)

88 (86.3%)
14 (13.7%)

1.0
Years of pain, mean (range)5.0 (0.48-38.9)7.0 (0.5-40.7)0.1270
Pain syndrome
 Pain began peripartum
 Pain radiates down leg
 Groin pain
 Pain worse with sitting
 Pain worse with rising
 Pain worse with walking
 Pain worse with climbing stairs
 Pain worse descending stairs

4 (8.7%)
41 (89.1%)
29 (63.0%)
41 (89.1%)
41 (89.1%)
42 (91.3%)
41 (89.1%)
37 (80.4%)

8 (7.8%)
89 (87.3%)
60 (58.8%)
89 (87.3%)
88 (86.3%)
87 (85.3%)
93 (91.2%)
82 (80.4%)

0.2287
1.0
0.7177
1.0
0.7926
0.4285
0.7638
1.0
Prior treatments
 Physical therapy
 Steroid SI joint injection
 RF ablation

36 (78.3%)
42 (91.3%)
4 (8.7%)

71 (69.6%)
85 (83.3%)
20 (19.6%)

0.3247
0.3082
0.1467
Taking opioids (n,%)29 (63.0%)69 (67.6%)0.5798
Proportion with lumbar stenosis (n,%)7 (15.2%)15 (14.7%)0.8215
Proportion with hip diagnosis (n,%)2 (4.3%)13 (12.7%)0.1481
Proportion with sacral trauma (n,%)3 (6.5%)8 (7.8%)1.0000
VAS SI joint pain score, mean (±SD)82.2 (9.9)82.3 (11.9)0.9280
ODI score, mean (±SD)61.1 (15.3)62.2 (14.5)0.6902
SF-36, mean (±SD)
 PCS
 MCS

30.8 (6.1)
43.3 (12.1)

30.2 (6.2)
43.0 (11.5)

0.5709
0.8624
EQ-5D
 TTO index
 Health Thermometer

0.47 (0.19)
57.8 (22.9)

0.44 (0.18)
53.2 (23.8)

0.3526
0.2716
  • * Fisher p-value for ordinal variables; t test for continuous variables.