Table 1.
Characteristics of effectiveness and safety cohorts
| Effectiveness cohort (n=32) | Safety cohort (n=94) | P-value* | ||||
|---|---|---|---|---|---|---|
| Age, mean (±SD) | 50.2 (12.6) | 51.2 (10.8) | 0.5128 | |||
| Sex (n, % female) | 21 (66%) | 62 (66%) | 0.9610 | |||
| White race (n, %) | 32 (100%) | 89 (95%) | 0.4359 | |||
| Hispanic or Latino (n, %) | 0 (0%) | 3 (3.2%) | 0.2060 | |||
| Body mass index, mean (±SD) | 31.4 (7.3) | 29.8 (7.2) | 0.1026 | |||
| Current smoker (n, %) | 11 (34%) | 30 (32%) | 0.6847 | |||
| Ambulatory without assistance (n, %) | 29 (91%) | 87 (93%) | 0.6089 | |||
| Work status (n, %) | ||||||
| Working full time | 10 (31%) | 32 (34%) | 0.6097 | |||
| Not working due to SI joint pain | 14 (44%) | 36 (38%) | ||||
| Prior lumbar fusion (n, %) | 22 (69%) | 58 (62%) | 0.5435 | |||
| Months of pain, mean (±SD) | 53.6 (94.3) | 60.8 (84.2) | 0.5547 | |||
| Pain syndrome | ||||||
| Pain began peripartum | 6 (19%) | 12 (13%) | 0.2928 | |||
| Pain radiates down leg | 31 (97%) | 79 (84%) | 0.0198 | |||
| Groin pain | 20 (63%) | 55 (59%) | 0.6330 | |||
| Pain worse with sitting | 28 (88%) | 83 (88%) | 0.6936 | |||
| Pain worse with rising | 25 (78%) | 72 (77%) | 0.9062 | |||
| Pain worse with walking | 28 (88%) | 80 (85%) | 0.7658 | |||
| Pain worse with climbing stairs | 28 (88%) | 82 (87%) | 0.8844 | |||
| Pain worse descending stairs | 19 (59%) | 65 (69%) | 0.1093 | |||
| Prior treatments | ||||||
| Physical therapy | 23 (72%) | 60 (64%) | 0.2827 | |||
| Steroid SI joint injection | 32 (100%) | 89 (95%) | 0.1387 | |||
| RF ablation | 3 (9%) | 10 (11%) | 0.7561 | |||
| Taking narcotics (n, %) | 24 (75%) | 74 (79%) | 0.5263 | |||
| Proportion with lumbar stenosis (n, %) | 10 (31%) | 23 (25%) | 0.4896 | |||
| Proportion with hip diagnosis (n, %) | 3 (9%) | 11 (12%) | 0.6141 | |||
| Left | Right | Left | Right | Left | Right | |
|
| ||||||
| Physical exam findings | ||||||
| FABER/Patrick’s | 17 (94%) | 13 (93%) | 38 (90%) | 45 (88%) | 0.2401 | 0.8457 |
| Compression | 16 (89%) | 11 (79%) | 34 (81%) | 40 (78%) | 0.6525 | 0.9329 |
| Thigh thrust | 14 (78%) | 14 (100%) | 31 (74%) | 44 (86%) | 0.6691 | 0.3810 |
| Distraction | 11 (61%) | 8 (57%) | 27 (64%) | 28 (55%) | 0.7368 | 0.9265 |
| Gaenslen | 9 (50%) | 7 (50%) | 22 (52%) | 31 (61%) | 0.5066 | 0.5787 |
| VAS pain score, mean (±SD) | 76.2 (16.2) | 77.8 (13.9) | 0.4008 | |||
| ODI score, mean (±SD) | 55.3 (10.7) | 54.0 (11.0) | 0.7219 | |||
| SF-36, mean (±SD) | ||||||
| PCS | 30.7 (5.3) | 31.8 (5.8) | 0.1854 | |||
| MCS | 41.0 (9.6) | 40.0 (11.1) | 0.5318 | |||
| EQ-5D | ||||||
| TTO index | 43.0 (16.7) | 45.2 (17.9) | 0.3956 | |||
| Health thermometer | 53.8 (21.3) | 55.7 (22.8) | 0.5697 | |||
Note:
*
P-values compare effectiveness cohort versus those enrolled but not in the effectiveness cohort.
Abbreviations: EQ-5D, EuroQoL-5D; FABER, Flexion, ABduction, External Rotation, and Extension; MCS, mental component summary; ODI, Oswestry Disability index; PCS, physical component summary; RF, radiofrequency; SD, standard deviation; SI, sacroiliac; SF-36, short Form-36; SI, sacroiliac; TTO, time trade-off; VAS, visual analog scale.