. 2021 Jan 22;14(6):860–895. doi: 10.14444/7156

Table A2.

Published literature on minimally invasive surgical sacroiliac joint fusion. Inclusion criteria included the following: indexed in PubMed, English language, fusion of the sacroiliac joint described as minimally invasive surgery or percutaneous, and clinical outcomes available. Exclusion criteria included single-patient case reports, imaging studies, and technique reports with no clinical outcomes are excluded. The table also excludes Mao et al,¹⁸² as this article was simply an evaluation of the Oswestry Disability Index as an outcome measure, and the following 8 articles because they are narratives, systematic reviews, or meta-analyses: Shamrock et al,¹⁹¹ Whelan and Duhon,¹⁹⁰ Tran et al,¹⁸⁸ Zaidi et al,¹⁸⁹ Heiney et al,¹⁸⁶ Lingutla et al,¹⁸⁷ Yson et al,¹⁹² and Martin et al.¹⁹³

Author and Year	Study Design	N	Level of Evidence	Follow- Up, mo	Implant Type	Technique	BMP, DBM, Graft Used	Demographics	Results	Complications	Revisions
Dengler et al 2019¹⁵⁷	Prospective, multicenter, RCT (n = 52 iFuse, n = 51 CM) 2-y results	103	I	24	iFuse	Lateral	No	NSM (n = 51) Age: 46.7 y (23–69 y) Female: 37 (72.5%) 38 Pain duration: 4.5 y (0.45–23 y) BMI (kg/m²) 27.6 (16–44) SIJF (n = 52) Age: 49.4 y (27–70 y) 0.210 Female: 73.1% 0.999 Pain duration: 4.9 y (0.58–44 y) BMI 26.5 (18–42)	VAS improved by 45 points (37–54 points) after SIJF and 11 points (2–20 points) after CM, with a mean difference between groups of 34 points; ODI improved by 26 points (21–32 points) after SIJF and 8 points (2–14 points) after CM with a mean difference between groups of 18 points. EQ-5D at 6 mo (0.37 point) and 24 months (0.39 point) and smaller changes in the CM group at 6 mo (0.09 point) and 24 mo (0.15 point). The mean Zung Depression Scale score showed no improvement in the CM group and a 5.3-point improvement in SIJF group at 6 mo, and at 24 mo.	Within first 200 d, 20 AEs in the iFuse group and 17 AEs in the conservative group. No difference in rate between groups (p=0.664) By 24 months, 39 severe events in iFuse group 4 related to study device or procedure. In conservative group, 27 severe events 1 related to a study procedure.	3.8% (2 of 52 iFuse patients within 2 y)
Dengler et al 2017²²⁵	1-y, prospective, multicenter randomized controlled trial	103	I	12	iFuse	Lateral	No	NSM (n = 51) Age: 46.7 y (23–69) Female: 37 (72.5%) Pain duration: 4.5 y (0.45–23 y) BMI (kg/m²) 27.6 (16–44) SIJF (n = 52) Age: 49.4 y (27–70 y) Female: 73.1% Pain duration: 4.9 y (0.58–44 y) BMI 26.5 (18–42)	VAS improved by 41.6 points in the SIJF group vs. 14.0 points in the CM group. ODI in the SIJF group improved from 57.5 points at bsseline to 32.1 points at month 12. EQ-5D TTO improved from 0.35 to 0.74 EQ-5D VAS improved from 48.1 to 53.5 Zung Depression Scale improved from 45.7 to 39.6 at month 12	Two SIJF patients had recurrent pain attributed to possible device loosening and one had postoperative hematoma. In the CM group, 1 crossover patient had recurrent pain requiring a revision surgery.	1 revision
Sturesson et al 2017⁸⁵	Prospective, multicenter, RCT (n = 52 iFuse, n = 51 CM) 6-mo results	103	I	6	iFuse	Lateral	No	NSM (n = 51) Age: 46.7 y (23–69 y) Female: 37 (72.5%) 38 Pain duration: 4.5 y (0.45–23 y) BMI (kg/m²) 27.6 (16–44) SIJF (n = 52) Age: 49.4 y (27–70 y) 0.210 Female: 73.1% 0.999 Pain duration: 4.9 y (0.58–44 y) BMI 26.5 (18–42)	VAS: At 6 mo, mean LBP improved by 43.3 points in SIJF group and 5.7 points in the CM group (difference of 38.1 points). ODI improved by 26 points in the SIJF group and 6 points in CM group. EQ-5D changes of 0.15–0.46 reported	2 procedure-related AEs	0 revisions
Dengler et al 2017²²⁵	2-y, pooled patient- level analysis of 2 multicenter RCTs and 1 multicenter single- arm prospective trial	423	I	12	iFuse	Lateral	No	Mean (SD) age: 50.4 (11.2) y Female: 70.4% Pain duration: averaged 5.5 y (SD 6.7, table 2). Mean baseline SIJ pain: 80 points (SD 12.5) and ODI scores, 56 points (SD 12.7) were high. QOL was diminished (mean EQ-5D index TTO: 0.43, (SD 0.20) and mean SF-36 PCS: 31 (SD 5.9)	VAS 37.9 points larger in the SIJF group than in the NSM group. ODI 18.3 points larger. In NSM, no predictors of outcome. EQ-5D TTO index was 0.24 points larger for SIJF vs NSM.	Signs of wound infection occurred in 8 subjects overall, including deep wound infection requiring surgical washout (n = 1), drainage from wound treated with antibiotics (n = 3), redness treated with antibiotics (n = 3), and slow healing treated with antibiotics (n = 1)	Of the 326 patients undergoing SIJF, 1.2% (n = 4) underwent early surgical revision. Late revision surgery (>1 mo), performed in 2.8% (n = 9)
Polly et al 2016¹⁵⁶	Prospective, multicenter, RCT 2-y results	148: 102 iFuse, 46 NSM	I	24	iFuse	Lateral	No	Mean age: 51.3 y; 12.2% (n = 18) were 65 y or older. 95.3% Caucasian 103 (69.6%) female Subjects were highly debilitated by SIJ pain as indicated by high baseline pain ratings (mean 82.3 on the 0–100 scale) and ODI scores (mean 56.8).	VAS improvement of 55.4 points at month 24. 83.1% and 82.0% received either clinical improvement or substantial clinical benefit in VAS SIJ pain score. ODI: 68.2% and 65.9% received clinical improvement or substantial clinical benefit at month 24. EQ-5D = 0.28 at 24 mo SF-36 = 11.2 points at 24 mo	Within first 180 d: 1.5 per iFuse subject 1.3 per NSM subject	3% (3 of 102 iFuse patients within 2 y)
Polly et al 2015²²⁶	Prospective, multicenter, RCT 12-mo results	148: 102 iFuse, 46 NSM	I	12	iFuse	Lateral	No	Mean age: 51.3 y; 12.2% (18 subjects) were 65 years of age. 94.6% white 103 (69.6%) female Subjects were highly debilitated by SIJ pain, as indicated by high baseline pain ratings (mean, 82.3 on the 0–100 scale) and ODI scores (mean, 56.8)	VAS = 28.3 at the 12-mo follow-up (54.2-point improvement). ODI decreased from 57.2 at baseline to 28.1 at month 12 (improvement, 27.4 and 29.3 points, respectively. EQ-5D = improvement of 0.74 (0.20 points) SF-36 = 43.1 (10.3 points)	12 mo of follow-up, a total of 42 severe AEs occurred	1 revision
Whang et al 2015⁸⁴	Prospective, multicenter, RCT 6-mo results	148: 102 iFuse, 46 NSM	I	6	iFuse	Lateral	No	Mean age: 51 y and 18 (12.2%) were 65 y or older. 94.6% Caucasian Approximately two-thirds female. Subjects were highly debilitated by SIJ pain as indicated by high baseline pain ratings (mean 82.3 on the 0–100 scale) and ODI scores (mean 61.9).	6-mo follow-up was obtained in 97.3%. By 6 mo, success rates were 81.4% in the surgical group vs 23.9% in the NSM group. ODI improvement at 6 mo occurred in 75% of surgery subjects vs 27.3% of NSM subjects. At 6 mo, QOL improved more in the surgery group and satisfaction rates were high.	At 6-mo follow-up, 181 AEs were reported (133 in the surgery group and 48 in the NSM group). The mean number of events per subject was slightly higher in the surgery group (1.3 vs 1.0 events, P = .1857).	1 revision: implant-related impingement on a sacral nerve root requiring immediate revision
Whang et al 2019¹⁵⁹	Prospective, multicenter 5-y results	103	II	60	iFuse	Lateral	No	Mean age: 51 y; 97% Caucasian 73% female Subjects had high preoperative pain scores (mean [SD] of 81.5 [12.7]) and high levels of disability (ODI score 56.3 [12.1]). Duration of pain prior to enrollment averaged 5.7 y. EQ-5D at baseline was 0.45 (0.17), indicating a very poor QOL. 77% of subjects were taking opioids for back or SIJ pain preoperatively and 45% had a history of lumbar fusion, and concomitant spine and hip disease was common.	VAS pain scores at 5 y decreased by a mean of 54 points ODI decreased by 26 points EQOL-5D increased by 0.29 points	3 AEs were rated as device-related (1, intermittent hip and gluteal pain) and procedure-related (2, SI joint pain)	0
Darr and Cher 2018²²⁷	Prospective, multicenter 4-y results	103	II	48	iFuse	Lateral	No	NA	VAS pain scores in 91 subjects (88.3%) decreased by 54 points from baseline ODI decreased by 26 points EuroQOL-5D improved by 0.3 points	No new device- or procedure-related AEs during follow-up year 4	<1% (1 subject underwent revision at year 3.8)
Darr et al 2018²²⁸	Prospective, multicenter (n = 103) 3-y results	103	II	36	iFuse	Lateral	No	Mean (SD) preoperative SIJ pain score was 81.5 (12.6), and mean (SD) preoperative ODI was 56.3 (12.1)	At 3 y, VAS decreased to 26.2 (a 55-point improvement from baseline) and mean ODI was 28.2 (a 28-point improvement from baseline) EuroQol-5D (EQ-5D) improved by 0.30 points	No new device- or procedure-related AEs during follow-up year 3	<1%
Patel et al 2020¹⁶⁰	Prospective, multicenter	51	II	12	iFuse	Lateral	No	Mean (SD) age: 53.2 y Female: 39 (76.5%) Mean (SD) BMI: 31.3 (7.6) Nonwhite race: 3 (5.9%) Hispanic: 2 (3.9%) ODI: 56.3	ODI decreased from 52.8 at baseline to 27.9 at 12 months. VAS pain scores improved from 78 preoperatively to 21 at 12-mo follow-up 96% experienced an improvement of 20 points or more in VAS SIJ pain by month 12 EuroQOL-5D improved from 0.47 at baseline to 0.74 at month 12	112 AEs were reported in 43 subjects. Of these, 1 was related to the device.	1 revision due to implant malposition and 1 revision after a vehicle accident. Revision rates consistent with those observed in postmarket surveillance for iFuse-3D.
Patel et al 2019²²⁹	Prospective, multicenter	28	II	6	iFuse	Lateral	No	Mean age: 52 y (SD 15) Female: 23 (82%) Mean BMI: 30.7 (SD 5.0) Nonwhite race: 1 (3.6%) Hispanic: 2 (7.1%)	VAS decreased by 51 points and ODI decreased by 23.6 points	NA	NA
Duhon et al 2016¹⁵⁸	Prospective, multicenter, single-arm, clinical trial 2-y results	172	II	24	iFuse	Lateral	No	Average age: 50.9 y 96.5% Caucasian 69.8% femal Baseline SIJ pain (mean 79.8 points, 0–100 scale) ODI, mean 55.2 Average pain for 5.1 y (0.43–41.08 y). QOL was substantially diminished (mean EQ-5D TTO of 0.43 and mean SF-36 PCS of 31.7)	VAS decreased from 79.8 at baseline to 26.0 at 24 mo ODI decreased from 55.2 at baseline to 30.9 at 24 mo	2.9% probably or definitely device-related 12.2% probably or definitely procedure-related	4.7% (8 of 172 patients)
Duhon et al 2016²³⁰	Prospective, multicenter, single-arm, clinical trial 1-y results	172	II	12	iFuse	Lateral	No	Mean age: 50.9 y 96.5% Caucasian 69.8% female Baseline pain ratings (mean 79.8) and (ODI mean 55.2). Mean pain duration 5.1 y (0.43–41 y); 84.3% had pain for >1 y and 64.5% had pain for >2 y.	VAS improved from 79.8 at baseline to 30.0 and 30.4 at 6 and 12 mo, respectively (mean improvements of 49.9 and 49.1 points) Mean ODI improved from 55.2 at baseline to 32.5 and 31.4 at 6 and 12 mo (improvements of 22.7 and 23.9 points) SF-36 PCS improved from 31.7 at baseline to 40.2 and 40.3 at 6 and 12 mo Mean EQ-5D TTO index improved from 0.43 at baseline to 0.69 at 6 mo and 0.71 at 12 mo, increases of 0.25 and 0.27 points, respectively	5 AEs related to device: 2 Neuropathy related to malposition: 1 SIJ pain after fall associated with inadequate device placement: 1 Hip pain related to periosteal bone: growth around implant, 1 Mild buttock pain. 21 AEs related to procedure: 5 wound infection or drainage: 5 Buttocks or SIJ pain: 3 Postoperative nausea/vomiting: 2 Neuropathy related to malposition: 1 Staple irritation: 1 Numbness around Surgical wound: 1 Gluteal artery bleeding: 1 Urinary retention: 1 Fall causing SIJ pain:	4 cases (2.3%).
Duhon et al 2013²³¹	Prospective, multicenter, single-arm, clinical trial 6-mo results	94	II	6	iFuse	Lateral	No	Mean age: 51 y (n = 94, safety cohort) 66% female Subjects were highly debilitated at baseline (mean VAS pain score 78, mean ODI score 54).	VAS improved from a baseline score of 76 (±16.2) to a 6-mo score of 29.3 (±23.3, an improvement of 49 points) ODI improved from 55.3 (±10.7) to 38.9 (±18.5, an improvement of 15.8 points) SF-36 PCS improved from 30.7 (±4.3) to 37.0 (±10.7, an improvement of 6.7 points) EQ-5D TTO index improved from 43 at baseline to 65 at follow-up, a 23-point improvement. EQ-5D improved from 54 to 65 (an increase of 10 points)	53 AEs occurred in 34 subjects	0 revisions
Capobianco et al 2015²³²	Prospective, multicenter trial 12-mo results	172	II	12	iFuse	Lateral	No	52 males, 100 females without PPGP and 20 females had PPGP. PPGP subjects were significantly younger (43.3 y, vs. 52.8 y for females without PPGP and 50.5 y for men.	Averaged VAS across 3 groups: 29.7 (31.4, 32.7, 25.0) Averaged ODI across 3 groups: 31.8 (32.8,30.8, 31.9). Women with PPGP experienced a significant improvement in pain (51 mm on VAS), function (20.6 points on ODI) and QOL (SF-36 PCS +10.4, MCS +7.2, EQ-5D +0.31) at 12 mo	283 AEs occurred between enrollment and the 12-mo visit: 37 in women with PPGP, 158 in women without PPGP and 88 in men	Revision rate was 5% in PPGP subjects, 2% in women without PPGP, and 1.9% in men. The revision rate for all subjects in SIFI was 2.3% (4/172)
Cross et al 2018¹⁸⁴	Prospective multicenter	19	II	24	Threaded implant	Lateral	Autograft used	Mean age: 60.1 y 15 female BMI: 29.1	VAS reduced to 2.2/10 12 mo postoperatively and 2.1/10 24 mo postoperatively 72% and 73% reduction in LBP, respectively. Reduction in LBP at both 12 and 24 mo, with large effect sizes of −3.5 and −2.9, respectively. At 12 months, 19/19 (100%) of patients met the MCID of ≥2/10 improvement on the NPS; at 24 mo follow-up 17/18 (94%) met the MCID.	No procedural complications, nor any device or procedure-related serious AEs	0 revisions
Kube and Muir 2016¹⁸⁵	Prospective	18	II	12	Threaded implant	Lateral	Autograft used	Mean age: 47.2 y (SD 14.2) Mean BMI: 29.4 (SD 5.3), 56% female	VAS back pain improved from 81.7 to 44.1 points and VAS leg pain from 63.6 to 27.7 points. ODI improved from 61.0 to 40.5 (P = .009).	4 procedural complications.	0 revisions
Rappoport et al 2017¹⁶²	Prospective	32	II	12	Hydroxyapatite- coated screw	Lateral	Autograft used	Mean age: 55.2 y 62.5% female	VAS decreased from 55.8 mm preoperatively to 28.5 mm, 31.6 mm, and 32.7 mm, respectively, at 3, 6, and 12 mo postoperatively Mean ODI scores decreased from 55.6 to 33.3, 33.0, and 34.6, respectively, at 3, 6, and 12 mo postoperatively	No procedural complications	2 revisions
Araghi et al 2017¹⁶¹	Prospective multicenter	50	II	6	Threaded implant	Lateral	Autograft used	Average age at baseline: 61.5 y 58% female	VAS pain reduction at 6 mo from 76.2 at baseline to 35.1 Mean ODI improved from 55.5 to 35.3 at 6 mo	2 serious AEs reported for 2 patients	1 revision (2%)
Vanaclocha et al 2018¹⁶⁵	Comparative case series with 6-y follow-up	137: 63 CM, 47 SI denervation, 27 SIJF	III	72	iFuse	Lateral	No	SIJF group (n = 27): Mean age: 48 y Female: 19 BMI: 29.5	SIJF group: VAS mean pain 6 mo, 2.2; 12 mo, 1.9; 24 mo, 1.8; 36 mo, 1.8; 48 mo, 1.9; 60 mo, 2.0; 72 mo, 2.0 ODI: 6 mo, 26; 12 mo, 20; 24 mo, 19; 36 mo, 18; 48 mo, 17; 60 mo, 20; 72 mo, 22	No SAEs or procedural complications	0 revisions
Ledonio et al 2014¹¹⁹	Retrospecive study	44: 22 open, 22 MIS	III	12	iFuse	Lateral	Autograft used	MIS group only (n = 22): Average age: 47.9 y, BMI: 30.5, 17 female	MIS group only: preop ODI, 61.5; postop ODI, 52.0.	MIS group only: 3 complications	MIS group: 2 revisions
Claus et al 2020¹⁶⁶	Retrospective review: comparison of patient-reported outcomes	156: 74 with CTIs, 82 with TDIs	III	12	Cylindrical threaded implants and iFuse	Contralateral posterior superior iliac spine; iFuse: lateral	Allograft used	Average age: 58.4 y, (23– 82 y) 54 female (73%) Triangular dowel implant cohort: 82 patients; 73.2% female (60 patients) Average age: 55.7 y (27–85 y)	Average both MIS VAS and ODI scores for Rialto and iFuse. VAS: −2.8, −2.4 = −2.6 subtract from baseline 8.0 = 5.4 ODI: −8.3, −6.2 = −7.25, baseline 54.65 = 47.4 Rialto (n=74): VAS back −2.8(3.3), VAS leg −1.7 (4.4), ODI −8.3 (14.9), SF-12 2.5 (5.7) iFuse: (n = 82) VAS back −2.4 (4.9), VAS leg −1.9 (4.6), ODI −6.2 (13.3), SF-12 −0.5 (9.9)	Complication rates have been seen as high as 16% in the iFuse system and as high as 52% in the CTI system.	6.1% revision rate in the CTI cohort was observed compared to a 2.4% revision rate in iFuse
Rudolf 2012¹⁷⁶	Retrospective review: comparison of patient-reported outcomes	50	IV	24	iFuse	Lateral	No	Average age: 54 y (24–85 y), 34 female (68%), 16 male (32%), prior lumbar fusion 22 (44%)	NRS 1–10 reported pain measures. Reported in reductions from baseline. QOL measures, but not ODI. Pain scores improved by an average of 5.9 points (n = 45)	10 peri-operative complications.	8% at 3 y
Ledonio et al 2014¹²⁰	Comparative retrospective chart review	39: 22 open fusion, 17 MIS	IV	12	3-hole reconstruction plate vs iFuse	Open anterior vs MIS l ateral	Autograft on open SIJ surgery, not in MIS SIJF.	39 patients (22 open, median age 66: 17 MIS, median age 51) who underwent SIJF with minimum 1-y follow-up	ODI scores improved significantly, from a median of 64 (44–78) to a median of 46 (10–80) in the open group and from a median of 53 (14–84) to a median of 13 (0–30) in the MIS group
Sachs and Capobianco 2012²³³	Retrospective study	11	IV	12	iFuse	Lateral	Autograft used	Age: 65 y (45–82); 10 female (91%), 1 male (9%); prior lumbar spine surgery 3 (27%)	NRS 1–10 mean baseline pain score (SD) was 7.9 (± 2.2). Mean pain score at the 12-mo follow-up interval was 2.3 (±3.1). Mean (SD) change in pain score was 5.4 (3.4) points
Bornemann et al 2017¹⁷⁹	Retrospective 2-y	24	IV	24	iFuse	Lateral	No	Mean age: 54.9 y (18–76 y) Male: 2; female: 22	VAS scores and ODI improved significantly directly after surgery from 84.3 ± 9.2 mm to 40.7 ± 9.2 mm and 19 from 76.8 ± 9.2% to 40.7 ± 9.2%. ODI improved further to 31 ± 5.4% after 24 mo, VAS 20 improved until the 3-mo examination and then stayed constant between 27.7 mm and 26.5 mm to 27 ± 6.6 mm at 24 mo	None	0 revisions
Bornemann et al 2016²³⁴	Retrospective 1-y	24	IV	12	iFuse	Lateral	No	Mean age: 54.9 y (18–76 y) Male: 2; female: 22	VAS 58 ± 11 mm (68% ± 7%) ODI median decrease of 44 percentage points 57%	None	0 revisions
Rudolf 2013²³⁵	Retrospective review	40	IV	24	iFuse	Lateral	No	Mean age: 54 y NF: 18 (12 female, 6 male) PF: 11 female. 4 male LP: 7 (3 female, 4 male)	NRS scale mean change from baseline: NF cohort (n = 18) −5.94 (3.30), PF cohort (n = 15) −5.81 (3.50), LP cohort (n = 7) −4.79 (4.28)	8 peri-operative complications in 7 patients (17.5% complication rate; 3 from the NF cohort and 5 from the PF cohort) that all resolved without clinical sequelae	1 revision
Al-Khayer et al 2008¹⁵⁰	Retrospective, single center	9	IV	24	Hollow modular anchor, hollow screw	Lateral	autograft	Average age: 42.4 y (35–56 y). Mean duration of symptoms before surgery: 30 mo (12–84 mo)	VAS dropped from 8.1 (7–9) preoperatively to 4.6 (3–7) postoperatively Mean ODI dropped from 59 (34–70) preoperatively to 45 (28–60) postoperatively (P<0.005).	1 complication observed; a deep wound infection, which healed with debridement and intravenous antibiotics.	0 revisions
Sachs et al 2014¹⁷²	Retrospective	144	IV	12	iFuse	Lateral	No	Mean age: 58 y 71% female 62% had a history of lumbar spinal fusion	VAS pain scores from 8.6 improved by 6.1 points (5.7–6.6) to 2.7 points. Substantial clinical benefit, defined as a decrease in pain by 2.5 points or a score of 3.5 or less, was achieved in 91.9% of patients	28 reported AEs, no intraoperative complications	2 revisions
Sachs 2013¹¹⁸	Retrospective	40	IV	12	iFuse	Lateral	No	Mean age: 58 y (30–81 y) 30 female, 10 male	VAS improved from 8.7 (1.5 SD) at baseline to 0.9 (1.6) at 12 mo, a 7.8-point improvement	No intraoperative complications. 2 patients presented with trochanteric bursitis, 1 incident of piriformis syndrome 1 episode of new LBP	0 revisions
Sachs et al 2016¹⁷¹	Retrospective, multicenter 3.7-y follow-up	107	IV	44	iFuse	Lateral	No	Mean age: 57.5 y (18–87 y) Mean BMI: 29.8 Years with SIJ pain: 5.9 y white 90.7%, black 5.6%, Hispanic 3.7%	Baseline to follow-up ODI 7.5 (1.7) to 2.6 (2.7), change score mean −4.8 (2.9) Follow-up ODI score mean 28.2 (21.3)	3 (2.8%) procedure-related complications	4.7% (5 of 107 patients)
Cummings and Capobianco 2013¹⁷³	Retrospective chart review	18	IV	12	iFuse	Lateral	No	Mean age: 64 y (39–81 y) Primarily white (83%) and female (67%). 89% of patients in cohort were obese (BMI > 30) or overweight (BMI 25–30), and 44 hypertensive. 83% had history of previous lumbar spine surgery that included fusion at 1 or more levels (73%), decompression (13%), and discectomy (13%)	VAS baseline mean 8.9 (SD 1.9), 12 mo 2.3 (SD 2.1). ODI baseline mean 52.7, 12 mo 13.2 (SD 12.6) SF-12 PCS 32.3 (SD 6.4), 12 mo 44.6 (SD 10.5). SF-12 MCS 37.6 (SD 10.2), 12 mo 53.8 (SD 9.5)	No intraoperative complications, 5% complication rate.	0 revisions
Gaetani et al 2013¹⁷⁵	Retrospective chart review	12	IV	12	iFuse	Lateral	No	Mean age: 53.2 y (36–71 y).	Mean (±SD) ODI 31.4 (±6.3) preoperatively and 12 (±3.5) postoperatively QOL improved by 14.6 points from a baseline mean of 17.6 (±1) to 3 (±4.1) at follow-up. Mean preoperative VAS 7.7 (±1.3) and at follow-up improved by an average of 4.7 points for a mean follow-up score of 3 (±1.2)	NA	NA
Schroeder et al 2014¹⁷⁴	Retrospective review	6	IV	10.25	iFuse	Lateral	No	Average age: 50 y (25–60 y). The patients were 15.3 y on average after the original surgical procedure (range 4–25 y).	VAS score improved from 6.5 to 2.0; MCID 1.6 Back VAS score decreased from 7.83 to 2.67 mm. ODI scores dropped from 22.2 to 10.5. SRS22 scores increased from 2.93 to 3.65	No complications	0 revisions
Cleveland et al 2019¹⁸¹	Retrospective review	50	IV	12	iFuse	Lateral	Mix of BMP, DBM, and autograft used	Average age: 51 y 12 males, 38 females Average BMI: 29.2	VAS preop (n= 57) 6.2, postop 12 mo (n = 39) 3.9, 13–22 mo (n = 13) 2.8 ODI preop (n = 32) 49.2, 12 mo (n = 13) 24.6, 13–22 mo (n = 17) 20.8 DSIJQ preop (n = 20) 53.2, 12 mo (n = 10) 17.4, 13–22 mo (n=16) 20.8	22% complication rate	4 revisions
Rudolf and Capobianco 2014¹⁷⁸	Prospective	17	IV	60	iFuse	Lateral	No	Mean age: 58 y (36–85 y) 77% female 47% had prior lumbar spinal fusion	VAS improved from 8.3 at baseline to 2.4 at 5 y 88% of patients reached substantial clinical benefit ODI 5 y: 21.5	No evidence of long-term complications, implant migration or loosening	0 revisions
Khurana et al 2009¹⁵²	Retrospective	15	IV	17	Hollow modular anchor hollow screw		No	Mean age: 48.7 y (37.3–62.6 y)	Mean SF-36 scores improved from 37 (23–51) to 80 (67–92) for physical function and from 53 (34–73) to 86 (70–98) for general health Mean Majeed score improved from 37 (18–54) preoperatively to 79 (63–96) postoperatively	No postoperative neurological or wound complications	0 revisions
Smith et al 2013¹¹⁷	Retrospective multicenter	263: 149 open, 114 MIS SIJF	IV	24	MIS only: iFuse	Lateral	No graft used for TTIs	MIS group only (n = 114): Mean age: 57.4 y 82 female 54 with prior lumbar fusion	MIS group only (n = 114): VAS baseline 8.3, VAS 12 mo 2.3, 24 mo 1.7	No intraoperative complications occurred	Revisions (3.5%) in the MIS group were the result of suboptimal implant placement.
Kancherla et al 2017¹⁶⁹	Retrospective analysis	45: 36 iFuse, 9 SAMBA screw	IV	32	iFuse	Lateral	No	Average age: 52.7 y BMI 28.6 14 female	VAS 4.0 ODI 35.2 SF-12 PCS 40.2 SF-12 MCS 45.4	3 complications	1 SAMBA screw revision, 1 iFuse revision
Rainov et al 2019¹⁸⁰	Retrospective case series	160	IV	12	iFuse	Lateral	No	Mean age: 58 y 68% female	VAS pain decreased from 8.0 to 2.5 ODI decreased from 45.3 to 16.4 Follow-up was obtained in 151 patients at 3 mo, 135 patients at 6 mo, 114 at 9 mo, and 90 at 12 mo Mean (±SD) VAS of SIJ pain improved from 8.0 (±0.8) at baseline to 3.5 (±1.6) at 6 mo and 2.5 (±1.4) at 12 mo Mean (±SD) ODI improved from 45.3 (±2.3) at baseline to 22.1 (±8.8) at 6 mo and 16.4 (±6.6) at 12 mo At follow-up 12 months, 97% had a VAS improvement from baseline of at least 2 points, 97% had ODI improvement of at least 15 points, 66% had a VAS level of 2 or less, and 56% had an ODI level of 15 or less	No intraoperative complications	0 revisions
Rajpal and Burneikiene 2019¹⁶⁸	Retrospective review	24	Review article	19	Cylindrical threaded implants	Lateral	Allograft	Average age: 62.2 y 3 males, 21 females	VAS reduction from an average baseline score of 6.6 to 3.7 postoperatively. Leg pain scores decreased from 4.8 to 1.5	2 patients had symptomatic subcutaneous hematomas, which resolved spontaneously, and 2 patients had superficial wound infections treated with antibiotics.	0 revisions
Dorsal/Posterior
Endres and Ludwig 2013²²¹	Prospective	19	II	13.2	Threaded fusion cage^a	Posterior	Autograft	Mean age: 60.9 y (36–76 y)	VAS: 8.5 before surgery and 6 at final follow-up Mean ODI: 64.1 before surgery and 56.97 at final follow-up	No intraoperative complications.	0 revisions
Fuchs and Ruhl 2018²²²	Prospective	171	II	24	Threaded fusion cage^a	Posterior	Allograft		At 24 mo: MVAS improved from 63% to 36%, ODI from 51% to 33%, SF-MPQ from 50% to 31%, VAS from 74 to 37. Radiographic fusion rate 19% without BMP, 67% with BMP.	1 complication L5 radiculitis. 33% of cases had poor implant position (implant too far into sacrum or ilium)	1 revision
McGuire et al 2012¹¹²	Retrospective case series	37	IV	40	Fibular dowel allograft^a	Posterior	Allograft	Mean age: 42.5 y (23–63) 34 females, 3 males	VAS score: 3.4 (94% achieved clinical important difference at 6 mo and maintained through follow-up) Fusion achieved: 34 (89.5%); nonunion: 4 (10.5%)	Nonunion occurred at 4 sites (10.5%). Each SIJ nonunion was successfully treated by secondary autogenous bone grafting and iliosacral compression screw fixation. There were no infections.	NA
Wise and Dall 2008²²⁰	Prospective	13	II	12	Threaded fusion cage^a	Posterior	No	Average age: 53.1 y (45–62 y) 12 females, 1 male	VAS back pain improved an average of 4.9 VAS leg pain improved an average of 2.4 Dyspareunia improved by an average of 2.6	No infections or neurovascular complications.	0 revisions

Abbreviations: AE, adverse event; BMP, bone morphogenetic protein; CM, conservative management; CTI, Cylindrical Threaded Implant; DBM, Demineralized Bone Matrix; DSIJQ; Denver Sacroiliac Joint Questionnaire, EQ-5D, Euroquol 5 dimension quality of life measure; LBP, low back pain; LP: patients with concomitant lumbar pathology treated non surgically; MCID, minimal clinically important difference; MIS indicates minimally invasive surgical; MVAS indicates Million Visual Analog Scale; SF-MPQ indicates Short Form McGill Pain Questionnaire; NF, patients with no history of spinal fusion or confounding lumbar pathology; ODI, Oswestry Disability Index; PCS, physical component summary; PF, patients with history of prior lumbar spinal fusion; PPGP, posterior pelvic girdle pain; QOL, quality of life; RCT, randomized controlled trial; SIJ, sacroiliac joint; SIJF, sacroiliac joint fusion; TDI, Triangular Dowel Implant; TTO, time trade-off index; VAS, visual analog score.

Not FDA cleared for SIJF.