This section describes safety outcomes from the published literature that the committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the interventional procedure overview.
5.1 The overall complication rate was 4% (204/5,319) in a prospective database analysis of post-marketing complaints for patients having minimally invasive sacroiliac (SI) joint fusion for degenerative sacroiliitis and SI joint disruption. Pain was the most commonly reported event (2% [119/5,319]), followed by nerve impingement in less than 1% (n=48) and recurrent SI joint pain in less than 1% (n=43).
5.2 The overall complication rate was 13% (57/432) in a systematic review and meta-analysis of 432 patients from 12 cohort studies on minimally invasive SI joint fusion using a lateral transarticular approach. The most common events were surgical wound problems (4%, 17/432), trochanteric bursitis (2%, 8/432), facet pain (less than 1%, 3/432), recurrent SI pain (less than 1%, 3/432), toe and foot numbness (less than 1%, 2/432), and nerve root impingement needing revision in 2% (9/432) patients. In a systematic review on SI joint fusion including 430 patients, for those having minimally invasive SI joint fusion (n=299 in 9 studies), complications reported were new-onset facet joint pain, trochanteric bursitis, deep wound infections, new onset of low back or buttock pain, worsening knee or leg pain, superficial cellulitis, radiculopathy, large haematomas, vascular necrosis of the hip, piriformis syndrome, implant penetration into the sacral neural foramen, peripheral neuropathy, a non-displaced fracture, pulmonary embolism and deep vein thrombosis.
5.3 The device-related adverse event rate was 1% (75/5,319) in the prospective database analysis of post-marketing complaints. These were related to issues with binding, bending or breakage of the Steinmann pin (n=43), pin advancement difficulties (n=14), radiographic halo (n=13) and device migration (n=4). In a randomised controlled trial (RCT) of 148 patients, device-related events were reported in 3% (3/102) in the SI joint fusion group at 6‑month follow-up. Two events (1 implant-related impingement on a sacral nerve causing pain and needing immediate revision and 1 hairline ilium fracture adjacent to implant causing pain resolved after revision surgery) were definitely related to the device and 1 event (SI joint pain because of suboptimal placement of implants, which needed revision surgery) was deemed probably related to the device.
5.4 The procedure-related adverse event rate was 2% (108/5,319) in the prospective database analysis of post-marketing complaints. Improper implant placement was reported in 1% (n=72) of patients. Improper device length was reported in less than 1% (n=36) of patients, with most implants deemed to be too short (n=30). In the RCT of 148 patients, 19% (19/102) of the events were probably or definitely related to the SI joint fusion and 11% (5/46) of the events were related to non-surgical management (NSM) at 6‑month follow-up. Events related to surgical procedure included neuropathic symptoms (n=1), postoperative medical problems (n=4; urinary retention, nausea/vomiting, atrial fibrillation), SI joint pain or trochanteric bursitis (n=7), surgical wound problems (n=5), iliac fracture (n=1) and asymptomatic physical examination findings (n=1). With NSM, 3 patients reported SI joint pain after treatment; 1 had flushing and shortness of breath after SI joint injection and 1 had worsening SI joint pain related to physiotherapy.
5.5 The revision rate was 2% (9/432) in the systematic review and meta-analysis of 432 patients. Reoperation rate ranged from 0% to 17% (mean 6%) in the 299 patients who had minimally invasive SI joint fusion surgery in the systematic review of 430 patients (in 9 studies; mean follow-up of 21 months). In the prospective database analysis of post-marketing complaints, the reoperation rate was 2% (n=96/5,319) at a median follow-up of 4 months. Revisions were typically done in the early postoperative period (median 19 days) for treatment of a symptomatic wrongly positioned implant (less than 1%, n=46), or to correct an improperly sized implant in an asymptomatic patient (less than 1%, n=10). Revisions in the late postoperative period were done (at a median of 297 days) to treat symptom recurrence (n=34) or for continued pain of undetermined aetiology (n=6). Revision outcomes and management in these patients were not reported.
5.6 Postoperative infection rate was 4% (n=19) at 6 months in a retrospective analysis of 469 patients treated by minimally invasive SI joint fusion.
5.7 In addition to safety outcomes reported in the literature, specialist advisers are asked about anecdotal adverse events (events which they have heard about) and about theoretical adverse events (events which they think might possibly occur, even if they have never done so). For this procedure, specialist advisers listed the following anecdotal adverse events: non-union and implant loosening, which would be similar to pseudoarthrosis. They considered that the following were theoretical adverse events: residual pain and injury to L5 or sacral nerve roots by wrong positioning of the screw (implant).
5.8 Eight commentaries from patients who had experience of this procedure were received, which were discussed by the committee.