[Minimally invasive arthrodesis of the sacroiliac joint (SIJ)].

Objective: Pain reduction and improvement in quality of life with sacroiliac joint (SIJ) fusion.

Indications: Chronic SIJ-associated pain; positive response to SIJ injection with local anesthetic; positive SIJ provocation tests; failed conservative therapy over 6 months.

Contraindications: Non-SIJ-associated pain; tumor/infection/unstable fracture in the implantation area; malformations; tumor or osteolysis of the sacrum or ilium bone; active infection at the implantation site; allergy to metal components; secondary gain from illness, request for a pension; inadequately treated osteoporosis.

Surgical Technique: Transarticular placement of Kirschner's wires through the SI joint via minimally invasive lateral approach. Guided preparation of implant site over Kirschner's wires and implantation of 3 triangular, transarticular titanium implants for SIJ fusion.

Postoperative Management: Deep vein thrombosis prophylaxis. 3 weeks partial weight-bearing and then moving on to full weight-bearing. X‑ray controls at defined intervals. Physiotherapy.

Results: We enrolled 26 patients who were followed up over the period of 4 years. The evaluated endpoints were low back pain on the visual analog scale (VAS 0-10), grade of disability with the Oswestry Disability Index (ODI) and quality of life with the EuroQOL-5D. At 4 years, mean low back pain improved compared to preoperative (VAS preoperative 8.4, VAS 4 years postoperative 4.6). Mean improvements in ODI (ODI preoperative 58.1, ODI 4 years postoperative 32.1) and EQ-5D (preoperative 0.5, after 4 years 0.7) could be evaluated over the long-term period of 4 years. Satisfaction rates were high and the proportion of subjects taking opioids decreased at the 4‑year follow-up (preoperative 82%, postoperative 39%). Implant loosening could not be detected on plain radiograph.