Twelve-month clinical and radiographic outcomes following inferior-posterior sacroiliac joint fusion using the catamaran SI joint fusion system: a prospective, multi-center evaluation.

Scientific evidence on novel transarticular inferior-posterior surgical approaches for sacroiliac (SI) joint fusion, designed to minimize the risk of neurovascular injury, remains limited. This prospective, multi-center study evaluated disability (ODI), SI-joint pain (VAS), and patient satisfaction following SI joint fusion using the inferior-posterior approach. The primary endpoint was composite success, defined as: (1) ≥20 mm VAS pain reduction, (2) no device-related serious adverse events, (3) no neurological worsening, and (4) no surgical reintervention. Fusion was assessed at 12 months via independent radiographic CT review. Thirty-six patients (mean age 58.9 years; 77.8% female) underwent treatment. At the time of analysis, ODI significantly improved from 51.6% at baseline to 28.0% at 6-month (n = 32) and 20.8% at 12-month (n = 24, all p < 0.001). VAS scores declined from 78.8 mm to 35.6 mm at 6-month (n = 30) and 23.0 mm at 12-month (n = 24, all p < 0.001). Composite success was achieved in 73.3% at 6 month and 87.0% at 12 months (post hoc). Fusion was confirmed in 82.6% of cases, with 83.3% patient satisfaction. No serious device- or procedure-related adverse events or reinterventions were reported. This interim analysis of an ongoing study demonstrates significant improvements in disability and pain, while the novel surgical approach promotes fusion. Although the results are promising, larger studies with longer follow-up are warranted to validate these findings.