Five-Year Clinical and Radiographic Outcomes After Minimally Invasive Sacroiliac Joint Fusion Using Triangular Implants

OBJECT : Previous reports of minimally invasive (MIS) sacroiliac (SI) joint fusion for low back, SI joint, and buttock pain secondary to SI joint disorders have shown favorable short- and mid-term outcomes. Herein we present 5-year clinical and radiographic outcomes after MIS SI joint fusion using a series of triangular porous titanium plasma spray (TPS) coated implants. METHODS : Consecutive patients treated with MIS SI joint fusion for degenerative sacroiliitis and/or sacroiliac joint disruptions between October 2007 and March 2009 were evaluated. Pain on VAS, an SI joint specific survey and Oswestry Disability Index (ODI) were administered. X-ray and CT scans were obtained to assess the implants. RESULTS : Of 21 patients treated, 17 were available for the study. Mean age was 58 years (range 36-85), 77% were female and 47% had prior lumbar spinal fusion. Pain on VAS improved from 8.3 at baseline to 2.4 at 5 years; 88% of patients reached Substantial Clinical Benefit. Mean ODI score at 5 years was 21.5 (SD 22.7). Patient satisfaction achieved at 12 months was maintained for 5 years (82%). A qualitative review of x-ray and CT imaging showed increased bone density immediately adjacent to all implants, intra-articular osseous bridging in 87% of patients and no evidence of implant loosening or migration. CONCLUSION : Long-term clinical and radiographic outcomes after MIS SIJ fusion are favorable. Clinical improvements observed at 12 months postoperatively were maintained at 5 years. There was no evidence of long-term complications, implant loosening or migration. Patients who did not achieve large improvements were affected by multiple severe concomitant degenerative conditions of the lumbar spine, pelvis, and/or hip.