Bone resorption by osteoclasts.

BACKGROUND

Bilateral sacroiliac joint fusion (BSIJF) is an accepted management strategy for sacroiliac joint dysfunction, though outcomes data are limited by patient number and lack of long-term follow-up. This study investigated the clinical, radiological, and patient-reported outcomes of BSIJF.

METHODS

A retrospective review was conducted of all patients who underwent BSIJF with a single surgeon between 2020 and 2023. All BSIJF utilized a principles-based approach: joint decortication, bone grafting, compression, and rigid stability. Patient-reported outcomes at preoperative, 6-month, 1-year, and 2-year follow-up timepoints were recorded for the Numeric Pain Rating Scale, Oswestry Disability Index (ODI), Single Assessment Numeric Evaluation (SANE), PROMIS Pain Interference (PI), and PROMIS Physical Function (PF). Fusion grading was assessed by computed tomography after 1 and 2 years.

RESULTS

Forty-eight patients who underwent BSIJF were included, of whom 31 (65%) were women with a mean age of 54 ± 14 years and a mean body mass index of 29 ± 5. Twenty-five patients (52%) had prior lumbar spine surgery (PLSS). One patient required revision for implant malpositioning and nerve impingement. Bridging bone across the sacroiliac joint was observed in 85% of patients. Numeric Pain Rating Scale scores dropped significantly from 7.6 preoperatively to 3.9, 3.3, and 3.7 at 6-month, 1-year, and 2-year follow-ups, respectively (P ≤ 0.004). PI and PF scores were significantly improved at all timepoints (all P < 0.001). ODI scores demonstrated sustained improvement from 52.3 preoperatively to 33.3 at 1-year follow-up and 29.3 at 2-year follow-up (P < 0.001). SANE scores were 80% at 1-year follow-up and 85% at 2-year follow-up. PI, PF, and ODI scores were significantly improved at all timepoints, independent of PLSS status. The mean SANE score in patients with PLSS was 82% ± 22% at 2-year follow-up. Patient history of hip surgery prior to BSIJF was associated with inferior postoperative ODI and SANE scores.

CONCLUSIONS

BSIJF is a safe and effective treatment that is associated with high rates of bony bridging at the sacroiliac joint and long-term clinically significant improvements in pain and function.