Navigation-assisted reduction and fusion for 3 cases of high-grade pediatric dysplastic spondylolisthesis - A technical note

Background: High-grade dysplastic spondylolisthesis in the pediatric population presents significant anatomical and biomechanical challenges due to sacral doming, dysplastic pedicles, and altered spinopelvic parameters. There are high rates of non-union and instrumentation failure, especially without anterior column support. Intraoperative navigation improves accuracy in placing instrumentation and deformity correction. Methods: Three pediatric patients with high-grade dysplastic L5–S1 spondylolisthesis underwent reduction and circumferential spinopelvic fixation utilizing intraoperative 3D navigation. Key technical steps included insertion of convergent bi-cortical pedicle screws, sacral dome osteotomy, inter-body cage placement at L5–S1, and controlled reduction maneuvers. One patient’s fusion failed and warranted transcorporeal transdiscal screw fixation. Results: All 3 patients showed notable correction in deformity (i.e., a mean lumbosacral kyphosis reduction of 20° and slip angle correction of 13.3°). Sagittal balance improved from 6.3 cm to 3.3 cm anterior to the sacral promontory. Two of three patients achieved solid mono-block fusion, while one exhibited loss of reduction following a fall, requiring re-instrumentation and a transcorporeal transdiscal screw fixation. Conclusion: Intraoperative navigation facilitates accurate screw placement, safe reduction, and successful fusion for 3 pediatric patients with high-grade pediatric dysplastic spondylolisthesis.