Technical aspects of performing a hemivertebrectomy for adolescent congenital scoliosis: Illustrative case.

backgroundHemivertebrae (HVs) are congenital spinal anomalies that disrupt normal vertebral formation, often leading to progressive spinal deformity. Segmented HV-associated scoliosis presents significant surgical challenges, requiring meticulous planning and precise execution for optimal outcomes. OBSERVATIONS: A 12-year-old female presented with severe lumbar scoliosis (75° focal curve) due to a fully segmented supernumerary HV at L3-4, causing coronal trunk shift, pelvic obliquity, and activity-limiting back pain. A short-segment L1-5 posterior instrumented fusion with vertebral column resection was performed using stereotactic navigation for pedicle screw placement and a modular screw system to optimize surgical access. The HV was resected using ultrasonic bone-cutting instruments, osteotomes, and a coarse diamond drill. Deformity correction was achieved through controlled compression and distraction forces with cobalt-chromium rods. Postoperatively, the patient experienced transient radicular pain, which resolved within 4 weeks with conservative management. LESSONS: This case highlights the challenges of delayed HV detection and the importance of advanced surgical techniques for deformity correction. Stereotactic navigation, modular instrumentation, and careful execution of a hemivertebrectomy facilitated optimal correction while preserving mobility in adjacent spinal regions. A tailored approach is critical for long-term stability and functional outcomes. https://thejns.org/doi/10.3171/CASE25244.