Spine Deformity · Dec 27, 2025

Less is more: in situ delta fixation achieves functional success in elderly osteoporotic patients with high-grade spondylolisthesis

By Tandon V, Sangondimath G, Kumar G et al.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To evaluate clinical and radiological outcomes following in situ transdiscal L5-S1 fixation (delta fixation) in elderly osteoporotic patients with high-grade spondylolisthesis, with emphasis on functional recovery and changes in sagittal spinopelvic alignment. METHODS: 15 patients aged > 60 years (mean age 74.9 ± 14.8 years) with Meyerding Grade III-IV L5-S1 spondylolisthesis and osteoporosis (DEXA T score ≤ - 2.5) underwent posterior-only in situ transdiscal fixation and neural decompression. Pre- and postoperative spinopelvic parameters were assessed using standing radiographs and Surgimap® software. Functional outcomes were evaluated using the Oswestry Disability Index (ODI) and the Visual Analog Scale (VAS) for back and leg pain, with a minimum follow-up of 24 months. RESULTS: All patients demonstrated significant functional improvement. ODI improved from 66.8 ± 7.1 to 37.3 ± 5.1 (p < 0.001), VAS for low back pain from 8.3 ± 1.5 to 2.7 ± 0.5 (p < 0.001), and VAS for leg pain from 4.5 ± 1.7 to 1.2 ± 0.6 (p < 0.001). Among sagittal parameters, significant improvements were observed in thoracic kyphosis (p = 0.006), sagittal vertical axis (p = 0.010), and PI-LL mismatch (p = 0.032). Changes in pelvic incidence, pelvic tilt, lumbar lordosis, and sacral slope were not statistically significant. CONCLUSIONS: In situ delta fixation with neural decompression offers substantial clinical benefit in elderly osteoporotic patients with high-grade L5-S1 spondylolisthesis. Functional recovery occurred despite limited changes in local spinopelvic sagittal alignment, highlighting that global compensation and neural decompression may suffice for clinical improvement in this high-risk population. LEVEL OF EVIDENCE: Level IV-Case series.

doi.org/10.1007/s43390-025-01260-3PubMed 41455089Interventions