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

Retrospective case series.

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.

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.

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.

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 IV-Case series.