Anterior reconstruction using femoral ring allografts for thoracolumbar infectious spondylitis: Clinical and radiologic outcomes of a retrospective cohort study

Surgical treatment is required in infectious spondylitis when conservative management fails or vertebral destruction causes instability. Autologous bone graft is considered the gold standard but is limited by donor-site morbidity and availability. Femoral ring allografts are widely used in degenerative conditions, but their role in infectious spondylitis is unclear. This study evaluated the clinical, radiologic, and laboratory outcomes of anterior reconstruction using femoral ring allografts. In this single-center retrospective cohort study, reported in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology statement, we reviewed 25 patients who underwent anterior corpectomy and reconstruction using femoral ring allografts followed by posterior instrumentation between December 2011 and September 2023. Clinical outcomes (VAS, Oswestry Disability Index, Frankel grade), laboratory parameters (erythrocyte sedimentation rate, C-reactive protein), and radiologic outcomes (Cobb angle, fusion) were compared preoperatively and at final follow-up. Paired comparisons used the Wilcoxon signed-rank test, with Hodges-Lehmann estimates, distribution-free 95% confidence intervals (CIs), and effect sizes (r). Infection control and complications were analyzed. The mean follow-up was 29.2 ± 23.9 months (range, 12.0-87.2 months). VAS improved from 7.3 ± 1.1 to 1.9 ± 1.0 (Hodges-Lehmann estimate -5.50; 95% CI, -6.00 to -5.00; r = 0.87) and Oswestry Disability Index from 37.7 ± 5.9 to 10.7 ± 3.5 (-26.50; 95% CI, -29.50 to -23.50; r = 0.87; both P < .001). Neurological function improved significantly (r = 0.76, P < .001). Erythrocyte sedimentation rate and C-reactive protein decreased significantly (both P < .001). Sagittal alignment was corrected with partial loss over time but remained improved at final follow-up (5.55°; 95% CI, 3.40°-8.95°; r = 0.69; P < .001). Fusion was achieved in 92% and infection control in 96%. Complications occurred in 16%. In patients with large anterior column defects not amenable to tricortical iliac autograft, femoral ring allograft reconstruction achieved reliable infection control, a high fusion rate, and satisfactory clinical and radiologic outcomes over a mean follow-up of 29.2 months. Within this period, it appears a reasonable alternative to structural autograft when donor-site morbidity or graft availability is a concern. Longer-term comparative studies are needed to confirm the durability of graft incorporation and to define its role relative to contemporary titanium-based reconstruction.