Yusuf ALTUNTAŞ, İsmail TÜTER, Necmi CAM, Mehmet Ali TALMAC, Hacı Mustafa ÖZDEMİR
Düzce Tıp Fakültesi Dergisi - 2026;28(2):157-165
Aim: To compare clinical outcomes, radiographic parameters, and mechanical complications between 2-rod and 3-rod posterior instrumentation systems in patients undergoing long-segment fusion for degenerative spinal disorders. Material and Methods: This retrospective study included 66 patients who underwent posterior-only corrective spinal fusion for degenerative spinal disorders. Clinical outcomes were assessed using the Visual Analog Scale (VAS) and Oswestry Disability Index (ODI). Radiographic parameters including Cobb angle, lumbar lordosis, pelvic incidence, pelvic tilt, and sacral slope were evaluated preoperatively, in the early postoperative period, at 1 year, and at final follow-up. Mechanical complications, including mechanical failure associated with pseudarthrosis requiring revision surgery and proximal junctional kyphosis, were recorded. Results: A total of 66 patients were included, including 34 patients in the 2-rod group and 32 patients in the 3-rod group. Both groups demonstrated significant improvements in radiographic parameters and patient-reported outcomes during follow-up. Mechanical failure associated with pseudarthrosis requiring revision surgery occurred in four patients (11.7%) in the 2-rod group and in none of the patients in the 3-rod group. Proximal junctional kyphosis developed in 14.7% and 15.6% of patients, respectively. Repeated-measures analysis demonstrated significant improvements over time in VAS and ODI scores in both groups, without significant differences between groups. Conclusion: Both 2-rod and 3-rod posterior instrumentation systems were associated with significant improvements in clinical and radiographic outcomes. Although mechanical failure was more frequently observed in the 2-rod group, no corresponding differences were observed in patient-reported outcomes. Given the retrospective, non-randomized design, these findings should be interpreted with caution and confirmed in larger prospective studies.
