Striking a Balance: The Role of Alignment, Surgical Techniques, and Multi-Rod Constructs in Reducing Rate of Rod Fractures in Adult Spinal Deformity Surgery.

Abstract

Study designRetrospective Cohort Study.ObjectivesRod fracture (RF) is a frequent mechanical complication in adult spinal deformity (ASD) surgery, often requiring revision and impairing quality of life. Despite improved alignment strategies and surgical techniques, RF risk remains. This study aimed to identify predictors of RF and evaluate the protective effect of multi-rod constructs.MethodsWe retrospectively reviewed 140 ASD patients who underwent posterior spinal fusion between 2015 and 2023. Demographic, radiographic, and operative data were collected. Logistic regression was used to identify predictors of RF and their impact on outcomes.ResultsUnivariate analysis showed that higher pelvic incidence (PI) (56.5° vs 60.5°, <i>P</i> = .037) and pelvic tilt (PT) (25.8° vs 28.7°, <i>P</i> = .042) were significantly associated with RF. Inadequate correction of PI-lumbar lordosis mismatch (<i>P</i> = .041) also predicted RF. Anterior column manipulation with anterior lumbar interbody fusion (ALIF, <i>P</i> = .004) or anterior column realignment (ACR, <i>P</i> = .045) increased RF risk, whereas multi-rod constructs reduced it (<i>P</i> = .012). On multivariate analysis, ALIF/ACR remained the only independent predictor (OR 4.69, 95% CI 1.66-13.25, <i>P</i> = .004). Clinically, RF correlated with prolonged opioid use (<i>P</i> = .016) and higher Oswestry Disability Index scores (<i>P</i> = .003), reflecting functional impairment, though not directly with pain scores.ConclusionRF in ASD surgery is influenced by spinopelvic parameters, surgical technique, and construct design. High PI and PT and poor sagittal correction elevate risk, but anterior column manipulation (particularly ALIF/ACR) is the most robust independent predictor. Multi-rod constructs provide significant protection. Clinically, RF is associated with extended opioid use and functional decline.