Prevention of lower instrumented vertebra pedicle screw failure in multilevel constructs for adult spinal deformity surgery using hybrid hook-screw constructs.

Abstract

Objective: The aim of this study was to evaluate the effectiveness of hybrid hook-screw constructs in preventing distal junctional failure (DJF) and to assess radiographic outcomes in multilevel adult spinal surgery.

Methods: This retrospective study analyzed 53 patients who underwent multilevel thoracolumbar fixation from January 2014 to December 2020, with a minimum follow-up of 1 year. DJF was categorized into bony failure, ligamentous failure, and screw failure. Patients were divided into 2 groups according to receiving a pedicle screw (PS)-only construct (PS group) or hybrid hook-screw construct (hybrid group). Kaplan-Meier analysis and logistic regression were used to evaluate survival rates and predictors of DJF.

Results: No significant differences in demographic or surgical characteristics were observed between the 2 groups. Screw failure rates were significantly lower in the hybrid group (5.6%) compared with the PS group (42.9%, p = 0.042). Kaplan-Meier analysis revealed a 1-year survival rate for avoiding screw failure of 100% in the hybrid group versus 50% in the PS group (p = 0.031). However, ligamentous failure occurred more frequently in the hybrid group (33.3%) compared with none in the PS group (p = 0.002). Overall, DJF rates did not differ significantly between the 2 groups.

Conclusions: Hybrid hook-screw constructs reduced screw failure but were associated with an increased incidence of ligamentous failure. Although overall DJF rates remained comparable, careful patient selection and further investigation are warranted to optimize the clinical utility of hybrid constructs in multilevel spinal surgeries.