Bilateral pedicle screw fixation provides superior biomechanical stability in transforaminal lumbar interbody fusion: a finite element study.

Background Context: Transforaminal lumbar interbody fusion (TLIF) is increasingly popular for the surgical treatment of degenerative lumbar disease. The optimal construct for segmental stability remains unknown.

Purpose: To compare the stability of fusion constructs using standard (C) and crescent-shaped (CC) polyetheretherketone TLIF cages with unilateral (UPS) or bilateral (BPS) posterior instrumentation.

Do stand-alone interbody spacers with integrated screws provide adequate segmental stability for multilevel cervical arthrodesis?

Background Context: Some postoperative complications after anterior cervical fusions have been attributed to anterior cervical plate (ACP) profiles and the necessary wide operative exposure for their insertion. Consequently, low-profile stand-alone interbody spacers with integrated screws (SIS) have been developed. Although SIS constructs have demonstrated similar biomechanical stability to the ACP in single-level fusions, their role as a stand-alone device in multilevel reconstructions has not been thoroughly evaluated.

The biomechanical consequences of rod reduction on pedicle screws: should it be avoided?

Background Context: Rod contouring is frequently required to allow for appropriate alignment of pedicle screw-rod constructs. When residual mismatch is still present, a rod persuasion device is often used to achieve further rod reduction. Despite its popularity and widespread use, the biomechanical consequences of this technique have not been evaluated.

The biomechanical effect of pedicle screw hubbing on pullout resistance in the thoracic spine.

Background Context: The biomechanical fixation strength afforded by pedicle screws has been strongly correlated with bone mineral density. It has been postulated that "hubbing" the head of the pedicle screw against the dorsal laminar cortex provides a load-sharing effect, thereby limiting cephalocaudad toggling and improving the pullout resistance of the pedicle screw.

Purpose: To evaluate the pullout strength (POS) of monoaxial hubbed pedicle screws versus standard fixation in the thoracic spine.