Biomechanical - Instrumentation

Optimal distal fixation construct for the surgical treatment of thoracic hyperkyphosis: A biomechanical analysis

Failure of the distal fixation construct is a significant problem for patients undergoing surgical treatment for thoracic hyperkyphosis.

Researchers in the Orthopedic Biomechanics Laboratory have recently concluded a study which tested the hypothesis that infralaminar hooks or sublaminar wires significantly increase the mechanical performance of pedicle screws used at the terminal end of long spinal constructs in response to forward bending.

Investigators compared the mechanical form of five constructs used to terminate dual-rod posterior spinal instruments in response to forward flexion moment, and concluded that distal fixation constructs consisting of pedicle screws give a greater pullout strength and firmness when compared to wires or hooks alone. Supplementing the screws with infralaminar hooks or sublaminar wires provides additional enhancement in the mechanical performance of the construct.