Predictability of Magerl & McCormack's Load Sharing Classification on the Metal Failure after Pedicle Screw Fixation in the Thoracolumbar Spine Fracture / 대한척추외과학회지

ABSTRACT

STUDY DESIGN: A retrograde study of metal failures at thoracolumbar spinal fractures fixed using pedicle screws. OBJECTIVES: The predictability and usefulness of the McCormack's classifications for metal failures was compared with Magerl's classifications. SUMMARY OF LITERATURE REVIEW: The load sharing classification was introduced to predict metal failure after short-segmental pedicle screw fixation by McCormack. However, its reliability is uncertain. MATERIALS AND METHODS: From July 2000 to July 2003, this study examined the plain radiographs and CT images of 31 out of 46 patients who underwent posterior stabilization using pedicle screws for thoracolumbar fractures and could be followed up at least 1 year. Fractures were classified utilizing Denis's, Magerl's, and McCormack's systems. RESULTS: As a result of analysis of relation between metal failure and classification system by Magerl or McCormack, there was no significant difference in its distribution. There was no correlation between the fixation range and metal failures in type C3 fractures, but there was a correlation between short fixation and metal failures in rotational burst fractures in short fixation. CONCLUSIONS: In order to prevent metal failures after fixing thoracolumbar spinal fractures by pedicle screws, the stability should be evaluated using Magerl's classification and McCormack's total score. In addition, in cases of type C3 fractures according to the Magerl's classification, reconstructions should be carried out with a long segment fixation or anterior supporting bone grafts, particularly when McCormack's total score is greater than 7.