Short segment pedicle screw instrumentation with an index level screw and cantilevered hyperlordotic reduction in the treatment of type-A fractures of the thoracolumbar spine

Abstract

The purpose of this study was to evaluate and compare the effect of short segment pedicle screw instrumentation and an intermediate screw (SSPI+IS) on the radiological outcome of type A thoracolumbar fractures, as judged by the load-sharing classification, percentage canal area reduction and remodelling. We retrospectively evaluated 39 patients who had undergone hyperlordotic SSPI+IS for an AO-Magerl Type-A thoracolumbar fracture. Their mean age was 35.1 (16 to 60) and the mean follow-up was 22.9 months (12 to 36). There were 26 men and 13 women in the study group. In total, 18 patients had a load-sharing classification score of seven and 21 a score of six. All radiographs and CT scans were evaluated for sagittal index, anterior body height compression (%ABC), spinal canal area and encroachment. There were no significant differences between the low and high score groups with respect to age, duration of follow-up, pre-operative sagittal index or pre-operative anterior body height compression (p = 0.217, 0.104, 0.104, and 0.109 respectively). The mean pre-operative sagittal index was 19.6° (12° to 28°) which was corrected to -1.8° (-5° to 3°) post-operatively and 2.4° (0° to 8°) at final follow-up (p = 0.835 for sagittal deformity). No patient needed revision for loss of correction or failure of instrumentation. Hyperlordotic reduction and short segment pedicle screw instrumentation and an intermediate screw is a safe and effective method of treating burst fractures of the thoracolumbar spine. It gives excellent radiological results with a very low rate of failure regardless of whether the fractures have a high or low load-sharing classification score.

Short term radiological outcome of inserting screw at fracture level in posterior short segment fixation in thoracolumbar burst fractures

“…It had been shown in various long term studies that fusion is not necessary to maintain the correction in kyphotic deformity in these fractures even in short segment fi xation 23 . Improvement in clinical outcomes was observed in all patients, and two cases of implant failure were found.…”

“…Previous studies have concluded that an LSC six or less is likely to be good candidates, while an LSC seven or more requires the anterior approach to reconstruct the anterior column 14 . However, the signifi cance of LSC has been questioned in thoracolumbar fractures as many studies have shown to have excellent results with posterior only fi xation with intermediate screws at fracture site in patients with LSC score more than seven 23 .…”

Which anatomic structures are responsible for the reduction loss after hybrid stabilization of osteoporotic fractures of the thoracolumbar spine?

“…Thus, a persistent re-creation of the anatomic alignment might have positive impact on the clinical outcome, particularly in the long-term. Possible solutions to reduce the amount of reduction loss might be the additional implementation of fracture screws that increase stability or additional posterior fusion [23].…”

Posterior short-segment fixation with implanting pedicle screw in the fractured level as a feasible method for treatment of thoracolumbar fracture

“…Short-segment posterior fixation with pedicle fixation at the level of the fracture (short same-segment fixation) suggests biomechanical advantages toward maintenance of kyphosis correction and reducing failure rates [8]. The trans-pedicular short same-segment construct represents an attempt to rebuild the anterior column without the need for anterior strut graft or plate fixation, hence, avoiding extensive arthrodesis of the motion segments and limited surgery-related injury [9].…”