Factors predicting long-term outcome after short-segment posterior fixation for traumatic thoracolumbar fractures

BACKGROUND The "gold standard" for instrumentation of unstable thoracolumbar fracture-dislocations is pedicle screw and rod fixation. Although traditional treatment supports long-segment posterior fixation (LSPF), more recent studies show short-segment posterior fixation (SSPF) may be effective, but incur higher failure rates. Here, we evaluated the effectiveness of SSPF in the management of unstable thoracolumbar injuries and analyzed the factors impacting long-term outcomes. METHODS In this retrospective analysis of 91 patients with thoracolumbar fractures managed with SSPF alone, we assessed the clinical and radiological parameters at preoperative, postoperative, and follow-up intervals along with reasons for failures of SSPF. RESULTS We analyzed 91 patients (mean age: 33.5 years; Male: Female = 50:41) with thoracolumbar fractures treated with SSPF over a median follow-up period of 30 months. SSPF failures were observed in 26 of 91 (28.6%) patients; the median time to implant failure was 17 months. On univariate analysis, statistically significant factors contributing to failure of SSPF included the presence of a burst fracture, a preoperative LSC (load-sharing classification) score >6, and translation/dislocation. With multinomial regression analysis, the only factor predictive for SSPF failure was the patients' postoperative ambulatory status. CONCLUSION Patients with thoracolumbar facture dislocations, subjected to axial spinal loading postoperatively, should not be considered for SSPF alone. The following factors also contributed to SSPF failures: a burst fracture, a preoperative LSC score of >6, and/or presence of transverse dislocation.