Sagittal Balance After Posterior Instrumentation in Lumbar Fractures

Abstract

Objective: When a lumbar fractures developes a significant deformity, the sagittal balance is altered which can lead to clinical consequences. The aim of this study was to measure and analyze the sagittal balance in patients with lumbar fractures operated with posterior instrumentation after three months and analyze their correlation with the different variables of the patient and the fracture. Methods: Sixty-three medical records of patients with lumbar fracture operated with posterior instrumentation were analyzed, excluding those with previous spinal pathology, or inability to stand upright. The parameters of pelvic incidence, sacral slope, pelvic tilt, lumbar lordosis, lumbar lordosis/pelvic incidence (LL/ PI) ratio, as well as the pre and postoperative status of segmental kyphosis and residual pain were measured. Results: Eighteen women, 44 men, with mean age of 42 years, with lumbar fractures: 29 in L1, 19 in L2, 10 in L3, 3 in L4 and 1 in L5. AOSpine Clasification: 2 type A1, 2 type A2, 37 type A3, 19 type A4, 2 type B. All patients were operated with a transpedicular polyaxial system. More than 80% of patients with spinopelvic balance within parameters considered normal. More than 70% with lumbar lordosis and LL/PI ratio within parameters. All with improvement of segmental kyphosis (average correction of 8.5°, p<.000). Final mean VAS of 1.85. Conclusions: The posterior instrumentation with a polyaxial system allows acceptable corrections of the segmental kyphosis of lumbar fractures. No statistically significant correlation was found between sagittal balance parameters, and characteristics of the patient and fracture. Level of Evidence IV; Case series.