The Quest of Sagittal Balance Parameters and Clinical Outcome after Short Segment Spinal Fusion

INTRODUCTION: Sagittal imbalance leads to muscular distress and results in low back pain. OBJECTIVES: This study scrutinize the segmental impact of short spinal fusion on spinopelvic parameters and the global patient’s clinical outcome. MATERIALS AND METHODS: A retrospective analysis evaluated 56-patients who underwent lumbar fusion surgery at Klinikum Dortmund, from July 2013 to February 2014. The population was allocated into two groups: (1-level group), (2-levels group). EOS imaging applied for radiological evaluation and measurements of the following spinopelvic parameters: pelvic incidence (PI), sacral slope (SS), pelvic tilt (SS), lumbar lordosis (LL), and sagittal vertical axis (SVA). The radiological measurements were implemented during the preoperative, postoperative, 3 months and 1 year follow-up visits. All patients completed clinical questionnaires. RESULTS: Statistically, the Pearson correlation coefficient revealed in the 1-level group that the clinical parameters correlated with the PT (R=0.40), SSA (R=-0.38) and SVA (R=-0.41) (p<0.05). While clinically, the mean preoperative VAS and mean ODI improved significantly in both groups.There was also a high correspondence between LL and SS (R=0.90); this relationship persisted at the same level even after a year. For the 2-level group, the only parameter that was interrelated with clinical parameters was the SVA (R=0.49) (p<0.05). There was also a high correlation between LL and SS (R=0.88). CONCLUSION: Scrutiny conducted showed: Patient with one level would improve clinically in terms of pain and radiculopathy, with only small alterations in spino-pelvic parameters. Meanwhile, two-level fusions have a statistically substantial clinical improvement interrelated to re-establishment of lumbar lordosis and sagittal vertical axis.