The Relationship Between Endplate Defect Scores and Lumbar Sagittal Translation Stability in Lumbar Spondylolisthesis Patients

Abstract

BackgroundLumbar instability and endplate defects are commonly seen in patients with spondylolisthesis. However, little is known about associations between segmental stability and endplate defects. The present study explored associations between stability-related radiographic parameters and endplate defect scores and assessed whether endplate defect scores can predict lumbar stability in lumbar spondylolisthesis. MethodsNeutral, flexion and extension radiographs of 159 patients with monosegmental lumbar spondylolisthesis were analyzed. Radiographic parameters included average intervertebral disc height (IDH), slip distance, sagittal translation (ST) and sagittal angulation (SA). Correlation analysis and linear regression analysis were used to explore associations between endplate defect scores and radiographic parameters. Logistic regression analysis was used to assess associations between endplate defect scores and ST stability. Receiver-operating characteristic curve (ROC) analysis was used to evaluate the value of the endplate defect score in predicting ST stability. ResultsA total of 11.9% of patients had ST≥4 mm, and 30% of patients had SA≥10 degrees. Endplate defect scores were negatively correlated with ST and IDH and positively correlated with slip distance in isthmic spondylolisthesis but not in degenerative spondylolisthesis. In multiple regression analysis, endplate defect scores were significantly associated with ST, slip distance, IDH, and disc degeneration. ST instability was associated with endplate defect scores in isthmic spondylolisthesis (OR=0.460, P=0.010). The AUCs for using the endplate defect score to evaluate ST stability in overall patients and isthmic spondylolisthesis patients were 0.672 and 0.774, respectively. The optimal threshold of the endplate defect score constructed by the Youden index was 7.5 for predicting ST stability. ConclusionsEndplate defect scores increase with a reduction in IDH, progression of slippage and a decrease in ST in isthmic spondylolisthesis but not in degenerative spondylolisthesis. ST instability was associated with endplate defect scores in isthmic spondylolisthesis, and endplate defect scores could be used to reflect lumbar stability at the slippage segment.