RESUMEN
STUDY DESIGN: Retrospective observational study. OBJECTIVE: The study objectives were to: (1) determine radiographically which spinal malalignment parameters predominantly influence the risk of gastroesophageal reflux disease (GERD); (2) evaluate the outcome of GERD 2 years after surgery for adult spinal deformity (ASD); and (3) clarify key factors that influence the improvement of postoperative GERD in ASD. SUMMARY OF BACKGROUND DATA: Spinal deformity is reported to be involved in the pathology of GERD. Our previous study found that approximately 50% of patients treated surgically for ASD had GERD symptoms. However, the postoperative progress of GERD and the key factors that influence the improvement of postoperative GERD are largely unknown. METHODS: Ninety-two patients with ASD treated with thoracolumbar corrective surgery and followed up for a minimum of 2 years were enrolled. All patients were asked to complete the Frequency Scale for Symptoms of GERD (FSSG) questionnaire preoperatively and at 1 and 2 years after surgery. GERD was diagnosed by FSSG score more than 8 points. Before, and at 1 and 2 years after surgery, full-length lateral radiographs were taken and radiographic parameters were obtained. RESULTS: Patients were classified into two groups based on GERD symptoms, with 47 (51.1%) in the GERD+ group. Among parameters assessed, only thoracolumbar kyphosis (TLK) was significantly greater in the GERD+ group than in the GERD- group. The FSSG score improved significantly 1 year after surgery, but no significant difference was found between groups at 2 years. A significant correction loss of TLK was observed 2 years after surgery. There was a significant highly positive correlation between the FSSG score and TLK at 2 years after surgery. CONCLUSION: GERD improved with correction of the spinal deformity but significant correction loss of the TLK even within the fusion presumably due to subsidence or proximal junctional kyphosis resulted in a cessation of that improvement over time. LEVEL OF EVIDENCE: 3.