脊椎変形に対する胸腰椎固定術後の術前期待と満足度の用量反応関係

Study DesignRetrospective study.ObjectiveThis study aimed to investigate the association between preoperative patient expectations and postoperative satisfaction in elderly patients with adult spinal deformity (ASD), with particular emphasis on identifying potential dose-response relationships.MethodsWe conducted a retrospective cohort study of elderly patients (aged ≥65 years) with ASD undergoing thoracolumbar fusion surgery at our institution. Participants were stratified into satisfied and dissatisfied cohorts based on postoperative the North American Spine Society (NASS) satisfaction scores assessed at follow-up. Comprehensive data collection included demographic characteristics, radiological parameters, surgical variables, and perioperative outcomes. Propensity score matching using the nearest-neighbor method was applied to both groups of patients. Conditional logistic regression models adjusted for confounders were employed to assess associations. Nonlinear relationships were investigated through smoothed curve fitting with covariate adjustment. Threshold effects were analyzed using piecewise regression models, with receiver operating characteristic (ROC) curve analysis validating optimal cutoff values.ResultsIn our study involving 234 elderly patients with ASD undergoing thoracolumbar fusion surgery between September 2019 and September 2022, we analyzed statistically significant differences between a case group (patient dissatisfied) and a control group (patient satisfied). We matched 82 patients in each group using nearest-neighbor matching. Despite this matching, there were still significant differences in key variables such as American Society of Anesthesiologists (ASA), Age-adjusted Charlson Comorbidity Index (ACCI), complications, previous spine surgery, perioperative outcomes, and preoperative expectation (P < .05). In our fully adjusted model, we found that higher expectation scores were associated with lower satisfaction levels. Our curve-fitting analysis revealed that the risk of decreased patient satisfaction increased notably when the expectation score exceeded 53 points. Two-piecewise regression confirmed this threshold (OR = 0.29, 95% CI 0.17 ∼ 0.38, P < .001), corroborated by Receiver operating characteristic (ROC) analysis (AUC = 0.808, sensitivity 83.6%, specificity 63.2%).ConclusionOur findings identify 53 points as the critical threshold on preoperative expectation scales where satisfaction risk markedly escalates in elderly spinal deformity patients undergoing thoracolumbar fusion. The demonstrated dose-response relationship underscores the clinical importance of preoperative expectation management in this population.