Background: The Spinal Cord Shape Classification System (SCSCS) class has been associated with spinal cord monitoring data loss during spinal deformity surgery. The objective of the current study was to prospectively validate the SCSCS as a predictor of spinal cord monitoring data loss during spinal deformity surgery. Methods: A prospective cohort study of consecutive patients who were undergoing primary deformity surgery at a single institution from 2018 to 2023 and whose major curve was in the spinal cord region was undertaken. Spinal cord morphology at the apex of the major curve on preoperative axial T2-weighted magnetic resonance imaging was used to categorize patients into 3 spinal cord shape types based on the SCSCS. The primary outcome was intraoperative neuromonitoring (IONM) data loss related to spinal cord dysfunction. Demographics and surgical and radiographic variables were compared between patients with IONM data loss and those without loss. Predictors of IONM loss were determined using bivariate and multivariable logistic regression analyses. Results: A total of 256 patients (168 adult, 88 pediatric) were included and were separated into 3 SCSCS types: 110 (43.0%) with Type I, 105 (41.0%) with Type II, and 41 (16.0%) with Type III. IONM loss was observed in 30 (11.7%) of the 256 patients, including 7 (6.4%) of 110 with SCSCS Type I, 7 (6.7%) of 105 with Type II, and 16 (39.0%) of 41 with Type III. IONM loss was associated with SCSCS Type III, the preoperative deformity angular ratio, performance of 3-column osteotomies, greater operative time, greater transfusion volume, and greater postoperative sagittal corrections. SCSCS type was the strongest independent predictor of IONM data loss. SCSCS Type III had the greatest odds of IONM loss (odds ratio [OR] = 6.68, 95% confidence interval [CI] = 2.45 to 18.23 compared with Types I and II combined). The overall predictive performance with respect to IONM loss (area under the receiver operating characteristic curve = 0.827) was considered excellent. Conclusions: This prospective cohort study of patients undergoing spinal deformity correction confirmed that patients with a Type-III spinal cord shape had greater odds of IONM loss. Inclusion of the SCSCS in preoperative risk stratification and intraoperative management of spinal deformity corrective surgery is recommended. Level of Evidence: Prognostic Level II . See Instructions for Authors for a complete description of levels of evidence.
Impact of Unplanned Readmission on Patient-Reported Outcomes After Cervical Spine Surgery: A National Study of 13 355 Patients
BACKGROUND AND OBJECTIVES: Although risk factors for unplanned readmission after cervical spine surgery have been widely reported, less is known about how readmission itself affects patient-reported outcome measures (PROMs). Using the Quality Outcomes Database registry of patients undergoing elective cervical spine surgery, we sought to (1) determine the impact of unplanned readmission on PROMs and (2) compare the effect of specific readmission reasons on PROMs. METHODS: An observational study was performed using a multi-institution, retrospective registry for patients undergoing cervical spine surgery. The occurrence of 90-day unplanned readmission classified into medical, surgical, pain only, and no readmissions was the exposure variable. Outcome variables included 12-month PROMs of Neck Disability Index (NDI), Numeric Rating Scale (NRS)-neck/arm pain, EuroQol-5D (EQ-5D), and patient dissatisfaction. Multivariable models predicting each PROM were built using readmission reasons controlling for demographics, clinical characteristics, and preoperative PROMs. RESULTS: Data from 13 355 patients undergoing elective cervical spine surgery (82% anterior approach and 18% posterior approach) were analyzed. Unplanned readmission within 90 days of surgery occurred in 3.8% patients, including medical (1.6%), surgical (1.8%), and pain (0.3%). Besides medical reasons, wound infection/dehiscence was the most common reason for unplanned readmission for the total cohort (0.5%), dysphagia in the anterior approach (0.6%), and wound infection/dehiscence in the posterior approach (1.5%). Based on multivariable regression, surgical readmission was significantly associated with worse 12-month NDI, NRS-neck pain, NRS-arm pain, EQ-5D, and higher odds of dissatisfaction. Pain readmissions were associated with worse 12-month NDI and NRS-neck pain scores, and worse dissatisfaction. For specific readmission reasons, pain, surgical site infection/wound dehiscence, hematoma/seroma, revision surgery, deep vein thrombosis, and pulmonary embolism were significantly associated with worsened 12-month PROMs. CONCLUSION: In patients undergoing elective cervical spine surgery, 90-day unplanned surgical and pain readmissions were associated with worse 12-month PROMs compared with patients with medical readmissions and no readmissions.