Functional Recovery and Home Discharge after Spine Surgery in Nonagenarians: The Role of Cognitive Status and Acute Exacerbation of Cervical Myelopathy

Introduction: Spine surgery in nonagenarians remains challenging because of concerns regarding frailty, cognitive impairment, perioperative complications, and postoperative loss of independence. This study aimed to evaluate functional recovery and discharge destination after spine surgery in patients aged 90 years and older, with particular attention given to cognitive status, baseline functional dependence, and disease acuity.Methods: This retrospective single-center observational study included consecutive patients aged 90 years and older who underwent spine surgery between April 2021 and October 2025. Functional outcomes were assessed using the modified Rankin Scale and Functional Independence Measure before surgery and at discharge. Perioperative complications, postoperative delirium, and discharge destination were evaluated. Factors associated with unfavorable outcomes, including unchanged or worsened functional status and institutional discharge, were explored.Results: A total of 27 patients were included. The median modified Rankin Scale score improved from 4 to 2 (p < 0.001), and the median Functional Independence Measure score improved from 61 to 85 (p < 0.001). Perioperative complications occurred in six patients, postoperative delirium in five, and one patient died during hospitalization. Among 24 patients who had been living at home before admission, 17 (70.8%) were discharged home. Unfavorable outcomes were associated with dementia history, lower preoperative functional status, lower cognitive scores, and acute exacerbation of cervical spondylotic myelopathy. In exploratory multivariable analysis, acute exacerbation of cervical spondylotic myelopathy was associated with unchanged or worsened modified Rankin Scale score at discharge.Conclusions: In selected nonagenarians, spine surgery was associated with meaningful functional improvement, and most patients admitted from home were discharged home. However, cognitive impairment, poor baseline functional status, and acute exacerbation of cervical spondylotic myelopathy were associated with unfavorable recovery or institutional discharge. These exploratory findings may help inform preoperative counseling and perioperative planning in nonagenarians undergoing spine surgery.