A Clinical Prediction Rule for Clinical Outcomes in Patients Undergoing Surgery for Degenerative Cervical Myelopathy: Analysis of an International AOSpine Prospective Multicenter Data Set of 743 Subjects

Abstract

Introduction Knowledge of important clinical predictors of surgical outcome can provide decision support to surgeons and enable them to appropriately manage their patients' expectations. This study aims to determine the most important global clinical predictors of surgical outcome in patients undergoing surgery for CSM, based on data from two multicenter prospective studies. Patients and Methods A total of 743 surgical patients with CSM participated in either the CSM-North America or CSM-International study. The model was developed to distinguish between patients with mild myelopathy postoperatively (mJOA ≥ 16) and those with substantial residual neurological impairment (mJOA < 16). Univariate analyses were performed to evaluate the relationship between outcome and various clinical predictors. Multivariate logistic regression was used to formulate the final prediction model. Results Univariate analyses demonstrated that the odds of achieving a score ≥ 16 decreased with the presence of certain symptoms, including impaired gait; the presence of certain signs such as lower limb spasticity; positive smoking status; a higher comorbidity score; more severe preoperative myelopathy; and older age. The final prediction model included age (OR = 0.97, p = 0.0017), duration of symptoms (OR = 0.88, p = 0.049), smoking status (OR = 0.51, p = 0.0018), impairment of gait (OR = 1.94, p = 0.0168), broad-based unstable gait (OR = 1.75, p = 0.0133), baseline severity (OR = 1.23, p < 0.0001), and comorbidity score (OR = 0.84, p = 0.0030). Conclusion Patients are more likely to achieve a score ≥ 16 if they are younger, have a shorter duration of symptoms, are less severe preoperatively, do not smoke, and do not have comorbidities or evidence of gait dysfunction.