Early Symptom Aggravation Following Ulnar Nerve Transposition for Cubital Tunnel Syndrome: Incidence, Predictive Factors, and Threshold-Based Risk Stratification

Background Early postoperative symptom aggravation is a clinically relevant yet underexplored phenomenon following anterior ulnar nerve transposition for cubital tunnel syndrome (CuTS). This study aimed to define its incidence, identify predictive factors, and establish a threshold-based risk stratification model. Methods We retrospectively reviewed 127 patients undergoing anterior subcutaneous transposition of the ulnar nerve between 2020 and 2023. Early symptom aggravation was defined as a postoperative deterioration in at least one clinical (VAS or PRUNE) or electrophysiological (CMAP or SNCV) indicator at two weeks post-surgery. Multivariate logistic regression and ROC curve analyses were performed to determine independent predictors and optimal thresholds. Results Early symptom aggravation occurred in 26.8% of patients. Multivariate analysis identified symptom duration (OR = 1.150, p < 0.00001) as a significant independent predictor. McGowan grade III showed a moderate association (OR = 3.224, p = 0.087). ROC analysis revealed excellent discriminative ability for symptom duration (AUC = 0.890) with an optimal threshold of 24.00 months (sensitivity 82.4%, specificity 86.2%). Other variables, including electrophysiological measures and demographics, demonstrated limited predictive value. Conclusion Symptom duration and preoperative McGowan grade are key risk factors for early symptom aggravation after CuTS surgery. A simple threshold-based model can aid in preoperative counseling and expectation management. These findings highlight the need for timely surgical intervention to minimize neural deterioration and improve short-term outcomes.