Identifying clinically meaningful changes and predictors of improvement for patient-reported outcome measures in patients who undergo arthroscopic arthrolysis for post-traumatic elbow stiffness.

Abstract

Clinically meaningful outcome thresholds, including patient acceptable symptom state (PASS), minimal clinically important difference (MCID), and substantial clinical benefit (SCB), have rarely been evaluated after arthroscopic arthrolysis for post-traumatic elbow stiffness. This study therefore aimed to determine PASS, MCID, and SCB values for the pain visual analog scale (pVAS), Single Assessment Numeric Evaluation (SANE), Mayo Elbow Performance Score (MEPS), and range of motion difference (ROMD) after arthroscopic elbow arthrolysis. Sixty-five patients who underwent arthroscopic elbow arthrolysis were evaluated at a minimum of 1 year postoperatively using anchor-based methods for PASS and SCB, and a distribution-based method for MCID. Anchor questions were used to define clinically meaningful thresholds. Univariate and multivariate logistic regression analyses were performed to determine predictors of improvement for surgical outcomes. All four measures demonstrated acceptable discriminative ability (area under the curve >0.70) for PASS and SCB. The PASS, MCID, and SCB thresholds were 2.5, 1.2, and 2.5 for pVAS; 65.0, 11.9, and 12.5 for SANE; 87.5, 9.5, and 17.5 for MEPS; and 113, 15, and 58 for ROMD. Lower preoperative scores were associated with significantly higher odds ratios (ORs) for achieving all thresholds. Longer symptom duration and the presence of ulnar nerve symptoms were associated with significantly lower ORs for achieving PASS for SANE. Younger age was significantly associated with achieving higher ORs for PASS for MEPS. For ROMD, younger age, shorter symptom duration, lower BMI, and the presence of preoperative ulnar nerve symptoms were associated with significantly higher ORs for achieving PASS. After arthroscopic elbow arthrolysis, reliable PASS, MCID, and SCB thresholds were identified for pVAS, SANE, MEPS, and ROMD. Favorable outcomes were more likely in patients with poorer preoperative scores, younger age, lower BMI, and shorter symptom duration, while preoperative ulnar nerve symptoms were negatively associated with achieving PASS.