Using Percentage of Maximal Possible Improvement (MPI) to Predict High Patient Satisfaction Following the Latarjet Procedure.

Abstract

Outcome thresholds such as the minimal clinically important difference (MCID), patient acceptable symptomatic state (PASS), and substantial clinical benefit (SCB) are commonly used to define meaningful clinical improvement. However, these measures apply uniform cutoffs that do not account for individual baseline scores. Maximal Possible Improvement (MPI) offers a patient-specific approach by considering the maximal potential gain in function or reduction in pain. The percentage of MPI (%MPI) that correlates with high postoperative patient satisfaction following the Latarjet procedure has not been defined. The purpose of this study was to (1) establish %MPI thresholds predictive of high patient satisfaction for the American Shoulder and Elbow Surgeons (ASES) score, and the Patient-Reported Outcomes Measurement Information System (PROMIS) domains of Upper Extremity Function (PUE), Pain Interference (P-Interference), and Pain Intensity (P-Intensity); and (2) identify patient-level factors associated with achieving these thresholds for ASES and PUE. A retrospective review identified 81 eligible patients who underwent the Latarjet procedure with minimum 1-year follow-up. Preoperative and postoperative ASES, PUE, P-Interference, and P-Intensity scores, along with postoperative patient degree of satisfaction were recorded. Receiver operating characteristic curve analyses were performed to identify individual % MPI thresholds in each of the 4 scores that best predicted high satisfaction at minimum 1 year postoperatively. Univariate and multivariate logistic regression analyses were conducted sequentially to identify patient factors that were associated with achievement of the ASES and PUE thresholds. Among the 81 patients that met the inclusion criteria, the %MPI thresholds associated with high satisfaction were 65% for ASES (Area under the curve [AUC]: 0.86), 29% for PUE (AUC: 0.84), 57% for P-Interference (AUC: 0.78), and 59% for P-Intensity (AUC: 0.77). Higher body mass index (odds ratio [OR]: 1.16, p = 0.048) and surgery on the dominant arm (OR: 3.87, p = 0.024) were associated with higher odds of achieving the ASES threshold. Recurrent dislocations preoperatively (OR: 0.20, p = 0.022) were associated with lower odds of achieving the PUE threshold. The percentage of maximal possible improvement (%MPI) following the Latarjet procedure offers an individualized measure of clinical success and accounts for baseline variability and mitigates ceiling effects. Thresholds associated with high patient satisfaction following the Latarjet procedure were ≥65% for ASES, ≥29% for PUE, ≥57% for P-Interference, and ≥59% for P-Intensity.