Older Age, Female Sex, Chronic Injury, and Higher Preoperative Patient‐Reported Outcome Scores Predict the Failure to Achieve the Maximal Outcome Improvement Thresholds Anchored by Patients’ Willingness to Undergo Posterior Cruciate Ligament Reconstruction

Purpose To determine the maximal outcome improvement (MOI) thresholds for International Knee Documentation Committee (IKDC) score and Lysholm score anchored by patients’ willingness to undergo posterior cruciate ligament (PCL) reconstruction again and identify predictors of failure to achieve these thresholds. Methods A retrospective review was conducted on patients who underwent primary PCL reconstruction. MOI was defined as the percentage of postoperative improvement relative to maximum possible improvement. Receiver‐operating characteristic analyses were performed to determine the MOI thresholds based on patients’ willingness to undergo PCL reconstruction as assessed through an anchor question at final follow‐up. Multivariable logistic regression analyses were performed to identify predictors of failure to achieve these thresholds. Results A total of 217 patients were included, with a median follow‐up of 63 months (range: 36‐84 months). MOI thresholds were 34.5% for IKDC score (area under curve = 0.837) and 37.2% for Lysholm score (area under curve = 0.825), where the latter was calculated after excluding 11 patients with perfect preoperative scores. The proportions of patients achieving the MOI thresholds were 68.7% for IKDC score and 56.3% for Lysholm score. Independent predictors of failure to achieve these MOI thresholds included older age (odds ratio OR = 0.952), female sex (OR = 0.166), chronic injury (>12 months; OR = 0.377), and higher preoperative IKDC score (OR = 0.947). For Lysholm score, significant predictors included female sex (OR = 0.403), chronic injury (OR = 0.452), and higher preoperative Lysholm score (OR = 0.968). Conclusions MOI thresholds for patients’ willingness to undergo PCL reconstruction were 34.5% (IKDC score) and 37.2% (Lysholm score), achieved by 68.7% and 56.3% of patients, respectively. Older age, female sex, chronic injury (>12 months), and higher preoperative patient‐reported outcome scores were negative predictors of achieving these MOI thresholds. Level of Evidence Level IV, retrospective case series.