Establishing the Minimal Clinically Important Difference,Substantial Clinical Benefit,and Patient Acceptable Symptomatic State for Patient-Reported Outcome Measures After Primary Posterior Cruciate Ligament Reconstruction With a Minimum 5-Year Follow-up

Abstract

Background:

Improvements in patient-reported outcome measure (PROM) scores have been widely documented after posterior cruciate ligament reconstruction (PCLR). Establishing clinically significant outcome (CSO) benchmarks for PROMs can enhance their clinical applicability.

Purpose:

To establish the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) for PROMs after primary PCLR and identify the predictors of achieving them.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

This retrospective study analyzed 157 patients who underwent primary PCLR between April 2016 and October 2019. PROM scores, including the International Knee Documentation Committee (IKDC) score, Lysholm score, and Tegner score, were assessed preoperatively and at a minimum 5-year follow-up. The PASS and SCB were determined by anchor questions, while the MCID was calculated using the distribution-based method. Multivariable logistic regression analyses were performed to identify the predictors of achieving CSO benchmarks.

Results:

The MCID, SCB, and PASS were 9.02, 16.09, and 80.46 for the IKDC score, respectively; 9.94, 11.00, and 85.00 for the Lysholm score, respectively; and 0.98, 2.00, and 5.00 for the Tegner score, respectively. Increased age was a negative predictor of achieving the MCID for the IKDC score as well as the PASS for both the IKDC score and Tegner score. Male sex positively predicted achieving CSO benchmarks for the IKDC score and Tegner score as well as the SCB for the Lysholm score. A higher preinjury Tegner score was positively associated with the achievement of CSO benchmarks for both the IKDC score and Lysholm score. A chronic injury (>6 months) was associated with the failure to achieve the MCID for the Tegner score, while a medial compartment cartilage lesion was associated with the failure to achieve the MCID for the IKDC score. Additionally, higher preoperative scores predicted failure to achieve the MCID and SCB for all PROMs but predicted success in achieving the PASS for the Tegner score.

Conclusion:

This study established MCID, SCB, and PASS values for the IKDC score, Lysholm score, and Tegner score after primary PCLR. Negative predictors of achieving these CSO benchmarks included increased age, chronic injury, and medial compartment cartilage lesion, while male sex and higher preinjury Tegner score were positive predictors. Additionally, higher preoperative scores served as negative predictors of achieving the MCID and SCB for the PROMs.