Establishing the Minimal Clinically Important Difference and Patient-Acceptable Symptomatic State After Arthroscopic Meniscal Repair and Associated Variables for Achievement

Abstract

Purpose: To establish the minimal clinically important difference (MCID) and patient-acceptable symptomatic state (PASS) after arthroscopic meniscal repair and identify the factors associated with achieving these outcomes.

Methods: This is a retrospective study with prospectively collected data. Patient-reported outcome measures (PROMs) were collected from April 2017 to March 2020. All patients who underwent arthroscopic meniscal repair and completed both preoperative and postoperative PROMs were included in the analysis. MCID and PASS were calculated via half the standard deviation of the delta PRO change from baseline (for International Knee Documentation Committee Score [IKDC]) and via anchor-based methodology (Knee Injury and Osteoarthritis Outcome Score [KOOS] subscales).

Results: Sixty patients were included in the final analysis. The established MCID threshold values were 10.9 for IKDC, 12.3 for KOOS Symptoms, 11.8 for KOOS Pain, 11.4 for KOOS Activities of Daily Living (ADL), 16.7 for KOOS Sport, and 16.9 for KOOS Quality of Life (QoL). Postoperative scores greater than the following values corresponded to the PASS: 69.0 for IKDC, 75.0 for KOOS Symptoms, 80.6 for KOOS Pain, 92.7 for KOOS ADL, 80.0 for KOOS Sport, and 56.3 for KOOS QoL. Higher preoperative PRO scores were associated with lower likelihood of achieving MCID. Concomitant ligament procedures were associated with a higher likelihood of achieving PASS. Tears to both menisci were associated with decreased likelihood of achieving MCID and PASS for IKDC. Horizontal tears were associated with decreased likelihood of achieving PASS for IKDC and KOOS. Complex tears were associated with decreased likelihood of achieving MCID for KOOS.

Conclusion: Clinically meaningful outcomes such as MCID and PASS were established for meniscal repair surgery using selected PROMs for IKDC and KOOS subscales. Variables more likely to be associated with achieving these outcomes include lower preoperative PRO score and concomitant ligament procedure, whereas higher preoperative PRO score, tearing of both medial and lateral menisci, and horizontal and complex tear classifications were associated with decreased likelihood of achieving these outcomes.

Level of evidence: IV, retrospective case series.