Defining clinically relevant outcome thresholds for pain and function after osteochondral autograft transplantation of the knee.

Abstract

To define the minimal clinically important difference (MCID) for measures of pain and function at 2, 5 and 10 years after osteochondral autograft transplantations (OATs). Patients undergoing OATs of the knee were identified from a prospectively maintained cartilage surgery registry. Baseline demographic, injury and surgical factors were collected. Patient-reported outcome scores (PROMs) were collected at baseline, 2-, 5- and 10-year follow-up, including the International Knee Documentation Committee (IKDC) score, Knee Outcome Survey Activities of Daily Living Scale (KOS-ADLS), Marx activity scale and Visual Analogue Scale (VAS) for pain. The MCIDs were quantified for each metric utilizing a distribution-based method equivalent to one-half the standard deviation of the mean change in outcome score. The percentage of patients achieving MCID as a function of time was assessed. Of 63 consecutive patients who underwent OATs, 47 (74.6%) patients were eligible for follow-up (surgical date before October 2021) and had fully completed preoperative PROMs. A total of 39 patients (83%) were available for a minimum 2-year follow-up, with a mean (±standard deviation) follow-up of 5.8 ± 3.4 years. The MCIDs were determined to be 9.3 for IKDC, 2.5 for Marx, 7.4 for KOS-ADLS and 12.9 for pain. At 2 years, 78.1% of patients achieved MCID for IKDC, 77.8% for Marx, 75% for KOS-ADLS and 57.9% for pain. These results were generally maintained through 10-year follow-ups, with 75% of patients achieving MCID for IKDC, 80% for Marx, 80% for KOS-ADLS and 69.8% for pain. The majority of patients achieved a clinically relevant outcome improvement after OATs of the knee, with results sustained through 10-year follow-up. Patients who experience clinically relevant outcome improvement after OATs in the short term continue to experience sustained benefits at longer-term follow-up. These data provide valuable prognostic information when discussing patient candidacy and the expected trajectory of recovery. Level III.