Total joint arthroplasty patients who experience the minimal clinically important difference for worsening (MCID-W) have higher revision rates at 1, 3, and 5 years postoperatively:

Abstract

Introduction

The Minimal Clinically Important Difference (MCID) is critical in assessing patient-reported outcomes following total joint arthroplasty (TJA). Although many studies consider the MCID for Improvement (MCID-I), thresholds have also been defined for the MCID for Worsening (MCID-W). However, the potential impact of the MCID-W on surgical outcomes in TJA is under-investigated. This study investigated the association between the MCID-W and revision rate.

Materials and methods

This retrospective study was performed using 2787 primary TJAs—1563 total knee arthroplasties (TKAs) and 1224 total hip arthroplasties (THAs)—with minimum five-year follow-up. Patient-Reported Outcomes Measurement Information System Physical Function Short Form 10a (PROMIS PF-10a) scores were collected preoperatively and at one-year postoperatively. Patients were classified based on experiencing MCID-I, MCID-W, or “no change” after TJA (scores between MCID-I and MCID-W). MCID-W and MCID-I values were determined by a distribution-based method. Revision-free survival was compared at 1 year, 3 years, and 5 years postoperatively.

Results

The overall revision rate for the entire TJA cohort was 1.1% at 1 year, 1.8% at 3 years, and 2.2% at 5 years postoperatively. TJA patients who experienced MCID-W had a higher revision rate than MCID-I patients at 1 year (3.6 versus 0.8%, P < 0.001), 3 years (5.3 versus 1.1%, P < 0.001), and 5 years postoperatively (5.7 versus 1.5%, P < 0.001). Similarly, stratifying into TKAs and THAs revealed an association between MCID-W and higher revision rates. Revision-free survival curves for MCID-W patients revealed lower survival at 1 year (P < 0.001), 3 years (P < 0.001), and 5 years (P < 0.001).

Conclusions

Patients experiencing the MCID-W are more likely to undergo revision surgery at 1, 3, and 5 years following both THA and TKA procedures. The MCID-W may be a useful tool to help identify postoperative THA and TKA patients at highest risk for revision surgery. Future studies utilizing MCID-W as a predictive tool are needed to determine its effectiveness in optimizing TJA patient outcomes.