Introduction

The ability to predict meniscal tear reparability based on pre-operative MRI is desirable for post-operative planning, however, the accuracy of predictive methods varies widely within the orthopedic and radiology literature. We set out to determine if the higher resolution offered by 3-Tesla (3T) MRI improves the accuracy and reliability of previously described reparability prediction methods. In addition, we sought to compare the results of these previously described methods to new meniscus tear reparability prediction methods based upon the most influential imaging parameters identified in our study population.

Methods

We retrospectively identified 44 patients age 16 to 40 years who were known to have undergone arthroscopic meniscus repair at our institution between the dates of January 1, 2013 and June 1, 2019. This cohort was then matched by age, gender and BMI with 43 patients who underwent arthroscopic meniscectomy during the same time period. Preoperative 3T MR images from all 87 patients were independently and blindly reviewed by two fellowship-trained musculoskeletal radiologists and two orthopedic surgeons with fellowship training in sports medicine. For each meniscus tear, reviewers evaluated the following criteria: tear pattern, tear length, tear distance from menisco-capsular junction, tear thickness, and the integrity of any inner meniscal fragment. The resultant data was then applied to 5 different methods for predicting meniscus tear reparability. Inter-rater reliability and meniscus repair prediction accuracy were subsequently evaluated and compared between each of these 5 prediction methods. Inter-rater reliability and independent predictive value were also examined for individual imaging criteria.

Results

Accuracy for all examined prediction methods was poor, ranging from 55% (Three-Point method) to 72% (Classification Tree method) among all reviewers. Accuracy was largely similar between radiologists and surgeons, without significant differences in performance as a whole. With regard to the examined imaging criteria, only Tear Pattern (p = 0.025) and Junction Distance (p = 0.028) among radiologist reviewers were found to have a significant association with surgical repair. Among surgeon reviewers, Tear Pattern reached borderline statistical significance (p = 0.050). Inter-observer reliability, however, was poor for all of the examined imaging criteria, with kappa values ranging from 0.07 (Inner Fragment Status) to 0.40 (Tear Pattern).

Conclusion

MR imaging continues to be a poor predictor of meniscus tear reparability as assessed by arthroscopic criteria, even when using higher resolution 3T scanners. Inter-observer reliability in this setting can be poor even among experienced clinicians. Arthroscopic inspection remains the gold standard for the determination of meniscus tear reparability.