Validation of a novel magnetic resonance imaging classification and recommended treatment for lateral elbow tendinopathy

Background Lateral epicondylitis is one of the most common upper extremity problems presented to orthopedic surgeons. Despite a rapid and accurate arrival at a diagnosis by clinical examination, there exists no consensus classification for this condition, which hampers clinical approaches for treatment of the disease based on its severity. Thus, the aim of this study was to propose and valiadate a new magnetic resonance imaging (MRI) classification of lateral epicondylitis, staging by tendinosis, the degree of thickness tears of the common extensor tendon (CET) and bone bruise lesion. Method MRI assessment of the elbow of 75 patients (57 women and 18 men; mean age:51.4 years (range,34-73) from Jan 2014 to Jan 2021 who were diagnosed with lateral epicondylitis were included in the study. MR images were reviewed retrospectively by two independent upper extremities orthopedists and one musculoskeletal radiologist. Inter- and intra-observer reliabilities for the classification were calculated using kappa statistics for the analysis of interrater agreement. Correlation between the stage of the disease and the duration of symptom before MRI was calculated using Kruskal-wallis test. Results Various degrees of CET lesions were demonstrated in this population (Stage I-17, IIA-7, IIB-22 and III-29). Intra-observer agreements of MRI staging were substantial to satisfactory. Inter-observer agreements were moderate to substantial. There was no significant correlation between the disease stage and the patient age or the duration of symptom before MRI. Conclusion Our MRI classification has emerged as one of the most reliable methods to define stages of chronic lateral epicondylitis. At the end, we have suggeted a clearer direction for understanding the disease pathology as well as an appropriate management protocol for each stage of the disease in line with the recent body of literature.

Automated summary

This study proposed and validated a new MRI classification for chronic lateral epicondylitis, showing high reliability and no significant correlation between disease stage and patient age or symptom duration.