RE-EVALUATION OF THE DIAGNOSTIC ACCURACY OF MRI IN DETECTION OF ROTATOR CUFF TEAR IN CORRELATION WITH SURGERY.

Abstract Introduction: Rotator cuff tear (RCT) is one of the most common causes of shoulder pain and limitation of shoulder movements for which a patient presents to the clinic. MRI is the first choice of investigation for RCT but the accuracy of MRI in detection of Partial tendon tear(PTT) is still a topic of debate among researchers. Objective: The objective of this study is to re-evaluate the diagnostic efficacy of MRI for the detection of PTT and FTT using surgical finding as the ‘gold standard ‘ by improving the limitations of previous studies. Methods: All patients between January 2012 to January 2017 were preoperatively evaluated by means of complete orthopedic history, physical examination and MRI of the affected shoulder.The initial inspection of all the data only included 110 patients who had both MRI of the affected shoulder joints and subsequent surgery. Among them 13 patients were excluded as they did not undergo either arthroscopic or open surgery. In addition to that 4 more patients were excluded because of a time interval between MRI and surgery exceeded 2 months. The final study group consisted of 93 shoulders from 93 cases (63 female and 30 male) with the mean age of 56.85 years and range of 19 to 83 years. Kappa coefficient test was used to calculated the agreement between the MRI and surgical findings. A P-value less than 0.05 was considered statistically significant. Sensitivity, specificity, accuracy, the positive predictive value and the negative predictive value were calculated based on the cross tables. Results: MRI was able to correctly identify full thickness tear in 9 out of 10 patients with sensitivity, specificity, positive predictive value and negative predictive value of 90.0%, 100%, 100%, 98.9% and partial thickness tear in 70 out of 78 cases with sensitivity, specificity, positive predictive value and negative predictive value of 89.7%, 60%, 92.1%, 52.9% respectively. The accuracy for detection of FTT was 98.9% and PTT was 84.9% and the p value for both tears (FTT and PTT) was less than 0.05. There was a moderate agreement between MRI and surgery for PTT with k value of 0.472 and excellent agreement for FTT with k value of 0.94 . Conclusion: MRI has high accuracy, sensitivity and positive predictive value in diagnosis of both PTT and FTT and also provides an additional information about tendon, muscle and labrum, all of which are pivotal in better management of tear and improving the prognosis.