The Porcellini test: a novel test for accurate diagnosis of posterior labral tears of the shoulder: comparative analysis with the established tests.

Questions/purposes: Although the posterior labral tears of the shoulder are known for their disabling clinical course, especially in overhead athletes, no clinical test used in isolation can diagnose it accurately in the preoperative period. We wanted to: (1) introduce "Porcellini test" with its radiological verification furnishing the anatomical basis of its mechanism; (2) determine its accuracy; and (3) compare its accuracy with that of the other established tests for diagnosing posterior labral tears of the shoulder.

Methods: To determine the anatomical basis, we initially performed radiological verification of our test. Then, we evaluated its accuracy in a retrospective case-controlled study on 310 consecutive patients who underwent shoulder arthroscopic procedures at our hospital between January 2013 and December 2013. All patients were examined preoperatively for Porcellini test, and the presence of posterior labral tear was confirmed on arthroscopy. Later, in a cohort study on 91 consecutive patients who underwent shoulder arthroscopic procedures, we compared its accuracy with O'Brien's test, the Kim test, the Jerk test, and the Load and Shift test. The accuracy was interpreted in terms of sensitivity, specificity, and predictive values.

Results: The radiological verification conferred the anatomical basis for the mechanism of the Porcellini test. This new test showed high accuracy for posterior labral tears with sensitivity of 100 %, specificity of 99.3 %, the positive and negative predictive values of 92.6 and 100 %, respectively. Also, it had superior accuracy results than every other test. The interexaminer reliability for all test results was found to be >0.80.

Conclusions: We propose "Porcellini test" as a simple, accurate, reproducible, and reliable test for the preoperative diagnosis of posterior labral tears of shoulder.