The crank test, the O'Brien test, and routine magnetic resonance imaging scans in the diagnosis of labral tears

Abstract

Background: Tears of the superior labrum of the shoulder, anterior to posterior, are difficult to diagnose clinically.

Purpose: We examined whether the crank or O'Brien tests were reliable tools for detecting glenoid labral tears.

Study design: Nonrandomized prospective study.

Methods: Results of diagnostic shoulder arthroscopy were compared with those of the preoperative tests and magnetic resonance imaging for 65 patients who had symptoms of shoulder pain.

Results: The crank test result was positive in 29 patients (45%), and the O'Brien test was positive in 41 patients (63%). The crank test had a positive predictive value of 41%, was 56% specific, 46% sensitive, and had a negative predictive value of 61%. The O'Brien test had a positive predictive value of 34%, was 31% specific, 54% sensitive, and had a negative predictive value of 50%. Magnetic resonance imaging had a positive predictive value of 63%, was 92% specific, 42% sensitive, and had a negative predictive value of 83%.

Conclusions: The O'Brien and crank tests were not sensitive clinical indicators for detecting glenoid labral tears and other tears of the anterior and posterior labrum. Results were often falsely positive for patients with other shoulder conditions, including impingement or rotator cuff tears.