Background Detection of a posteroinferior labral lesion by physical examination is often difficult. Purpose To introduce a novel diagnostic test for detecting a posteroinferior labral lesion of the shoulder. Hypothesis The Kim test can detect a posteroinferior labral lesion of the shoulder. Study Design Cohort study (diagnosis); Level of evidence, 1. Methods In 172 painful shoulders, the Kim test was compared with the jerk test and was verified by arthroscopic examination. A sudden onset of posterior shoulder pain and click with or without clunk indicated a positive test result. Results Thirty-three shoulders had a positive Kim test result, in which 24 had a posteroinferior labral lesion and 9 had a normal posteroinferior labrum. Of 139 shoulders with a negative Kim test result, 6 had a posteroinferior labral tear and 133 had a normal posteroinferior labrum. The sensitivity of the Kim test was 80%, specificity was 94%, positive predictive value was 0.73, and negative predictive value was 0.96. The interexaminer reliability between 2 examiners was 0.91. The accuracy of the jerk test in detecting a posteroinferior labral lesion was the following: sensitivity, 73%; specificity, 98%; positive predictive value, 0.88; and negative predictive value, 0.95. The location of the posterior labral lesion was predominantly posterior in 19 shoulders and predominantly inferior in 11 shoulders. The Kim test was more sensitive in detecting a predominantly inferior labral lesion, whereas the jerk test was more sensitive in detecting a predominantly posterior labral lesion. The sensitivity in detecting a posteroinferior labral lesion increased to 97% when the 2 tests were combined. Conclusion The Kim test is a reliable diagnostic test for detection of a posteroinferior labral lesion.

BACKGROUND:The jerk test has been used as a diagnostic test of the posteroinferior instability of the shoulder. Pain may or may not be associated with posterior clunking during the jerk test.PURPOSE:To evaluate the presence or absence of pain with the jerk test as a predictor of the success of nonoperative treatment for posteroinferior instability of the shoulder and to identify the pathologic lesion responsible for the pain in the jerk test.STUDY DESIGN:Retrospective review of prospectively collected data.METHODS:Eighty-one patients (89 shoulders) who had posteroinferior instability with a positive posterior clunk in their shoulders during the jerk test were nonoperatively treated. The patients were divided into 2 groups with respect to the presence of pain in the jerk test: the painless jerk group (54 shoulders) and the painful jerk group (35 shoulders). Response to the nonoperative treatment was evaluated after at least a 6-month rehabilitation program. Patients who did not respond to the rehabilitation underwent arthroscopic examination to identify any pathologic lesions.RESULTS:The painful jerk group had a higher failure rate with nonoperative treatment (P < .001). In the painless jerk group, 50 shoulders (93%) responded to the rehabilitation program after a mean of 4 months. Four shoulders (7%) were unresponsive to the rehabilitation. In the painful jerk group, 5 shoulders (16%) were successful with the rehabilitation, whereas the other 30 shoulders (84%) failed. All 34 shoulders that were unresponsive to the rehabilitation had a variable degree of posteroinferior labral lesions.CONCLUSIONS:The jerk test is a hallmark for predicting the prognosis of nonoperative treatment for posteroinferior instability. Shoulders with symptomatic posteroinferior instability and a painful jerk test have posteroinferior labral lesions.