Diagnostic accuracy of five orthopedic clinical tests for diagnosis of superior labrum anterior posterior (SLAP) lesions
Cook C, Beaty S, Kissenberth MJ, Siffri P, Pill SG, Hawkins RJ. J Shoulder Elbow Surg. 2012 Jan;21(1):13-22. Epub 2011 Oct 28.
Superior labrum anterior to posterior (SLAP) lesions are common among overhead athletes (e.g., baseball, softball, swimming, tennis, volleyball, and javelin) and require surgical intervention to eliminate symptoms and improve function. However, clinically diagnosing SLAP lesions are often difficult due to several factors; including the lack of special tests that are both specific and sensitive. Therefore, the purpose of this study was to evaluate the diagnostic accuracy of 5 clinically used special tests and clusters of tests for SLAP lesions. Cook et al. examined 87 continuous shoulder patients that consented to shoulder arthroscopy. Five special tests were performed on all patients (Active compression/O’Brien’s test, Biceps Load II test/Kim II, Dynamic Labral Shear test, Speed’s test, and Labral Tension test). All patients also completed the DASH questionnaire to assess upper extremity pain and function. SLAP lesions were confirmed during shoulder arthroscopy and included type I, II, and IV. Patients were identified as having no SLAP lesion but other shoulder pathology or having SLAP lesions. Patients with SLAP lesions were further sub-divided into SLAP with and without secondary injury. The results were calculated to evaluate the diagnostic performance of the special tests (sensitivity, specificity, positive and negative predictive values [PPV and NPV], and positive and negative likelihood ratios) for identifying the SLAP only (without secondary injury) group and the SLAP with and without secondary injury (55 patients). A PPV assesses the ability of the test to be positive when the injury is present. A NPV assesses the ability of the test to be negative when the injury is not present. A perfect test would have a PPV and NPV value of 100%. Based on the SLAP-only group, they found that all special tests performed poorly. The Biceps Load II test had moderate sensitivity and specificity and a PPV of 19% and a NPV of 90%. The Labral Tension test had low sensitivity and high specificity with a PPV of 19% and a NPV of 90%. Dynamic Labral Shear had a high sensitivity and low specificity with a PPV of 16% and NPV of 93%. The Active Compression test had a high sensitivity and a low specificity with a PPV of 15% and a NPV of 78%. The Speed’s test had moderate sensitivity and specificity with a PPV of 14% and a NPV of 88%. There were no improvements in outcomes with SLAP lesions with and without secondary injuries or when the 5 special tests were combined together.
The results of this study examined several commonly used clinical tests for SLAP lesions but did not find a test which can be used to accurately to diagnose a SLAP lesion. This is an ongoing problem with the clinical diagnosis of SLAP lesions. Based on the results it seems that some tests have high sensitivity while others have high specificity (a.k.a, some over diagnose and other under diagnose) but none having both. This would suggest that combining these tests together would create a series of tests to accurately diagnosis SLAP lesions; however, this was not demonstrated. The combination of tests did not improve the diagnostic accuracy. Clearly shoulder injuries are complex and are more difficult to diagnose compared to other joints; however, there are other ways to improve accuracy. This study and others don’t have the ability to include a complete history and other aspects of the clinical exam which are large components to improving our ability to accurately diagnosis. With the addition of these components it is possible the accuracy of diagnosing SLAP lesions would improve. In addition, I feel that the special test for diagnosing a SLAP lesion needs to replicate the mechanism of injury. For example if you are an overhead athlete then a special test that positions the patient in the throwing position would improve the accuracy. What is your experience with these special tests? Do you use a cluster of tests? Have you tried using tests to replicate the mechanism of injury?
Written by: Stephen Thomas
Cook C, Beaty S, Kissenberth MJ, Siffri P, Pill SG, & Hawkins RJ (2012). Diagnostic accuracy of five orthopedic clinical tests for diagnosis of superior labrum anterior posterior (SLAP) lesions. Journal of Shoulder and Elbow Surgery, 21 (1), 13-22 PMID: 22036538