Crank Test | SLAP Lesions

Summary

In this video, the presenter demonstrates how to perform the crank test to diagnose SLAP lesions, which involve shoulder labral tears. The crank test is explained in both sitting and supine positions, where the patient’s shoulder is placed at 160 degrees of elevation, and an axial load is applied with repeated internal and external rotations. A positive result is indicated by clicking, pain, or apprehension. Although the crank test has a weak clinical value in detecting SLAP lesions, with a sensitivity of 46% and specificity of 72%, the video also encourages viewers to explore more accurate tests such as the compression rotation test.

Takeaways

• 😀 The crank test is a diagnostic tool for detecting SLAP lesions in the shoulder.
• 😀 A meta-analysis by Mervich et al. in 2017 revealed that the crank test has a sensitivity of 46% and specificity of 72%.
• 😀 Due to its relatively low sensitivity, the crank test has limited clinical value for detecting SLAP tears.
• 😀 The crank test can be performed with the patient either sitting or lying supine.
• 😀 In the test, the patient's shoulder is elevated to 160 degrees in the scapular plane with the elbow at 90 degrees.
• 😀 The examiner applies an axial load while rotating the shoulder through repeated internal and external rotations.
• 😀 The aim of the test is to replicate the motion that could pinch a torn labrum in the shoulder.
• 😀 The test is considered positive if the patient experiences clicking, pain, or apprehension during the maneuver.
• 😀 The video encourages viewers to explore the most accurate test for SLAP lesions, as per the meta-analysis (compression rotation test).
• 😀 Viewers are also encouraged to like the video, subscribe to the channel, and follow the content on social media platforms.

Q & A

What is the crank test used for?

The crank test is used to diagnose SLAP (Superior Labrum Anterior and Posterior) lesions in the shoulder, helping to identify labral tears.

What were the sensitivity and specificity of the crank test according to the meta-analysis by Mervich et al. (2017)?

The crank test had a sensitivity of 46% and a specificity of 72%, which indicates that it has weak clinical value in detecting SLAP tears.

What is the sensitivity of a medical test?

Sensitivity refers to the test's ability to correctly identify those with the condition (true positive rate). In this case, the crank test correctly identifies 46% of individuals with SLAP lesions.

What is the specificity of a medical test?

Specificity refers to the test's ability to correctly identify those without the condition (true negative rate). The crank test has a specificity of 72%, meaning it can correctly identify 72% of people without SLAP lesions.

How is the crank test performed?

The crank test is performed by positioning the patient's shoulder at 160 degrees of elevation in the scapular plane, flexing the elbow to 90 degrees, and then applying an axial load while rotating the shoulder internally and externally.

What does a positive crank test indicate?

A positive crank test indicates the presence of a SLAP lesion, typically identified by clicking, pain, or apprehension during the test.

Can the crank test be performed in different positions?

Yes, the crank test can be performed with the patient either sitting or lying in a supine position.

What is the role of axial load in the crank test?

The axial load is applied to the shoulder during the crank test to increase pressure on the labrum, potentially causing the torn labrum to pinch and elicit symptoms.

What other shoulder test is recommended as more accurate than the crank test?

The compression-rotation test is recommended as more accurate for diagnosing SLAP lesions, based on the same meta-analysis by Mervich et al. (2017).

What should be done if the crank test results in apprehension or pain?

If the crank test results in apprehension or pain, it may indicate a SLAP lesion, but further diagnostic tests and clinical evaluation are recommended for confirmation.