If the patient's hook sign shows an intact tendon, is the test considered negative or positive?

Hook Test Interpretation: Intact Tendon = Negative Test

If the hook test shows an intact tendon, the test is NEGATIVE. A negative hook test means you can successfully "hook" your finger under the intact tendon, indicating the tendon is structurally continuous and not completely ruptured 1.

Understanding the Hook Test Mechanics

The hook test is performed with the patient actively supinating while the elbow is flexed to 90 degrees. The examiner attempts to hook their index finger under the biceps tendon from the lateral side 1:

• NEGATIVE (Normal) Test: You CAN hook your finger under a cord-like structure = intact tendon
• POSITIVE (Abnormal) Test: You CANNOT hook your finger under anything = complete rupture

Evidence for Test Interpretation

The original description by O'Driscoll demonstrated that an intact hook test (negative for pathology) permits the examiner to hook their finger under the intact biceps tendon, while an abnormal hook test (positive for pathology) means there is no cord-like structure to hook under 1. This study showed 100% sensitivity and specificity when using this interpretation.

The most recent high-quality prospective study from 2023 confirmed this interpretation, finding 96% sensitivity and 67% specificity for detecting complete distal biceps tendon ruptures 2. The study explicitly used the ability to hook under the tendon as the negative finding.

Clinical Application Algorithm

When performing the hook test:

1. Can hook finger under tendon → Negative test → Tendon likely intact (though may still have partial tear if painful) 1
2. Cannot hook finger under tendon → Positive test → Complete rupture highly likely 3
3. Can hook but causes pain → Technically negative but consider partial tear 1

Important Caveats

• A negative hook test does NOT exclude partial tears - it was only 30% sensitive for partial ruptures 4
• When the lacertus fibrosus remains intact, sensitivity drops to 45%, potentially giving false-negative results 4
• The hook test should not be used in isolation - the 2023 prospective study cautioned against relying on this examination alone due to imperfect specificity (67%) 2
• Combining the hook test with biceps crease interval measurement improves diagnostic accuracy to 94% sensitivity and 100% specificity for acute complete ruptures 3

After successful surgical repair, the hook test result should return to negative (intact/normal) by approximately 10 weeks postoperatively in 89% of cases 5.