Overview
This video reviews Elson’s Test and a simple modification for diagnosing central slip injuries of the extensor tendon at the proximal interphalangeal (PIP) joint, highlighting key clinical signs and potential long-term complications.
Elson’s Test Procedure and Interpretation
- The patient flexes the injured PIP joint to 90 degrees over a table or firm surface.
- The examiner asks the patient to extend the PIP joint against resistance.
- The examiner observes for extension strength at the PIP and abnormal extension at the distal interphalangeal (DIP) joint.
- A positive Elson’s Test is characterized by weak or absent PIP extension combined with fixed DIP extension, indicating central slip rupture.
- Anatomically, central slip injury allows lateral bands to migrate volarly and extend the DIP abnormally.
Modified Elson’s Test (Symmetry Test)
- The patient presses the injured finger against the equivalent finger of the opposite hand.
- When the central slip is intact, the DIP remains semi-flexed and floppy due to restrained lateral bands.
- If injured, asymmetry is seen: the lateral bands migrate, causing DIP extension in the injured finger.
Clinical Significance of Central Slip Injuries
- Prompt detection is critical, especially for emergency and acute care practitioners.
- Missed central slip injuries can later lead to boutonnière deformity, which is challenging to repair surgically.
- Awareness and early diagnosis can prevent long-term dysfunction.
Recommendations / Advice
- Use Elson’s Test and its modification to promptly assess central slip function in hand injuries involving the PIP joint.
- Early identification and intervention are essential to avoid boutonnière deformity and preserve finger function.