Certified Hand Therapist (CHT) Practice Exam

How do you test the stability of PIP collateral ligaments after a dislocation?

1. Active flexion and extension of the finger

2. Passive lateral stress in full extension and flexion

3. Palpation of the ligaments

4. X-ray imaging

The correct answer is: Passive lateral stress in full extension and flexion

Testing the stability of the proximal interphalangeal (PIP) collateral ligaments after a dislocation is critical for determining the integrity of these structures. The method that involves passive lateral stress in both full extension and flexion of the finger is effective because it allows for an assessment of the ligament's ability to stabilize the joint under different positional loads. In full extension, the PIP joint is subjected to maximum tension on the collateral ligaments, which helps in identifying instability. If the ligaments are compromised, applying a lateral stress can reveal excessive translation or gapping, indicating a failure of the restraint provided by the ligaments. Similarly, performing this test in flexion allows for a different perspective on the ligaments' behavior under a more relaxed tension state. This comprehensive approach ensures that both states of ligament function are evaluated, making it a reliable method for assessing collateral ligament injuries. Other options, while potentially useful in a broader assessment, do not specifically focus on the stability of the collateral ligaments. Active flexion and extension measure overall joint range but do not isolate ligament stability. Palpation of the ligaments can provide some information about tenderness or thickening but lacks the dynamic assessment of ligament integrity under stress. X-ray imaging might show fractures or