Comprehensive Osteopathic Medical Licensing Examination (COMLEX USA) Practice

What symptoms are indicative of a Grade 3 sprain?

1. Pain with slight movement

2. Complete instability of the joint

3. Localized swelling without instability

4. Severe bruising with minimal swelling

The correct answer is: Complete instability of the joint

A Grade 3 sprain is characterized by a complete tear of the ligament, which results in significant joint instability. This level of sprain typically arises from a forceful injury, leading not only to severe pain but also to an inability to bear weight or use the joint effectively. The complete disruption of the ligament means that the joint lacks the necessary support for normal function, which is the fundamental reason why complete instability is a hallmark symptom. The other options do not appropriately reflect the severity associated with a Grade 3 sprain. For instance, pain with slight movement may indicate a Grade 1 or Grade 2 sprain, where some ligament integrity remains. Localized swelling without instability is more consistent with a minor sprain or strain rather than the complete disruption found in a Grade 3 sprain. Severe bruising with minimal swelling could suggest a different type of injury or a less severe sprain that does not compromise the stability of the joint. Thus, the primary indicator of a Grade 3 sprain is the complete instability of the joint, highlighting the injury's severity and impact on function.