American Board of Surgical Assistants (ABSA) Orthopedic Practice Test

In the differential diagnosis of fracture versus dislocation, which clinical sign is NOT present with dislocation?

1. Point tenderness

2. Deformity

3. Local swelling

4. Crepitus

The correct answer is: Crepitus

When considering the differential diagnosis between a fracture and a dislocation, the presence of certain clinical signs can help differentiate the two. In the case of a dislocation, crepitus, which refers to the grating or cracking sound produced by bone fragments moving against each other, is typically not present. This is primarily because a dislocation involves the displacement of bones at a joint without the continuity of the bone being broken. Point tenderness, deformity, and local swelling are all signs more commonly associated with dislocations as they indicate that there is an abnormal positioning of the joint and associated soft tissue inflammation. Point tenderness occurs due to the stress and trauma on the surrounding ligaments and cartilage. Deformity often becomes apparent upon inspection, as the joint may appear misaligned. Local swelling can result from the body's inflammatory response to the injury. In contrast, crepitus is more characteristic of fractures where there is actual bone fracture, causing the ends of the broken bone to rub against each other or other structures within the joint space. Therefore, the absence of crepitus is a key distinguishing feature in dislocations compared to fractures.