A 20-years old male presents with anterior shoulder dislocation. This injury is usually caused as a combination of which of the following?
**Core Concept**
Anterior shoulder dislocation occurs due to a combination of factors affecting the glenohumeral joint, leading to the humerus being displaced anteriorly out of the glenoid fossa. This typically involves a combination of external rotation, abduction, and forceful traction on the arm.
**Why the Correct Answer is Right**
The mechanism of anterior shoulder dislocation involves a combination of external rotation, abduction, and forceful traction on the arm, which leads to the humeral head being displaced anteriorly out of the glenoid fossa. This is often seen in sports-related injuries or falls onto an outstretched hand. The external rotation and abduction of the arm cause the humerus to be displaced anteriorly, while the forceful traction on the arm exacerbates the injury.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as internal rotation and adduction would typically lead to posterior shoulder dislocation, not anterior.
**Option B:** While forceful traction on the arm can contribute to the injury, it is not the primary mechanism of anterior shoulder dislocation.
**Option C:** Abduction and internal rotation would not lead to anterior shoulder dislocation; instead, it would be more consistent with a posterior dislocation.
**Clinical Pearl / High-Yield Fact**
Remember the "ABCD" mechanism of anterior shoulder dislocation: Abduction, External Rotation, Compression, and Distracting force (AERCD), which helps to recall the typical sequence of events leading to this injury.
**Correct Answer:** C.