## **Core Concept**
The carrying angle, also known as the cubitus angle, is the angle between the long axis of the humerus and the forearm when the arm is fully extended in supination. It averages about 5-15 degrees in adults and helps to avoid the medial epicondyle of the humerus from hitting the lateral epicondyle of the opposite forearm when moving the arm. Alterations in this angle can indicate specific types of elbow deformities.

## **Why the Correct Answer is Right**
A decrease in the carrying angle results in a cubitus varus deformity, also known as a "gunstock deformity." This condition often occurs after a supracondylar fracture of the humerus that hasn't been properly aligned during healing. The deformity leads to a reduced carrying angle, making the arm appear more straight than normal when extended.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option would typically represent an increased carrying angle, known as cubitus valgus. This condition can result from a lateral condylar fracture of the humerus or from certain types of fractures around the elbow that lead to overgrowth of the lateral condyle.
- **Option B:** This would not specifically relate to a change in the carrying angle but could represent other types of elbow deformities not directly associated with alterations in the carrying angle.
- **Option C:** Similarly, this option does not directly relate to a decrease or increase in the carrying angle and could represent various other elbow or forearm deformities.

## **Clinical Pearl / High-Yield Fact**
A classic clinical scenario to remember is that a "gunstock deformity" or cubitus varus is a common complication of a supracondylar fracture of the humerus, especially if the fracture is not adequately reduced. This deformity results in a decreased carrying angle.

## **Correct Answer:** . Cubitus varus (gunstock deformity)