**Core Concept**
A Colles' fracture is characterized by a displacement of the distal radius and ulna in the forearm, resulting from a fall onto an outstretched hand. This type of fracture is common in elderly individuals due to osteoporosis and decreased bone density.

**Why the Correct Answer is Right**
In a Colles' fracture, the distal radial metaphysis is displaced dorsally due to the collapse of the bone under the compressive force exerted during the fall. This displacement occurs because the dorsal aspect of the radius is subjected to a greater force than the palmar aspect. The distal ulna is also involved in the fracture, leading to a characteristic dorsal angulation of the distal forearm. The displacement of the distal radial metaphysis is a key feature of Colles' fracture, which can be confirmed through radiographic imaging.

**Why Each Wrong Option is Incorrect**
**Option A:** The fall typically occurs on the palmar aspect of the wrist, leading to a fracture of the radius and ulna. A fall on the dorsum of the wrist is more likely to result in a scaphoid fracture.
**Option B:** Open reduction is generally not the most common treatment for Colles' fracture, especially in elderly patients. Closed reduction and casting or percutaneous pinning are often preferred due to the risks associated with surgery in older adults.
**Option C:** Colles' fracture is more common in elderly women, particularly those with osteoporosis, rather than younger men. The increased bone density and muscular strength in younger men make them less susceptible to this type of fracture.

**Clinical Pearl / High-Yield Fact**
A Colles' fracture should be suspected in any elderly individual presenting with a deformity of the forearm and wrist after a fall. Prompt radiographic imaging can confirm the diagnosis and guide treatment.

**✓ Correct Answer: D. The distal radial metaphysis is displaced dorsally.**