A 56-year-old woman visits the emergency department after falling on wet pavement. Radiographic examination reveals osteoporosis and a Colles’ fracture. Which of the following carpal bones are often fractured or dislocated with a Colles’ fracture?

**Core Concept**
The Colles' fracture is a type of fracture that occurs at the distal end of the radius bone in the forearm, often resulting from a fall onto an outstretched hand. This fracture can lead to instability in the wrist joint, affecting the surrounding carpal bones.

**Why the Correct Answer is Right**
In a Colles' fracture, the distal radius bone is displaced, causing the wrist joint to become unstable. The scaphoid and lunate bones in the proximal row of the carpal bones are often affected due to their articulation with the radius bone. The scaphoid bone is particularly prone to fracture or subluxation (partial dislocation) in this scenario, as it is the most mobile carpal bone and is closely associated with the radius bone. The lunate bone may also be affected due to its articulation with the scaphoid bone.

**Why Each Wrong Option is Incorrect**
* **Option A:** The triquetrum bone is less commonly affected in Colles' fractures, as it is not directly associated with the displaced radius bone.
* **Option B:** The pisiform bone is not typically involved in Colles' fractures, as it is a small sesamoid bone embedded within the flexor carpi ulnaris tendon.
* **Option D:** The capitate bone is not directly associated with the radius bone and is therefore less likely to be affected in a Colles' fracture.

**Clinical Pearl / High-Yield Fact**
In patients with Colles' fractures, it is essential to carefully assess the scaphoid and lunate bones for any signs of fracture or subluxation, as these injuries can lead to long-term wrist instability and arthritis.

**Correct Answer:** C.

✓ Correct Answer: C. Scaphoid and lunate