March fracture involves
**Core Concept**
March fracture is a type of stress fracture that occurs in the lower leg bones, particularly in the metatarsals or tibia. It is usually caused by repetitive stress or overuse, often due to activities that involve running or jumping.
**Why the Correct Answer is Right**
The correct answer is related to the pathophysiology of March fracture, which involves microfractures in the bone caused by repeated stress. This can lead to bone fatigue and eventually, a complete fracture. The bones most commonly affected are the second and third metatarsals, due to their role in weight-bearing and the distribution of forces during activities like running.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because March fracture is a specific type of stress fracture, and this option does not accurately describe the condition.
**Option B:** This option is incorrect because while stress fractures can occur in the tibia, March fracture specifically refers to the metatarsals.
**Option C:** This option is incorrect because March fracture is not caused by a single traumatic event, but rather by repetitive stress or overuse.
**Clinical Pearl / High-Yield Fact**
To remember the bones commonly affected by March fracture, recall the "2-3-4" rule: the second and third metatarsals are most commonly affected, and rarely, the fourth metatarsal may be involved.
**Correct Answer: B. Stress fracture in the tibia.**