An 8 year old boy with a history of fall from 10 feet height complains of pain in the right ankle. X-ray taken at that time are normal without any fracture line. But after 2 years, he developed a calcaneovalgus deformity. The diagnosis is:

**Core Concept**
The underlying condition in this case is a type of injury that occurs when there's an excessive stretching or tearing of the ligaments, typically seen in young children after a fall. This condition often leads to a deformity in the affected joint.

**Why the Correct Answer is Right**
The boy's symptoms and progression suggest a diagnosis of **Juvenile Osteochondritis Dissecans (JOCD)**. JOCD occurs when a piece of cartilage and bone becomes separated from the surrounding bone due to inadequate blood supply. This can happen after a traumatic event, like a fall, and may not be immediately visible on X-rays. Over time, the affected area may undergo necrosis and lead to degenerative changes, resulting in a deformity like calcaneovalgus.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not relevant to the given scenario.
* **Option B:** This option is incorrect as it doesn't match the described symptoms and progression of the condition.
* **Option C:** This option is not applicable to the given case history.

**Clinical Pearl / High-Yield Fact**
In children, it's essential to differentiate between a fracture and a soft tissue injury, as the latter might not be immediately apparent on X-rays. A thorough clinical evaluation and follow-up are crucial in diagnosing conditions like JOCD.

**Correct Answer:** C.

✓ Correct Answer: C. Tibial epiphyseal injury