**Question:** An 8-year-old boy had a fall from 10 feet and experienced pain in the right ankle. His initial X-ray was normal. However, after 2 years, he developed a calcaneovalgus deformity. What is the likely diagnosis?

**Core Concept:** Ankle injuries, delayed presentations, and delayed radiographic findings.

**Why the Correct Answer is Right:** In this case, the patient presents with a history of a fall from a height and develops pain in the right ankle. Initially, the X-ray appears normal, which is a typical scenario in pediatric ankle injuries, where soft-tissue injuries often precede bony injuries. Over time, the patient develops a calcaneovalgus deformity, a condition characterized by an excessive eversion and external rotation of the hindfoot, often resulting from a high-energy injury. The delayed presentation and radiographic findings align with the diagnosis of a displaced fracture or a severe ankle sprain that went unnoticed initially.

**Why Each Wrong Option is Incorrect:**

A. **Option A:** This option is incorrect as the patient's initial X-ray was normal, ruling out acute fractures or dislocations.

B. **Option B:** Although the patient's symptoms improved temporarily, the development of a calcaneovalgus deformity indicates a more severe injury than a simple sprain. The patient's condition worsens over time, further ruling out a mild ankle sprain as the primary diagnosis.

C. **Option C:** A salter-harris type IV fracture is related to pediatric growth plate injuries, which typically present acutely. In this case, the patient's delayed presentation and normal X-ray exclude this diagnosis.

D. **Option D:** A calcaneovalgus deformity is not a direct consequence of a Salter-Harris type II fracture. Instead, it is a consequence of a severe ankle injury that went unnoticed initially. The patient's delayed presentation and radiological findings do not support this diagnosis.

**Clinical Pearl:** In pediatric patients, delayed presentations of high-energy ankle injuries should raise suspicion for missed or undisplaced fractures. Prompt imaging may be necessary, even if the initial X-ray is normal, to avoid missing critical findings that can lead to long-term complications like calcaneovalgus deformity.