All the following are “head at risk sig (radiological) that correlate positively with results in the outcome of Pehes’ disease except
**Core Concept**
Pehes' disease, also known as Legg-Calve-Perthes disease, is a childhood hip disorder characterized by avascular necrosis of the femoral head. Radiological signs of "head at risk" are crucial in assessing the severity and outcome of the disease.
**Why the Correct Answer is Right**
The correct answer is the radiological sign that does not correlate positively with the outcome of Pehes' disease. In Pehes' disease, the severity and outcome of the disease are closely related to the extent of femoral head involvement. The radiological signs of "head at risk" include:
* **Subchondral lucency (Option B):** This sign indicates the presence of necrosis in the subchondral bone, which is a strong predictor of poor outcome in Pehes' disease.
* **Sclerosis (Option C):** This sign is indicative of reactive bone formation in response to necrosis, which is also associated with a poor outcome.
* **Loss of joint space (Option D):** This sign indicates the progression of the disease, with cartilage destruction and joint space narrowing, which is a poor prognostic sign.
**Why Each Wrong Option is Incorrect**
* **Option A:** Not specified in the question, but based on the options provided, we can infer that it is not a correct answer.
**Clinical Pearl / High-Yield Fact**
In Pehes' disease, the presence of **subchondral lucency** on radiographs is a strong predictor of poor outcome, and early detection and treatment are crucial to prevent long-term complications.
**Correct Answer:** Not specified in the question, as the options are incomplete.