True about slipped femoral capital epiphysis is:
**Core Concept**
Slipped femoral capital epiphysis (SCFE) is a condition where the femoral head slips posteriorly and inferiorly through the growth plate, leading to an unstable hip joint. This condition typically affects adolescents during the pubertal growth spurt, with a peak incidence between 10-15 years of age.
**Why the Correct Answer is Right**
The pathophysiology of SCFE is related to the altered stress distribution across the growth plate, leading to a posterior and inferior displacement of the femoral head. This displacement occurs due to the increased growth rate and weight-bearing demands on the immature hip joint, which can cause the growth plate to become weakened and eventually fracture. The growth plate's weakest point, the area of the growth plate closest to the metaphysis, is where the slip most commonly occurs.
**Why Each Wrong Option is Incorrect**
**Option A:** SCFE is not typically associated with a traumatic event. While trauma can precipitate a SCFE, the condition is often asymptomatic until the slip occurs, and the symptoms are usually gradual in onset.
**Option B:** The primary cause of SCFE is not a mechanical issue, such as a hip flexion contracture. While muscle imbalances and hip flexion contractures may contribute to the development of SCFE, they are not the primary cause.
**Option C:** SCFE does not typically present with a palpable "click" or "snap" at the hip. The diagnosis of SCFE is often made on the basis of radiographic findings, such as a displaced growth plate and an abnormal femoral head position.
**Clinical Pearl / High-Yield Fact**
In SCFE, the affected hip is often held in a flexed, abducted, and externally rotated position, which can help to stabilize the joint and prevent further displacement.
**Correct Answer:** D.