"Patients with an unstable slip present similarly to those with an acute femoral fracture and are unable to bear weight on the affected limb. A patient with a stable slip can tolerate weight bearing. It's important to understand that this refers to clinical presentation, but even if the patient is initially able to bear weight, they are at risk of evolving to an acute displacement if bed rest is not established 10."
"In the pre-slip phase, there is a widening of the growth plate with irregularity and blurring of the physeal edges and demineralisation of the metaphysis. This is followed by the acute slip, which is posteromedial. In a chronic slip, the physis becomes sclerotic, and the metaphysis widens (coxa magna)."
"femoroacetabular impingement: occurs in some patients who have a residual hip deformity post-correction, characterised by relative posterior and medial displacement of the capital femoral epiphysis, which then leads to an anterolateral prominence of the metaphysis, which abuts the acetabular rim 9"
"Slipped upper femoral epiphysis is more common in boys than girls and occurs at higher rates in Black patients and Hispanic patients than in White patients 4. The age of presentation is somewhat dependent on gender, with boys presenting later (average 13 years, range 10-17 years) than girls (average 11.5 years, range 8-15 years) 2,4. In the USA, the incidence is reported to be ~2.5 per 100,000 children aged 9-16 years 4."
"AP and frog-leg: two-view assessment is common, often done bilaterally as a high number of these injuries are bilateral (as well as the added benefit of comparing to a normal side) 11"
"The slip that occurs is posterior and, to a lesser extent, medial. It is therefore more easily seen on the frog-leg lateral view rather than the AP hip view. Because the epiphysis moves posteriorly, it appears smaller because of projectional factors."
"On the AP, a line drawn up the lateral edge of the femoral neck (line of Klein) fails to intersect the epiphysis during the acute phase (Trethowan sign)."
"The metaphyseal blanch sign, seen on AP views, involves increased density of the proximal metaphysis. It represents the superposition of the femoral neck and the posteriorly displaced capital epiphysis."
"The slip that occurs is posterior and, to a lesser extent, medial. It is therefore more easily seen on the frog-leg lateral view rather than the AP hip view. Because the epiphysis moves posteriorly, it appears smaller because of projectional factors."
Expected headings
"Complications"
"chronic: represents the most common presentation; vague groin and thigh pain for more than 3 weeks, which may progress to a limp"
"Alignment of the epiphysis relative to the femoral metaphysis can be used to grade the degree of slippage; see SUFE grading."