Most cases of slipped capital femoral epiphysis (SCFE) present with chronic pain while a few present acutely. Studies have suggested a structural weakness in the capital femoral physis during the onset of puberty. SCFE occurs predominantly in children (9 to 15 of age) with a male/female predominance of approximately 2:1. The obese are particularly susceptible.
The diagnosis of SCFE should be considered in any preadolescent or adolescent complaining of hip, thigh or knee pain. The history is one of minimal trauma, causing pain in the hip, thigh or knee region. Vague or diffuse hip or knee pain and a limp in the preceding weeks are also common.
At rest, the patient may lie with the hip slightly flexed with some external rotation. Range of motion (ROM) abnormalities of the hip, in particular, limitation of internal rotation, abduction and flexion are almost universal. ROM in all directions may be painful.
The diagnosis is made by physical and radiographic examination (anteroposterior and lateral hip (or ‘frog leg’) views). The affected femoral head is displaced inferior to the femoral neck.
Legg-Calve-Perthes disease (LCPD) is a hip disorder involving the avascular necrosis of the capital femoral epiphysis that generally has an onset between the ages of 4 and 9 years. Males outnumber females by a ratio of 4:1 and most children with LCPD are short with delayed bone age.
The onset of LCPD is usually insidious. Presentation as an acute emergency is rare. Mild hip pain and a limp may be present for weeks or months before diagnosis. Pain is often referred in the distribution of the obturator nerve to the knee, anteromedial thigh or groin. Physical findings include decreased hip abduction and internal rotation. Thigh muscle atrophy may be noted.
At the early stages, radiographs show a widening of the articular cartilage with a small, dense proximal femoral epiphysis. Subchondral fracture may be visible (see Fig. 1). Irregularity and flattening of the epiphysis develop over time. Other differential diagnoses for LCPD include various types of bone tumors and skeletal dysplasias.
Management is a team effort and may require a pediatric orthopedist who will follow and treat the child through the various stages of the disease. Older children, obese patients, girls and those with more severe disturbance of the epiphysis on radiographs have a poorer prognosis.
Fig. 1. A radiograph showing a normal hip and a hip with LCPD
Reference 1: Fleisher G R, Ludwig S, Baskin M N. Atlas of Pediatric Emergency Medicine. 2004. Lippincott Williams & Wilkins Publishers. Section 1: Medical and Surgical Emergencies. Chapter 12, Musculoskeletal Emergencies. Pg 224.