Legg-Calve-Perthes disease and slipped capital femoral epiphysis: Clinical sciences

Legg-Calvé-Perthes disease, or LCPD, and slipped capital femoral epiphysis, or SCFE for short, are distinct hip conditions that commonly cause limp in children. In LCPD, a disrupted blood supply causes deformation of the femoral head and subsequently leads to osteonecrosis. On the other hand, in SCFE, a weakness of the growth plate causes displacement of the femoral head from the femoral neck. It’s important to identify and treat both of these conditions quickly to ensure better functional outcomes and reduce the risk of hip osteoarthritis. Based on history, exam, and imaging findings, you can differentiate between LCPD and SCFE.

If your patient presents with a chief concern suggesting either LCPD or SCFE, you should first perform a focused history and physical exam. Children with LCPD are usually less than 8 years old and classically present with a painless limp, which is usually unilateral. However, patients with more severe disease may develop a painful limp and could report pain in the hip, as well as the groin, thigh, or knee. LCPD is more common in biologically male children, and there could be a family history of LCPD.

Now here’s a clinical pearl to keep in mind! Whenever a child reports pain in a specific joint, always be sure to examine the joints directly above and below, since pain can refer to adjacent joints. For instance, if a child reports knee pain, you should examine the knee, as well as the hip and ankle.

The physical exam of a child with LCPD will often reveal limited internal rotation and abduction of the affected hip. While your patient is standing or walking, you might notice the Trendelenburg sign, which is a pelvic tilt caused by hip muscle weakness. The hip could also be tender to palpation, and in more severe cases, the affected leg could even be noticeably shorter than the unaffected leg. Finally, you might notice a smaller circumference due to atrophy of the anterior thigh muscle.

These findings should make you suspect LCPD. Your next step is to order imaging of the hips. Be sure to order bilateral X-rays, since LCPD may rarely affect both hips, even if the limp is only present on one side! Sometimes, the X-rays may seem normal, so you may also need to order an MRI to help make the diagnosis. Classic X-ray findings in LCPD include widening of the joint space and, in more severe disease, flattening or fragmentation of the femoral head. On the flip side, an MRI can reveal decreased perfusion of the femoral head. Either of these imaging findings will confirm the diagnosis of LCPD.

Once you diagnose LCPD, management depends on the degree of femoral head involvement. For limited cases with full range of motion, begin with conservative management, which includes NSAIDs, limited weight bearing, and physical therapy. On the flip side, patients with more extensive involvement or decreased range of motion may require surgical consultation; specifically, from pediatric orthopedics. Surgical management may include Petrie casting, which is a type of abduction brace that keeps the femoral head positioned within the acetabulum as it heals. More severe disease might require a surgical procedure in order to properly realign the hip, such as a femoral or pelvic osteotomy.

Now, let’s return to the focused history and physical exam, but this time let’s consider children with signs and symptoms suggesting slipped capital femoral epiphysis. Affected children are typically older than 10 years and are most often adolescents in the middle of a linear growth spurt. Patients frequently present with a limp and report pain in the hip, groin, thigh, or knee. Some risk factors for SCFE include obesity, a personal history of hypothyroidism or other endocrinopathies, trauma or radiation therapy, and a family history of SCFE.

Additionally, the physical exam will reveal limited internal rotation, abduction, and flexion of the hip. In many cases, you will notice the child’s leg externally rotating as you passively flex the hip. In some cases, the hip could even be tender to palpation.