By Wudbhav N. Sankar, MD, Attending Surgeon

A 12-year-old male presented to an outside hospital after experiencing 6 weeks of pain in his left hip. He could not recall a specific injury that precipitated the symptoms, although he had fallen out of a tree 4 months earlier.

For the 2 weeks prior to presentation, his pain level had worsened to 7 out of 10. Although he was able to move about on crutches, Tylenol with codeine became insufficient to relieve his discomfort. Radiographs of both hips taken at the time of presentation to the outside institution revealed a severe slipped capital femoral epiphysis (SCFE) of the left hip. He was referred to hip specialists at The Children’s Hospital of Philadelphia for definitive care given the severity of the hip displacement and the need for a comprehensive reconstruction.

Evaluation

During our evaluation, we noted that 2 sets of radiographs had actually been obtained at the outside institution — including one around the initial onset of symptoms 6 weeks earlier. In retrospect, these older radiographs revealed a mild SCFE, which had been unrecognized at the outside hospital. When comparing the recent radiographs with this earlier study, it was clear there had been severe displacement in the interim.

The CHOP team therefore classified the patient’s type of slipped epiphysis as “unstable,” implying that the femoral epiphysis was relatively mobile and at high risk for developing avascular necrosis. As with any workup for a SCFE, the contralateral hip was evaluated for potential slip as well, but was found to be normal.

Treatment

The standard treatment for a slipped capital femoral epiphysis is in situ percutaneous screw fixation. The surgeon generally avoids manipulation of the femoral head, which can increase the risk of avascular necrosis. In the setting of an unstable SCFE, the joint is typically decompressed as well to reduce the pressure effect on the perfusing blood vessels to the femoral head.

The downside to this approach is that the surgeon accepts the displacement of the epiphysis as is, and makes no attempt to restore normal anatomy due to the risks of osteonecrosis. The residual deformity left by the SCFE, however, can cause restricted motion, pain, femoroacetabular impingement, and premature osteoarthritis.

An emerging option for this condition is an open surgical dislocation of the hip — with controlled reduction of the femoral head — performed under direct visualization. This surgical option is complex and only available at select facilities in the United States, and CHOP is one of them.

In surgery, perfusion of the femoral head is maintained by developing a posterior retinacular flap, which contains the epiphyseal vascular supply. The procedure allows anatomic reduction, and early results have demonstrated equivalent or improved avascular necrosis rates compared to standard in situ fixation.

Based on the severity of the slip and an informed discussion with the patient’s family, the CHOP team elected to proceed with the open surgical dislocation and head realignment. The contralateral hip was pinned prophylactically.

Now, at 18 months post-surgery, the patient has returned to all activities including hiking and sports. He is pain-free and has equivalent function/motion in his affected side as his contralateral limb.

 

Learn more about the Hip Disorders Program at CHOP.