Dr. Antoinette Lindberg presents a case of two patients with hip pain illustrating how to recognize stable and unstable slipped capital femoral epiphysis (SCFE).
For more general information, read about slipped capital femoral epiphysis.
Patient A is a 13-year-old boy who presents to the Orthopedics Clinic with over a month of right hip pain and limping, which began after what they thought was a "muscle strain" injury at basketball camp. He weighs 139 pounds with a body mass index (BMI) of 24.
Patient B is an 11-year-old girl with over two months of left hip and groin pain. She saw her primary care provider (PCP) three weeks ago, who started her on physical therapy (PT), but the pain increased and she started using crutches the last two weeks. The night before she slipped and fell and developed severe pain in her left hip and could no longer bear weight. She was seen at her local emergency department (ED) and transferred to Seattle Children's. She weighs 167 pounds with a BMI of 28.
Both patients are presenting with a slipped capital femoral epiphysis (SCFE), but Patient A has a subtle, stable slip and Patient B has a more severe, unstable slip. "Stable" versus "unstable" SCFE is a clinical classification - a stable SCFE can still bear weight on the affected side, whereas an unstable SCFE cannot.
X-rays of Patient A are shown in Figure 1. The anteroposterior (AP) view shows some widening of the right proximal femoral physis compared to the left, but you can't really see the slip until you look at the frog-lateral views. His films are also a lesson in making sure you are not distracted by other findings. He has a left iliac wing osteochondroma (benign bone tumor) and left-sided Bertolotti malformation (bony connection between L5 and S1), neither of which are symptomatic.
X-rays of Patient B are shown in Figure 2. Her SCFE is more obvious as the proximal femoral epiphysis has completely displaced off the femoral neck.
Both patients were treated with percutaneous screw fixation to prevent further slippage and encourage the physis to close (Figures 3 and 4). In the case of a stable slip, in situ (in position) fixation is the most common, and the deformity is not corrected.
For Patient B's unstable slip, she was partially reduced prior to screw fixation. Some centers will do a larger, open procedure to realign the hip. Patients are usually placed on a limited period of weight-bearing and activity restrictions.
Mean age for an SCFE is 13.5 years for boys and 12 years for girls. SCFE also tends to be more prevalent among overweight/obese children. Younger or underweight patients should raise the suspicion for an endocrine disorder such as hypothyroidism. Patients may also present with knee or anterior thigh pain, so the diagnosis can be missed if the exam is incomplete and only knee radiographs are taken. If clinical symptoms are highly suggestive of SCFE but radiographs are equivocal, a magnetic resonance imaging (MRI) can show signs of a "pre-slip" with widening and signal changes around the physis (Figure 5). Although stable slips are usually a chronic problem, the tendency is to operate on them on a more urgent basis to prevent a fall or injury that converts the stable SCFE to an unstable SCFE.
Both patients had almost immediate resolution of their hip pain post-operatively. They have been instructed to pay close attention to any contralateral hip/knee pain they experience, as bilateral involvement has been reported at rates from 18% to 50%. Patient A will likely do well over the long term, since he was a stable slip and has very little deformity, but Patient B with the unstable SCFE has up to a 50% chance of developing osteonecrosis of the femoral head due to her slip.
- Peck D. Slipped capital femoral epiphysis: diagnosis and management. Am Fam Physician 2010;82 (3):258-62.
- Aronsson DD, Loder RT, Breur GJ, Weinstein SL. Slipped capital femoral epiphysis: current concepts. J Am Acad Orthop Surg 2006;14:666-79.
For more information, please contact Orthopedics and Sports Medicine.