The Atypical Patient With Slipped Capital Femoral Epiphyses May Be at Increased Risk for a Missed Contralateral Slip

Area of Science:

• Pediatric Orthopedics
• Skeletal Disorders
• Hip Pathology

Background:

• Slipped capital femoral epiphysis (SCFE) is a common hip disorder in children and adolescents.
• Identifying bilateral involvement is crucial for optimal patient outcomes.
• Previous studies have not fully elucidated risk factors for missed contralateral SCFE.

Purpose of the Study:

• To determine the incidence of missed contralateral SCFE.
• To identify demographic and radiographic risk factors associated with missed contralateral SCFE.
• To evaluate the role of surgeon training in identifying bilateral SCFE.

Main Methods:

• Retrospective chart and radiograph review of pediatric patients with sequential and bilateral SCFE over 18 years.
• Radiographs assessed for skeletal maturity, Klein's line, and slip severity by three pediatric orthopedists.
• Statistical analysis using Fisher's exact test to compare groups.

Main Results:

• Five of 56 patients (8.9%) with bilateral SCFE had a missed contralateral slip.
• Missed slips were more common in younger patients (mean age 10.8 years) with lower BMI.
• Positive Klein's line findings were strongly associated with contralateral slips (P<.0001); severity of the treated slip was not a predictor.
• Fellowship-trained pediatric orthopedic surgeons were more likely to identify bilateral disease (P=.0065).

Conclusions:

• A significant incidence of missed contralateral SCFE exists, particularly in younger, lower BMI patients.
• Klein's line is a valuable but not infallible diagnostic tool, with a 40% false-negative rate observed.
• Increased vigilance is recommended for "atypical" unilateral SCFE presentations to prevent missed contralateral disease.