Slipped capital femoral epiphysis (SCFE) is relatively common in pediatric patients. Subsequent contralateral SCFE is also common and rates of bilateral SCFE have been reported to range from 12% to 80% in the literature. The purpose of this study was to determine the rates of subsequent contralateral SCFE in patients who present with unilateral SCFE in the United States and determine risk factors for the development of subsequent contralateral SCFE.
The authors performed a retrospective study using data from the Pediatric Health Information System (PHIS). Patients who underwent in situ pinning of a unilateral SCFE between 2004 and 2016 were included in this study and followed prospectively to determine subsequent contralateral SCFE. They excluded patients who underwent bilateral pinning at index admission. Descriptive, univariate, and multivariate statistics were used to determine rates of subsequent contralateral SCFE and identify factors associated with contralateral SCFE.
This study included 9755 patients who underwent in situ pinning for unilateral SCFE. The mean age at the time of index SCFE was 11.9 years (SD, 1.7) and ~62% of patients were male individuals. Subsequent contralateral SCFE occurred in 1077 (11%) patients at an average of 277 days (range, 7 to 1523 d) after the index procedure. Patients who developed a subsequent contralateral SCFE were younger at the time of index SCFE than patients who did not develop a contralateral SCFE (11.3 vs. 12 y old, P<0.01). In multivariate analysis, older children had a lower risk of subsequent contralateral SCFE (adjusted odds ratio, 0.8; 95% confidence interval, 0.77-0.83), and the odds of subsequent contralateral SCFE decreased by 20% with each increasing year in age.
The rate of subsequent contralateral SCFE is ~11% in the United States, and younger patients are more likely to develop a contralateral SCFE than older patients. Prophylactic pinning should be considered in younger patients with unilateral SCFE, and patients should be followed until skeletal maturity to monitor for subsequent contralateral SCFE.
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