Reliable X-ray diagnosis of slipped capital femoral epiphysis by combining the conventional and a new simplified geometrical method

Abstract

Background: The diagnosis of subtle slipped capital femoral epiphysis (SCFE), for example in the contralateral asymptomatic hip, may require use of an exactly defined and reproducible lateral view where the slip** angle can be measured. Objective: To test a simplified geometrical method and compare it to the conventional method (AP and frogleg views). Materials and methods: The two methods were compared in 95 normal children 9–14 years old and 100 children 9–20 years old with SCFE. Results: The slip** angle (SA) measurements had very high reproducibility, and the new method was diagnostically superior to the conventional method (P<0.05). Conclusion: An exactly defined and reproducible lateral view is recommended for the X-ray diagnosis of SCFE. Nontraumatic SCFE appears to be bilateral in all cases.