Slipped Capital Femoral Epiphysis (SCFE)
SCFE can present as hip, thigh or knee pain in the young adolescent. Risk factors include hypogonadism, hypothyroidism, hypopituiratism, and obesity. One way to make the diagnosis is to obtain a AP view of the pelvis and draw a line(Klein's line) along the superior border of the neck of the femur. This line should intersect the femoral epiphysis. If it does not the diagnosis of SCFE can be made.
However, this is only about 40% sensitivity. Green et al recently published a study that demonstrated that if you measure the distance from Klein's line and the lateral edge of the femoral epiphysis on both sides, and the difference between the two is more than 2mm you can make the diagnosis of SCFE more accurately and sooner.
FIGURE 1. Measurement methods on an anterior-posterior radiograph of a right slipped capital femoral epiphysis. White lines indicate Klein’s line for each hip. A and B, indicate maximum epiphyseal width lateral to Klein’s line. As A is 2mm narrower than B, the right (A) hip qualifies as a slip using our modification but not Klein’s original definition.
Green DW, Mogekwu N, Scher DM, Handler S, Chalmers P, Widmann RF. A modification of Klein's Line to improve sensitivity of the anterior-posterior radiograph in slipped capital femoral epiphysis. J Pediatr Orthop. Jul-Aug 2009;29(5):449-453.
