Slipped Capital Femoral Epiphysis

  • Etiology: posteromedial epiphyseal slip / Salter-Harris Type I fracture due to repeated trauma
  • Radiograph: pre-slip – physeal widening is earliest sign, femoral head slips posteromedial (seen better on lateral view), line of Klein drawn over lateral aspect of femoral neck should intersect ~ 1/6th of femoral head, make sure to image both hips for comparison purposes and 25% of cases are bilateral
  • MRI: physeal widening, metaphyseal marrow edema adjacent to physis, joint effusion, synovitis, +/- epiphyseal displacement
  • Complications: osteoarthritis, avascular necrosis of femoral head, chondrolysis, femoroacetabular impingement, leg length discrepancy
  • Treatment: surgically stabilized via screw without reduction of prexisting slip due to increased risk of post operative osteonecrosis associated with slip reduction
  • Clinical: presents with hip pain which progresses to limp, seen in older (13 year olds) vs Legg-Calve-Perthes (in 4-8 year olds), 25% bilateral, risk factors – obesity / endocrine / delayed skeletal maturation / family history / hip trauma / decreased femoral anteversion

Radiology Cases of Slipped Capital Femoral Epiphysis

Radiograph and CT of slipped capital femoral epiphysis
AP radiograph of the pelvis (upper left) shows the left femoral metaphysis to be displaced laterally from its epiphysis. This is better demonstrated on the coronal CT without contrast of the pelvis (upper right) and 3D CT of the pelvis (below)
Radiograph and CT of slipped capital femoral epiphysis
AP radiograph of the pelvis shows a fracture through the left physeal growth plate causing the femoral epiphysis to sublux off of the femoral metaphysis. This is more clearly seen on the coronal 2D reconstruction CT of the pelvis.
Radiograph of slipped capital femoral epiphysis
Frogleg radiograph of the pelvis shows a fracture through the right physeal growth plate causing the femoral epiphysis to sublux off of the femoral metaphysis.
Radiograph of Legg-Calve-Perthes disease and slipped capital femoral epiphysis
AP (above) and frogleg (below) radiographs of the pelvis shows the right femoral head to be flat and enlarged with femoral neck shortening. The left femoral epiphysis is slipped posteromedially.